This page is intended to provide short, legible descriptions of common water contaminants, with a...
Public Lab is an open community which collaboratively develops accessible, open source, Do-It-Yourself technologies for investigating local environmental health and justice issues.
| 35 | eustatic |
April 30, 2014 01:50
| over 10 years ago
Purpose of this wikiThis wiki is intended to provide short, legible descriptions of common water contaminants, with a no-nonsense rundown on what methods might be used to both assess and address the presence of these contaminants. We're aiming to pay special attention to the relative cost and technical expertise required for each method. For example, some of these contaminants might be readily addressed by simple, cheap home testing kits. Some of them might currently require expensive laboratory testing. For many of them, the EPA and others have published protocols for how to assess the level of these contaminants in a laboratory setting; we'd like to begin to collect links to these protocols, labeling them as "possibly DIY?" or "DIY: implausible", etc ... Suggested format for entries:
Please help us fill out this list with relevant info about important water contaminants ... GlyphosateWhy is it a problem? How does it enter the water supply?Glyphosate is a commonly used pesticide sold under trademarks such as Monsanto's 'Roundup'. that enters the water supply via agricultural runoff. The EPA information site for glyphosate is here. How much is safe?Experts disagree on safe levels; the EPA has set a legally enforceable maximum contaminant level (MCL) for glyphosate of 700 ug/l in drinking water, which is 7,000 times higher than the MCL in Europe. How is it tested?Possible testing methods include:
a) laboratory tests, for $110 - $300 (links to more info here). Most likely, these tests use a technique called ELISA. ELISA is an acronym for Enzyme Linked Immunosorbent Assay. This type of assay uses antibodies to bind the analyte (glyphosate) and an enzyme reaction to generate a color change. This type of assay is routinely used in pregnancy and drug tests. A discussion of ELISAs can be found here. Various companies make these kits, such as here.
b) spectroscopy (see Public Lab's Spectroscopy Kit). Since glyphosate is colorless, direct measurement cannot be done via visible spectrometry. The ultraviolet spectrum at neutral pH (found here) shows an absorbance maximum at ~200 nm with an extinction coefficient of ~62. The same source shows that this value is similar to other carboxylic acids, such as acetic acid. Since common acids and other organic materials will interfere with detection by UV spectroscopy, this is not a recommended method.
An indirect spectroscopic method has been proposed here under "experiment 5":
http://publiclab.org/wiki/pesticide-detection-methods-development. This method relies on chemistry established for determining inorganic phosphate (PO43-) and measures the visible absorbance of a reaction product (This method is probably the molybdenum blue method, described on page 672 of Vogel's textbook of quantitative chemical analysis, 6th edition). Unfortunately, the citation does not claim that the method has been tested for glyphosate and shown to give the colored product. Since glyphosate is not inorganic phosphate (it is an organic phosphonate, having a carbon-phosphorus bond), the test needs to be run to ensure that it reacts to give the colored product. What can be done about it?Links to more infohttp://www.organicconsumers.org/articles/article_29696.cfm Endocrine disruptors[edit] Mercury[question:mercury] Why is it a problem? How does it enter the water supply?sources: produced water, aerial deposition into wetland ecosystems, aerial deposition downwind of coal-fired power plants Chromium[edit] sources: produced water Barium[edit] sources: produced water Arsenic[edit] sources: produced water Lead[edit] sources: produced water Oil and Grease-TPH Volatiles -TPH Gasoline -TPH Diesel and Oil Nitrogen: Nitrates, Nitrite, Ammonia, & AmmoniumNitrates, Nitrite, Ammonia, & Ammonium are "fixed" forms of nitrogen available to living organisms, and represent different stages of nitrogen in the nitrogen cycle. Nitrogen is a major limiting nutrient in plant growth-- when nitrates occur in large quantities in water from fertilizers, manure, or sewage runoff, they can cause algal blooms that create dead zones. Nitrates have also been linked to increased risks of cancer, and complications with a number of diseases, including asthma. The EPA limits drinking water concentrations of Nitrates to 10mg/L or lower, however, health threats can occur even at those levels. Ammonia (NH3) and ammonium ion (NH4+) are related chemically by an acid / base reaction: NH3 + H+ <=> NH4+ The equilibrium between ammonia and ammonium is pH dependent, with the two species being at the same concentration only under fairly alkaline conditions, pH = 9.25. At neutral pH, the concentration of free NH3 is less than 1% that of NH4+. Since this is the case, the concentration of ammonia is usually not significant and can be determined from the concentration of ammonium and the pH. Assaying NitrogenThe wet lab Kjeldahl Method is often used to get the measurement TKN, or Total Kjeldahl Nitrogen. EPA Method 353.2 involves a cobalt catalyst and spectroscopy in the visible range. UV SpectroscopyIn Situ Underwater Spectroscopy (UV in the ocean): TSS, BOD, and Nitrate with a single 200nm-720nm spectrometer ON-LINE NITRATE MONITORING IN SEWERS USING UV/VIS SPECTROSCOPY F. Hofstaedter, T. Ertl, G. Langergraber, W. Lettl, A. Weingartne Potentiometric Measurements of Nitrate and Ammonium using Ion Selective ElectrodesIon selective electrodes (discussed here) can be used to conveniently measure ammonium and nitrate. These electrodes behave similarly to commonly used pH electrodes. The main difference between a pH electrode and an ion selective electrode (ISE) is that the former has a glass surface that is electrically polarized by protons and the latter has a membrane that is responsive to the ion in question. Like a pH electrode, an ion selective electrode responds to changes in analyte concentration by a measurable change in voltage. Ion selective electrodes can be measured with most pH meters. These electrodes can be purchased from a variety of sources (VWR, Fisher, etc) but are somewhat more expensive than pH electrodes. Vernier sells ammonium and nitrate sensitive electrodes (here) for $179 each. Road saltRoad salt is detrimental both to aquatic life and to plants. In Canada, it was classified as a toxic substance, but then, since so much was being used to keep roads safe, they did not carry through with measures to reduce it, only voluntary guidelines. Conductivity is a surrogate for chloride content. In Stoney Creek in Burnaby, BC, conductivity follows a linear relationship to chloride concentration. Chloride in mg/L=(0.3013 x SpCond - 16.095) |
Revert | |
| 34 | eustatic |
April 30, 2014 01:44
| over 10 years ago
Purpose of this wikiThis wiki is intended to provide short, legible descriptions of common water contaminants, with a no-nonsense rundown on what methods might be used to both assess and address the presence of these contaminants. We're aiming to pay special attention to the relative cost and technical expertise required for each method. For example, some of these contaminants might be readily addressed by simple, cheap home testing kits. Some of them might currently require expensive laboratory testing. For many of them, the EPA and others have published protocols for how to assess the level of these contaminants in a laboratory setting; we'd like to begin to collect links to these protocols, labeling them as "possibly DIY?" or "DIY: implausible", etc ... Suggested format for entries:
Please help us fill out this list with relevant info about important water contaminants ... GlyphosateWhy is it a problem? How does it enter the water supply?Glyphosate is a commonly used pesticide sold under trademarks such as Monsanto's 'Roundup'. that enters the water supply via agricultural runoff. The EPA information site for glyphosate is here. How much is safe?Experts disagree on safe levels; the EPA has set a legally enforceable maximum contaminant level (MCL) for glyphosate of 700 ug/l in drinking water, which is 7,000 times higher than the MCL in Europe. How is it tested?Possible testing methods include:
a) laboratory tests, for $110 - $300 (links to more info here). Most likely, these tests use a technique called ELISA. ELISA is an acronym for Enzyme Linked Immunosorbent Assay. This type of assay uses antibodies to bind the analyte (glyphosate) and an enzyme reaction to generate a color change. This type of assay is routinely used in pregnancy and drug tests. A discussion of ELISAs can be found here. Various companies make these kits, such as here.
b) spectroscopy (see Public Lab's Spectroscopy Kit). Since glyphosate is colorless, direct measurement cannot be done via visible spectrometry. The ultraviolet spectrum at neutral pH (found here) shows an absorbance maximum at ~200 nm with an extinction coefficient of ~62. The same source shows that this value is similar to other carboxylic acids, such as acetic acid. Since common acids and other organic materials will interfere with detection by UV spectroscopy, this is not a recommended method.
An indirect spectroscopic method has been proposed here under "experiment 5":
http://publiclab.org/wiki/pesticide-detection-methods-development. This method relies on chemistry established for determining inorganic phosphate (PO43-) and measures the visible absorbance of a reaction product (This method is probably the molybdenum blue method, described on page 672 of Vogel's textbook of quantitative chemical analysis, 6th edition). Unfortunately, the citation does not claim that the method has been tested for glyphosate and shown to give the colored product. Since glyphosate is not inorganic phosphate (it is an organic phosphonate, having a carbon-phosphorus bond), the test needs to be run to ensure that it reacts to give the colored product. What can be done about it?Links to more infohttp://www.organicconsumers.org/articles/article_29696.cfm Endocrine disruptors[edit] Mercury[question:mercury] sources: produced water Chromium[edit] sources: produced water Barium[edit] sources: produced water Arsenic[edit] sources: produced water Lead[edit] sources: produced water Oil and Grease-TPH Volatiles -TPH Gasoline -TPH Diesel and Oil Nitrogen: Nitrates, Nitrite, Ammonia, & AmmoniumNitrates, Nitrite, Ammonia, & Ammonium are "fixed" forms of nitrogen available to living organisms, and represent different stages of nitrogen in the nitrogen cycle. Nitrogen is a major limiting nutrient in plant growth-- when nitrates occur in large quantities in water from fertilizers, manure, or sewage runoff, they can cause algal blooms that create dead zones. Nitrates have also been linked to increased risks of cancer, and complications with a number of diseases, including asthma. The EPA limits drinking water concentrations of Nitrates to 10mg/L or lower, however, health threats can occur even at those levels. Ammonia (NH3) and ammonium ion (NH4+) are related chemically by an acid / base reaction: NH3 + H+ <=> NH4+ The equilibrium between ammonia and ammonium is pH dependent, with the two species being at the same concentration only under fairly alkaline conditions, pH = 9.25. At neutral pH, the concentration of free NH3 is less than 1% that of NH4+. Since this is the case, the concentration of ammonia is usually not significant and can be determined from the concentration of ammonium and the pH. Assaying NitrogenThe wet lab Kjeldahl Method is often used to get the measurement TKN, or Total Kjeldahl Nitrogen. EPA Method 353.2 involves a cobalt catalyst and spectroscopy in the visible range. UV SpectroscopyIn Situ Underwater Spectroscopy (UV in the ocean): TSS, BOD, and Nitrate with a single 200nm-720nm spectrometer ON-LINE NITRATE MONITORING IN SEWERS USING UV/VIS SPECTROSCOPY F. Hofstaedter, T. Ertl, G. Langergraber, W. Lettl, A. Weingartne Potentiometric Measurements of Nitrate and Ammonium using Ion Selective ElectrodesIon selective electrodes (discussed here) can be used to conveniently measure ammonium and nitrate. These electrodes behave similarly to commonly used pH electrodes. The main difference between a pH electrode and an ion selective electrode (ISE) is that the former has a glass surface that is electrically polarized by protons and the latter has a membrane that is responsive to the ion in question. Like a pH electrode, an ion selective electrode responds to changes in analyte concentration by a measurable change in voltage. Ion selective electrodes can be measured with most pH meters. These electrodes can be purchased from a variety of sources (VWR, Fisher, etc) but are somewhat more expensive than pH electrodes. Vernier sells ammonium and nitrate sensitive electrodes (here) for $179 each. Road saltRoad salt is detrimental both to aquatic life and to plants. In Canada, it was classified as a toxic substance, but then, since so much was being used to keep roads safe, they did not carry through with measures to reduce it, only voluntary guidelines. Conductivity is a surrogate for chloride content. In Stoney Creek in Burnaby, BC, conductivity follows a linear relationship to chloride concentration. Chloride in mg/L=(0.3013 x SpCond - 16.095) |
Revert | |
| 33 | eustatic |
April 30, 2014 01:43
| over 10 years ago
Purpose of this wikiThis wiki is intended to provide short, legible descriptions of common water contaminants, with a no-nonsense rundown on what methods might be used to both assess and address the presence of these contaminants. We're aiming to pay special attention to the relative cost and technical expertise required for each method. For example, some of these contaminants might be readily addressed by simple, cheap home testing kits. Some of them might currently require expensive laboratory testing. For many of them, the EPA and others have published protocols for how to assess the level of these contaminants in a laboratory setting; we'd like to begin to collect links to these protocols, labeling them as "possibly DIY?" or "DIY: implausible", etc ... Suggested format for entries:
Please help us fill out this list with relevant info about important water contaminants ... GlyphosateWhy is it a problem? How does it enter the water supply?Glyphosate is a commonly used pesticide sold under trademarks such as Monsanto's 'Roundup'. that enters the water supply via agricultural runoff. The EPA information site for glyphosate is here. How much is safe?Experts disagree on safe levels; the EPA has set a legally enforceable maximum contaminant level (MCL) for glyphosate of 700 ug/l in drinking water, which is 7,000 times higher than the MCL in Europe. How is it tested?Possible testing methods include:
a) laboratory tests, for $110 - $300 (links to more info here). Most likely, these tests use a technique called ELISA. ELISA is an acronym for Enzyme Linked Immunosorbent Assay. This type of assay uses antibodies to bind the analyte (glyphosate) and an enzyme reaction to generate a color change. This type of assay is routinely used in pregnancy and drug tests. A discussion of ELISAs can be found here. Various companies make these kits, such as here.
b) spectroscopy (see Public Lab's Spectroscopy Kit). Since glyphosate is colorless, direct measurement cannot be done via visible spectrometry. The ultraviolet spectrum at neutral pH (found here) shows an absorbance maximum at ~200 nm with an extinction coefficient of ~62. The same source shows that this value is similar to other carboxylic acids, such as acetic acid. Since common acids and other organic materials will interfere with detection by UV spectroscopy, this is not a recommended method.
An indirect spectroscopic method has been proposed here under "experiment 5":
http://publiclab.org/wiki/pesticide-detection-methods-development. This method relies on chemistry established for determining inorganic phosphate (PO43-) and measures the visible absorbance of a reaction product (This method is probably the molybdenum blue method, described on page 672 of Vogel's textbook of quantitative chemical analysis, 6th edition). Unfortunately, the citation does not claim that the method has been tested for glyphosate and shown to give the colored product. Since glyphosate is not inorganic phosphate (it is an organic phosphonate, having a carbon-phosphorus bond), the test needs to be run to ensure that it reacts to give the colored product. What can be done about it?Links to more infohttp://www.organicconsumers.org/articles/article_29696.cfm Endocrine disruptors[edit] Mercury[question:mercury] sources: produced waterChromium[edit] sources: produced water Barium[edit] sources: produced waterArsenic[edit] sources: produced water Lead[edit] sources: produced water Oil and Grease-TPH Volatiles -TPH Gasoline -TPH Diesel and Oil Nitrogen: Nitrates, Nitrite, Ammonia, & AmmoniumNitrates, Nitrite, Ammonia, & Ammonium are "fixed" forms of nitrogen available to living organisms, and represent different stages of nitrogen in the nitrogen cycle. Nitrogen is a major limiting nutrient in plant growth-- when nitrates occur in large quantities in water from fertilizers, manure, or sewage runoff, they can cause algal blooms that create dead zones. Nitrates have also been linked to increased risks of cancer, and complications with a number of diseases, including asthma. The EPA limits drinking water concentrations of Nitrates to 10mg/L or lower, however, health threats can occur even at those levels. Ammonia (NH3) and ammonium ion (NH4+) are related chemically by an acid / base reaction: NH3 + H+ <=> NH4+ The equilibrium between ammonia and ammonium is pH dependent, with the two species being at the same concentration only under fairly alkaline conditions, pH = 9.25. At neutral pH, the concentration of free NH3 is less than 1% that of NH4+. Since this is the case, the concentration of ammonia is usually not significant and can be determined from the concentration of ammonium and the pH. Assaying NitrogenThe wet lab Kjeldahl Method is often used to get the measurement TKN, or Total Kjeldahl Nitrogen. EPA Method 353.2 involves a cobalt catalyst and spectroscopy in the visible range. UV SpectroscopyIn Situ Underwater Spectroscopy (UV in the ocean): TSS, BOD, and Nitrate with a single 200nm-720nm spectrometer ON-LINE NITRATE MONITORING IN SEWERS USING UV/VIS SPECTROSCOPY F. Hofstaedter, T. Ertl, G. Langergraber, W. Lettl, A. Weingartne Potentiometric Measurements of Nitrate and Ammonium using Ion Selective ElectrodesIon selective electrodes (discussed here) can be used to conveniently measure ammonium and nitrate. These electrodes behave similarly to commonly used pH electrodes. The main difference between a pH electrode and an ion selective electrode (ISE) is that the former has a glass surface that is electrically polarized by protons and the latter has a membrane that is responsive to the ion in question. Like a pH electrode, an ion selective electrode responds to changes in analyte concentration by a measurable change in voltage. Ion selective electrodes can be measured with most pH meters. These electrodes can be purchased from a variety of sources (VWR, Fisher, etc) but are somewhat more expensive than pH electrodes. Vernier sells ammonium and nitrate sensitive electrodes (here) for $179 each. Road saltRoad salt is detrimental both to aquatic life and to plants. In Canada, it was classified as a toxic substance, but then, since so much was being used to keep roads safe, they did not carry through with measures to reduce it, only voluntary guidelines. Conductivity is a surrogate for chloride content. In Stoney Creek in Burnaby, BC, conductivity follows a linear relationship to chloride concentration. Chloride in mg/L=(0.3013 x SpCond - 16.095) |
Revert | |
| 32 | warren |
April 25, 2014 21:13
| over 10 years ago
Purpose of this wikiThis wiki is intended to provide short, legible descriptions of common water contaminants, with a no-nonsense rundown on what methods might be used to both assess and address the presence of these contaminants. We're aiming to pay special attention to the relative cost and technical expertise required for each method. For example, some of these contaminants might be readily addressed by simple, cheap home testing kits. Some of them might currently require expensive laboratory testing. For many of them, the EPA and others have published protocols for how to assess the level of these contaminants in a laboratory setting; we'd like to begin to collect links to these protocols, labeling them as "possibly DIY?" or "DIY: implausible", etc ... Suggested format for entries:
Please help us fill out this list with relevant info about important water contaminants ... GlyphosateWhy is it a problem? How does it enter the water supply?Glyphosate is a commonly used pesticide sold under trademarks such as Monsanto's 'Roundup'. that enters the water supply via agricultural runoff. The EPA information site for glyphosate is here. How much is safe?Experts disagree on safe levels; the EPA has set a legally enforceable maximum contaminant level (MCL) for glyphosate of 700 ug/l in drinking water, which is 7,000 times higher than the MCL in Europe. How is it tested?Possible testing methods include:
a) laboratory tests, for $110 - $300 (links to more info here). Most likely, these tests use a technique called ELISA. ELISA is an acronym for Enzyme Linked Immunosorbent Assay. This type of assay uses antibodies to bind the analyte (glyphosate) and an enzyme reaction to generate a color change. This type of assay is routinely used in pregnancy and drug tests. A discussion of ELISAs can be found here. Various companies make these kits, such as here.
b) spectroscopy (see Public Lab's Spectroscopy Kit). Since glyphosate is colorless, direct measurement cannot be done via visible spectrometry. The ultraviolet spectrum at neutral pH (found here) shows an absorbance maximum at ~200 nm with an extinction coefficient of ~62. The same source shows that this value is similar to other carboxylic acids, such as acetic acid. Since common acids and other organic materials will interfere with detection by UV spectroscopy, this is not a recommended method.
An indirect spectroscopic method has been proposed here under "experiment 5":
http://publiclab.org/wiki/pesticide-detection-methods-development. This method relies on chemistry established for determining inorganic phosphate (PO43-) and measures the visible absorbance of a reaction product (This method is probably the molybdenum blue method, described on page 672 of Vogel's textbook of quantitative chemical analysis, 6th edition). Unfortunately, the citation does not claim that the method has been tested for glyphosate and shown to give the colored product. Since glyphosate is not inorganic phosphate (it is an organic phosphonate, having a carbon-phosphorus bond), the test needs to be run to ensure that it reacts to give the colored product. What can be done about it?Links to more infohttp://www.organicconsumers.org/articles/article_29696.cfm Endocrine disruptors[edit] Mercury[question:mercury] Arsenic[edit] Lead[edit] Oil and Grease-TPH Volatiles -TPH Gasoline -TPH Diesel and Oil Nitrogen: Nitrates, Nitrite, Ammonia, & AmmoniumNitrates, Nitrite, Ammonia, & Ammonium are "fixed" forms of nitrogen available to living organisms, and represent different stages of nitrogen in the nitrogen cycle. Nitrogen is a major limiting nutrient in plant growth-- when nitrates occur in large quantities in water from fertilizers, manure, or sewage runoff, they can cause algal blooms that create dead zones. Nitrates have also been linked to increased risks of cancer, and complications with a number of diseases, including asthma. The EPA limits drinking water concentrations of Nitrates to 10mg/L or lower, however, health threats can occur even at those levels. Ammonia (NH3) and ammonium ion (NH4+) are related chemically by an acid / base reaction: NH3 + H+ <=> NH4+ The equilibrium between ammonia and ammonium is pH dependent, with the two species being at the same concentration only under fairly alkaline conditions, pH = 9.25. At neutral pH, the concentration of free NH3 is less than 1% that of NH4+. Since this is the case, the concentration of ammonia is usually not significant and can be determined from the concentration of ammonium and the pH. Assaying NitrogenThe wet lab Kjeldahl Method is often used to get the measurement TKN, or Total Kjeldahl Nitrogen. EPA Method 353.2 involves a cobalt catalyst and spectroscopy in the visible range. UV SpectroscopyIn Situ Underwater Spectroscopy (UV in the ocean): TSS, BOD, and Nitrate with a single 200nm-720nm spectrometer ON-LINE NITRATE MONITORING IN SEWERS USING UV/VIS SPECTROSCOPY F. Hofstaedter, T. Ertl, G. Langergraber, W. Lettl, A. Weingartne Potentiometric Measurements of Nitrate and Ammonium using Ion Selective ElectrodesIon selective electrodes (discussed here) can be used to conveniently measure ammonium and nitrate. These electrodes behave similarly to commonly used pH electrodes. The main difference between a pH electrode and an ion selective electrode (ISE) is that the former has a glass surface that is electrically polarized by protons and the latter has a membrane that is responsive to the ion in question. Like a pH electrode, an ion selective electrode responds to changes in analyte concentration by a measurable change in voltage. Ion selective electrodes can be measured with most pH meters. These electrodes can be purchased from a variety of sources (VWR, Fisher, etc) but are somewhat more expensive than pH electrodes. Vernier sells ammonium and nitrate sensitive electrodes (here) for $179 each. Road saltRoad salt is detrimental both to aquatic life and to plants. In Canada, it was classified as a toxic substance, but then, since so much was being used to keep roads safe, they did not carry through with measures to reduce it, only voluntary guidelines. Conductivity is a surrogate for chloride content. In Stoney Creek in Burnaby, BC, conductivity follows a linear relationship to chloride concentration. Chloride in mg/L=(0.3013 x SpCond - 16.095) |
Revert | |
| 31 | warren |
April 23, 2014 23:41
| over 10 years ago
Purpose of this wikiThis wiki is intended to provide short, legible descriptions of common water contaminants, with a no-nonsense rundown on what methods might be used to both assess and address the presence of these contaminants. We're aiming to pay special attention to the relative cost and technical expertise required for each method. For example, some of these contaminants might be readily addressed by simple, cheap home testing kits. Some of them might currently require expensive laboratory testing. For many of them, the EPA and others have published protocols for how to assess the level of these contaminants in a laboratory setting; we'd like to begin to collect links to these protocols, labeling them as "possibly DIY?" or "DIY: implausible", etc ... Suggested format for entries:
Please help us fill out this list with relevant info about important water contaminants ... GlyphosateWhy is it a problem? How does it enter the water supply?Glyphosate is a commonly used pesticide sold under trademarks such as Monsanto's 'Roundup'. that enters the water supply via agricultural runoff. The EPA information site for glyphosate is here. How much is safe?Experts disagree on safe levels; the EPA has set a legally enforceable maximum contaminant level (MCL) for glyphosate of 700 ug/l in drinking water, which is 7,000 times higher than the MCL in Europe. How is it tested?Possible testing methods include:
a) laboratory tests, for $110 - $300 (links to more info here). Most likely, these tests use a technique called ELISA. ELISA is an acronym for Enzyme Linked Immunosorbent Assay. This type of assay uses antibodies to bind the analyte (glyphosate) and an enzyme reaction to generate a color change. This type of assay is routinely used in pregnancy and drug tests. A discussion of ELISAs can be found here. Various companies make these kits, such as here.
b) spectroscopy (see Public Lab's Spectroscopy Kit). Since glyphosate is colorless, direct measurement cannot be done via visible spectrometry. The ultraviolet spectrum at neutral pH (found here) shows an absorbance maximum at ~200 nm with an extinction coefficient of ~62. The same source shows that this value is similar to other carboxylic acids, such as acetic acid. Since common acids and other organic materials will interfere with detection by UV spectroscopy, this is not a recommended method.
An indirect spectroscopic method has been proposed here under "experiment 5":
http://publiclab.org/wiki/pesticide-detection-methods-development. This method relies on chemistry established for determining inorganic phosphate (PO43-) and measures the visible absorbance of a reaction product (This method is probably the molybdenum blue method, described on page 672 of Vogel's textbook of quantitative chemical analysis, 6th edition). Unfortunately, the citation does not claim that the method has been tested for glyphosate and shown to give the colored product. Since glyphosate is not inorganic phosphate (it is an organic phosphonate, having a carbon-phosphorus bond), the test needs to be run to ensure that it reacts to give the colored product. What can be done about it?Links to more infohttp://www.organicconsumers.org/articles/article_29696.cfm Endocrine disruptors[edit] Mercury[edit] Arsenic[edit] Lead[edit] Oil and Grease-TPH Volatiles -TPH Gasoline -TPH Diesel and Oil Nitrogen: Nitrates, Nitrite, Ammonia, & AmmoniumNitrates, Nitrite, Ammonia, & Ammonium are "fixed" forms of nitrogen available to living organisms, and represent different stages of nitrogen in the nitrogen cycle. Nitrogen is a major limiting nutrient in plant growth-- when nitrates occur in large quantities in water from fertilizers, manure, or sewage runoff, they can cause algal blooms that create dead zones. Nitrates have also been linked to increased risks of cancer, and complications with a number of diseases, including asthma. The EPA limits drinking water concentrations of Nitrates to 10mg/L or lower, however, health threats can occur even at those levels. Ammonia (NH3) and ammonium ion (NH4+) are related chemically by an acid / base reaction: NH3 + H+ <=> NH4+ The equilibrium between ammonia and ammonium is pH dependent, with the two species being at the same concentration only under fairly alkaline conditions, pH = 9.25. At neutral pH, the concentration of free NH3 is less than 1% that of NH4+. Since this is the case, the concentration of ammonia is usually not significant and can be determined from the concentration of ammonium and the pH. Assaying NitrogenThe wet lab Kjeldahl Method is often used to get the measurement TKN, or Total Kjeldahl Nitrogen. EPA Method 353.2 involves a cobalt catalyst and spectroscopy in the visible range. UV SpectroscopyIn Situ Underwater Spectroscopy (UV in the ocean): TSS, BOD, and Nitrate with a single 200nm-720nm spectrometer ON-LINE NITRATE MONITORING IN SEWERS USING UV/VIS SPECTROSCOPY F. Hofstaedter, T. Ertl, G. Langergraber, W. Lettl, A. Weingartne Potentiometric Measurements of Nitrate and Ammonium using Ion Selective ElectrodesIon selective electrodes (discussed here) can be used to conveniently measure ammonium and nitrate. These electrodes behave similarly to commonly used pH electrodes. The main difference between a pH electrode and an ion selective electrode (ISE) is that the former has a glass surface that is electrically polarized by protons and the latter has a membrane that is responsive to the ion in question. Like a pH electrode, an ion selective electrode responds to changes in analyte concentration by a measurable change in voltage. Ion selective electrodes can be measured with most pH meters. These electrodes can be purchased from a variety of sources (VWR, Fisher, etc) but are somewhat more expensive than pH electrodes. Vernier sells ammonium and nitrate sensitive electrodes (here) for $179 each. Road saltRoad salt is detrimental both to aquatic life and to plants. In Canada, it was classified as a toxic substance, but then, since so much was being used to keep roads safe, they did not carry through with measures to reduce it, only voluntary guidelines. Conductivity is a surrogate for chloride content. In Stoney Creek in Burnaby, BC, conductivity follows a linear relationship to chloride concentration. Chloride in mg/L=(0.3013 x SpCond - 16.095) |
Revert | |
| 30 | JSummers |
April 22, 2014 18:26
| over 10 years ago
Purpose of this wikiThis wiki is intended to provide short, legible descriptions of common water contaminants, with a no-nonsense rundown on what methods might be used to both assess and address the presence of these contaminants. We're aiming to pay special attention to the relative cost and technical expertise required for each method. For example, some of these contaminants might be readily addressed by simple, cheap home testing kits. Some of them might currently require expensive laboratory testing. For many of them, the EPA and others have published protocols for how to assess the level of these contaminants in a laboratory setting; we'd like to begin to collect links to these protocols, labeling them as "possibly DIY?" or "DIY: implausible", etc ... Suggested format for entries:
Please help us fill out this list with relevant info about important water contaminants ... GlyphosateWhy is it a problem? How does it enter the water supply?Glyphosate is a commonly used pesticide sold under trademarks such as Monsanto's 'Roundup'. that enters the water supply via agricultural runoff. The EPA information site for glyphosate is here. How much is safe?Experts disagree on safe levels; the EPA has set a legally enforceable maximum contaminant level (MCL) for glyphosate of 700 ug/l in drinking water, which is 7,000 times higher than the MCL in Europe. How is it tested?Possible testing methods include:
a) laboratory tests, for $110 - $300 (links to more info here). Most likely, these tests use a technique called ELISA. ELISA is an acronym for Enzyme Linked Immunosorbent Assay. This type of assay uses antibodies to bind the analyte (glyphosate) and an enzyme reaction to generate a color change. This type of assay is routinely used in pregnancy and drug tests. A discussion of ELISAs can be found here. Various companies make these kits, such as here.
b) spectroscopy (see Public Lab's Spectroscopy Kit). Since glyphosate is colorless, direct measurement cannot be done via visible spectrometry. The ultraviolet spectrum at neutral pH (found here) shows an absorbance maximum at ~200 nm with an extinction coefficient of ~62. The same source shows that this value is similar to other carboxylic acids, such as acetic acid. Since common acids and other organic materials will interfere with detection by UV spectroscopy, this is not a recommended method.
An indirect spectroscopic method has been proposed here under "experiment 5":
http://publiclab.org/wiki/pesticide-detection-methods-development. This method relies on chemistry established for determining inorganic phosphate (PO43-) and measures the visible absorbance of a reaction product (This method is probably the molybdenum blue method, described on page 672 of Vogel's textbook of quantitative chemical analysis, 6th edition). Unfortunately, the citation does not claim that the method has been tested for glyphosate and shown to give the colored product. Since glyphosate is not inorganic phosphate (it is an organic phosphonate, having a carbon-phosphorus bond), the test needs to be run to ensure that it reacts to give the colored product. What can be done about it?Links to more infohttp://www.organicconsumers.org/articles/article_29696.cfm Endocrine disruptorsMercuryArsenicLeadOil and Grease-TPH Volatiles -TPH Gasoline -TPH Diesel and Oil Nitrogen: Nitrates, Nitrite, Ammonia, & AmmoniumNitrates, Nitrite, Ammonia, & Ammonium are "fixed" forms of nitrogen available to living organisms, and represent different stages of nitrogen in the nitrogen cycle. Nitrogen is a major limiting nutrient in plant growth-- when nitrates occur in large quantities in water from fertilizers, manure, or sewage runoff, they can cause algal blooms that create dead zones. Nitrates have also been linked to increased risks of cancer, and complications with a number of diseases, including asthma. The EPA limits drinking water concentrations of Nitrates to 10mg/L or lower, however, health threats can occur even at those levels. Ammonia (NH3) and ammonium ion (NH4+) are related chemically by an acid / base reaction: NH3 + H+ <=> NH4+ The equilibrium between ammonia and ammonium is pH dependent, with the two species being at the same concentration only under fairly alkaline conditions, pH = 9.25. At neutral pH, the concentration of free NH3 is less than 1% that of NH4+. Since this is the case, the concentration of ammonia is usually not significant and can be determined from the concentration of ammonium and the pH. Assaying NitrogenThe wet lab Kjeldahl Method is often used to get the measurement TKN, or Total Kjeldahl Nitrogen. EPA Method 353.2 involves a cobalt catalyst and spectroscopy in the visible range. UV SpectroscopyIn Situ Underwater Spectroscopy (UV in the ocean): TSS, BOD, and Nitrate with a single 200nm-720nm spectrometer ON-LINE NITRATE MONITORING IN SEWERS USING UV/VIS SPECTROSCOPY F. Hofstaedter, T. Ertl, G. Langergraber, W. Lettl, A. Weingartne Potentiometric Measurements of Nitrate and Ammonium using Ion Selective ElectrodesIon selective electrodes (discussed here) can be used to conveniently measure ammonium and nitrate. These electrodes behave similarly to commonly used pH electrodes. The main difference between a pH electrode and an ion selective electrode (ISE) is that the former has a glass surface that is electrically polarized by protons and the latter has a membrane that is responsive to the ion in question. Like a pH electrode, an ion selective electrode responds to changes in analyte concentration by a measurable change in voltage. Ion selective electrodes can be measured with most pH meters. These electrodes can be purchased from a variety of sources (VWR, Fisher, etc) but are somewhat more expensive than pH electrodes. Vernier sells ammonium and nitrate sensitive electrodes (here) for $179 each. Road saltRoad salt is detrimental both to aquatic life and to plants. In Canada, it was classified as a toxic substance, but then, since so much was being used to keep roads safe, they did not carry through with measures to reduce it, only voluntary guidelines. Conductivity is a surrogate for chloride content. In Stoney Creek in Burnaby, BC, conductivity follows a linear relationship to chloride concentration. Chloride in mg/L=(0.3013 x SpCond - 16.095) |
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| 29 | silverhammer |
April 21, 2014 03:41
| over 10 years ago
Purpose of this wikiThis wiki is intended to provide short, legible descriptions of common water contaminants, with a no-nonsense rundown on what methods might be used to both assess and address the presence of these contaminants. We're aiming to pay special attention to the relative cost and technical expertise required for each method. For example, some of these contaminants might be readily addressed by simple, cheap home testing kits. Some of them might currently require expensive laboratory testing. For many of them, the EPA and others have published protocols for how to assess the level of these contaminants in a laboratory setting; we'd like to begin to collect links to these protocols, labeling them as "possibly DIY?" or "DIY: implausible", etc ... Suggested format for entries:
Please help us fill out this list with relevant info about important water contaminants ... GlyphosateWhy is it a problem? How does it enter the water supply?Glyphosate is a commonly used pesticide sold under trademarks such as Monsanto's 'Roundup'. that enters the water supply via ... How much is safe?Experts disagree on safe levels; the EPA has set a legally enforceable maximum contaminant level (MCL) for glyphosate of 700 ug/l in drinking water, which is 7,000 times higher than the MCL in Europe. How is it tested?Possible testing methods include: a) laboratory tests, for $200 - $300 (links to more info) b) spectroscopy (see Public Lab's Spectroscopy Kit) (links more info) ; c) conductivity (see Public Lab's Riffle) (links more info) d) paper chromatography tests (see the following four kits, available online) (links to more info) Method proposed to build a Roundup standard curve using the PublicLab spectrometer at 880nm here under "experiment 5": http://publiclab.org/wiki/pesticide-detection-methods-development What can be done about it?Links to more infohttp://www.organicconsumers.org/articles/article_29696.cfm Endocrine disruptorsMercuryArsenicLeadOil and Grease-TPH Volatiles -TPH Gasoline -TPH Diesel and Oil Nitrogen: Nitrates, Nitrite, Ammonia, & AmmoniumNitrates, Nitrite, Ammonia, & Ammonium are "fixed" forms of nitrogen available to living organisms, and represent different stages of nitrogen in the nitrogen cycle. Nitrogen is a major limiting nutrient in plant growth-- when nitrates occur in large quantities in water from fertilizers, manure, or sewage runoff, they can cause algal blooms that create dead zones. Nitrates have also been linked to increased risks of cancer, and complications with a number of diseases, including asthma. The EPA limits drinking water concentrations of Nitrates to 10mg/L or lower, however, health threats can occur even at those levels. Ammonia (NH3) and ammonium ion (NH4+) are related chemically by an acid / base reaction: NH3 + H+ <=> NH4+ The equilibrium between ammonia and ammonium is pH dependent, with the two species being at the same concentration only under fairly alkaline conditions, pH = 9.25. At neutral pH, the concentration of free NH3 is less than 1% that of NH4+. Since this is the case, the concentration of ammonia is usually not significant and can be determined from the concentration of ammonium and the pH. Assaying NitrogenThe wet lab Kjeldahl Method is often used to get the measurement TKN, or Total Kjeldahl Nitrogen. EPA Method 353.2 involves a cobalt catalyst and spectroscopy in the visible range. UV SpectroscopyIn Situ Underwater Spectroscopy (UV in the ocean): TSS, BOD, and Nitrate with a single 200nm-720nm spectrometer ON-LINE NITRATE MONITORING IN SEWERS USING UV/VIS SPECTROSCOPY F. Hofstaedter, T. Ertl, G. Langergraber, W. Lettl, A. Weingartne Potentiometric Measurements of Nitrate and Ammonium using Ion Selective ElectrodesIon selective electrodes (discussed here) can be used to conveniently measure ammonium and nitrate. These electrodes behave similarly to commonly used pH electrodes. The main difference between a pH electrode and an ion selective electrode (ISE) is that the former has a glass surface that is electrically polarized by protons and the latter has a membrane that is responsive to the ion in question. Like a pH electrode, an ion selective electrode responds to changes in analyte concentration by a measurable change in voltage. Ion selective electrodes can be measured with most pH meters. These electrodes can be purchased from a variety of sources (VWR, Fisher, etc) but are somewhat more expensive than pH electrodes. Vernier sells ammonium and nitrate sensitive electrodes (here) for $179 each. Road saltRoad salt is detrimental both to aquatic life and to plants. In Canada, it was classified as a toxic substance, but then, since so much was being used to keep roads safe, they did not carry through with measures to reduce it, only voluntary guidelines. Conductivity is a surrogate for chloride content. In Stoney Creek in Burnaby, BC, conductivity follows a linear relationship to chloride concentration. Chloride in mg/L=(0.3013 x SpCond - 16.095) |
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| 28 | acjames76 |
April 20, 2014 01:35
| over 10 years ago
Purpose of this wikiThis wiki is intended to provide short, legible descriptions of common water contaminants, with a no-nonsense rundown on what methods might be used to both assess and address the presence of these contaminants. We're aiming to pay special attention to the relative cost and technical expertise required for each method. For example, some of these contaminants might be readily addressed by simple, cheap home testing kits. Some of them might currently require expensive laboratory testing. For many of them, the EPA and others have published protocols for how to assess the level of these contaminants in a laboratory setting; we'd like to begin to collect links to these protocols, labeling them as "possibly DIY?" or "DIY: implausible", etc ... Suggested format for entries:
Please help us fill out this list with relevant info about important water contaminants ... GlyphosateWhy is it a problem? How does it enter the water supply?Glyphosate is a commonly used pesticide sold under trademarks such as Monsanto's 'Roundup'. that enters the water supply via ... How much is safe?Experts disagree on safe levels; the EPA has set a legally enforceable maximum contaminant level (MCL) for glyphosate of 700 ug/l in drinking water, which is 7,000 times higher than the MCL in Europe. How is it tested?Possible testing methods include: a) laboratory tests, for $200 - $300 (links to more info) b) spectroscopy (see Public Lab's Spectroscopy Kit) (links more info) ; c) conductivity (see Public Lab's Riffle) (links more info) d) paper chromatography tests (see the following four kits, available online) (links to more info) What can be done about it?Links to more infohttp://www.organicconsumers.org/articles/article_29696.cfm Endocrine disruptorsMercuryArsenicLeadOil and Grease-TPH Volatiles -TPH Gasoline -TPH Diesel and Oil Nitrogen: Nitrates, Nitrite, Ammonia, & AmmoniumNitrates, Nitrite, Ammonia, & Ammonium are "fixed" forms of nitrogen available to living organisms, and represent different stages of nitrogen in the nitrogen cycle. Nitrogen is a major limiting nutrient in plant growth-- when nitrates occur in large quantities in water from fertilizers, manure, or sewage runoff, they can cause algal blooms that create dead zones. Nitrates have also been linked to increased risks of cancer, and complications with a number of diseases, including asthma. The EPA limits drinking water concentrations of Nitrates to 10mg/L or lower, however, health threats can occur even at those levels. Ammonia (NH3) and ammonium ion (NH4+) are related chemically by an acid / base reaction: NH3 + H+ <=> NH4+ The equilibrium between ammonia and ammonium is pH dependent, with the two species being at the same concentration only under fairly alkaline conditions, pH = 9.25. At neutral pH, the concentration of free NH3 is less than 1% that of NH4+. Since this is the case, the concentration of ammonia is usually not significant and can be determined from the concentration of ammonium and the pH. Assaying NitrogenThe wet lab Kjeldahl Method is often used to get the measurement TKN, or Total Kjeldahl Nitrogen. EPA Method 353.2 involves a cobalt catalyst and spectroscopy in the visible range. UV SpectroscopyIn Situ Underwater Spectroscopy (UV in the ocean): TSS, BOD, and Nitrate with a single 200nm-720nm spectrometer ON-LINE NITRATE MONITORING IN SEWERS USING UV/VIS SPECTROSCOPY F. Hofstaedter, T. Ertl, G. Langergraber, W. Lettl, A. Weingartne Potentiometric Measurements of Nitrate and Ammonium using Ion Selective ElectrodesIon selective electrodes (discussed here) can be used to conveniently measure ammonium and nitrate. These electrodes behave similarly to commonly used pH electrodes. The main difference between a pH electrode and an ion selective electrode (ISE) is that the former has a glass surface that is electrically polarized by protons and the latter has a membrane that is responsive to the ion in question. Like a pH electrode, an ion selective electrode responds to changes in analyte concentration by a measurable change in voltage. Ion selective electrodes can be measured with most pH meters. These electrodes can be purchased from a variety of sources (VWR, Fisher, etc) but are somewhat more expensive than pH electrodes. Vernier sells ammonium and nitrate sensitive electrodes (here) for $179 each. Road saltRoad salt is detrimental both to aquatic life and to plants. In Canada, it was classified as a toxic substance, but then, since so much was being used to keep roads safe, they did not carry through with measures to reduce it, only voluntary guidelines. Conductivity is a surrogate for chloride content. In Stoney Creek in Burnaby, BC, conductivity follows a linear relationship to chloride concentration. Chloride in mg/L=(0.3013 x SpCond - 16.095) |
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| 27 | JSummers |
April 18, 2014 16:33
| over 10 years ago
Purpose of this wikiThis wiki is intended to provide short, legible descriptions of common water contaminants, with a no-nonsense rundown on what methods might be used to both assess and address the presence of these contaminants. We're aiming to pay special attention to the relative cost and technical expertise required for each method. For example, some of these contaminants might be readily addressed by simple, cheap home testing kits. Some of them might currently require expensive laboratory testing. For many of them, the EPA and others have published protocols for how to assess the level of these contaminants in a laboratory setting; we'd like to begin to collect links to these protocols, labeling them as "possibly DIY?" or "DIY: implausible", etc ... Suggested format for entries:
Please help us fill out this list with relevant info about important water contaminants ... GlyphosateWhy is it a problem? How does it enter the water supply?Glyphosate is a commonly used pesticide sold under trademarks such as Monsanto's 'Roundup'. that enters the water supply via ... How much is safe?Experts disagree on safe levels; the EPA has set a legally enforceable maximum contaminant level (MCL) for glyphosate of 700 ug/l in drinking water, which is 7,000 times higher than the MCL in Europe. How is it tested?Possible testing methods include: a) laboratory tests, for $200 - $300 (links to more info) b) spectroscopy (see Public Lab's Spectroscopy Kit) (links more info) ; c) conductivity (see Public Lab's Riffle) (links more info) d) paper chromatography tests (see the following four kits, available online) (links to more info) What can be done about it?Links to more infohttp://www.organicconsumers.org/articles/article_29696.cfm Endocrine disruptorsMercuryArsenicLeadOil and Grease-TPH Volatiles -TPH Gasoline -TPH Diesel and Oil Nitrogen: Nitrates, Nitrite, Ammonia, & AmmoniumNitrates, Nitrite, Ammonia, & Ammonium are "fixed" forms of nitrogen available to living organisms, and represent different stages of nitrogen in the nitrogen cycle. Nitrogen is a major limiting nutrient in plant growth-- when nitrates occur in large quantities in water from fertilizers, manure, or sewage runoff, they can cause algal blooms that create dead zones. Nitrates have also been linked to increased risks of cancer, and complications with a number of diseases, including asthma. The EPA limits drinking water concentrations of Nitrates to 10mg/L or lower, however, health threats can occur even at those levels. Ammonia (NH3) and ammonium ion (NH4+) are related chemically by an acid / base reaction: NH3 + H+ <=> NH4+ The equilibrium between ammonia and ammonium is pH dependent, with the two species being at the same concentration only under fairly alkaline conditions, pH = 9.25. At neutral pH, the concentration of free NH3 is less than 1% that of NH4+. Since this is the case, the concentration of ammonia is usually not significant and can be determined from the concentration of ammonium and the pH. Assaying NitrogenThe wet lab Kjeldahl Method is often used to get the measurement TKN, or Total Kjeldahl Nitrogen. EPA Method 353.2 involves a cobalt catalyst and spectroscopy in the visible range. UV SpectroscopyIn Situ Underwater Spectroscopy (UV in the ocean): TSS, BOD, and Nitrate with a single 200nm-720nm spectrometer ON-LINE NITRATE MONITORING IN SEWERS USING UV/VIS SPECTROSCOPY F. Hofstaedter, T. Ertl, G. Langergraber, W. Lettl, A. Weingartne Potentiometric Measurements of Nitrate and Ammonium using Ion Selective ElectrodesIon selective electrodes (discussed here) can be used to conveniently measure ammonium and nitrate. These electrodes behave similarly to commonly used pH electrodes. The main difference between a pH electrode and an ion selective electrode (ISE) is that the former has a glass surface that is electrically polarized by protons and the latter has a membrane that is responsive to the ion in question. Like a pH electrode, an ion selective electrode responds to changes in analyte concentration by a measurable change in voltage. Ion selective electrodes can be measured with most pH meters. These electrodes can be purchased from a variety of sources (VWR, Fisher, etc) but are somewhat more expensive than pH electrodes. Vernier sells ammonium and nitrate sensitive electrodes (here) for $179 each. |
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| 26 | mathew |
April 18, 2014 02:19
| over 10 years ago
Purpose of this wikiThis wiki is intended to provide short, legible descriptions of common water contaminants, with a no-nonsense rundown on what methods might be used to both assess and address the presence of these contaminants. We're aiming to pay special attention to the relative cost and technical expertise required for each method. For example, some of these contaminants might be readily addressed by simple, cheap home testing kits. Some of them might currently require expensive laboratory testing. For many of them, the EPA and others have published protocols for how to assess the level of these contaminants in a laboratory setting; we'd like to begin to collect links to these protocols, labeling them as "possibly DIY?" or "DIY: implausible", etc ... Suggested format for entries:
Please help us fill out this list with relevant info about important water contaminants ... GlyphosateWhy is it a problem? How does it enter the water supply?Glyphosate is a commonly used pesticide sold under trademarks such as Monsanto's 'Roundup'. that enters the water supply via ... How much is safe?Experts disagree on safe levels; the EPA has set a legally enforceable maximum contaminant level (MCL) for glyphosate of 700 ug/l in drinking water, which is 7,000 times higher than the MCL in Europe. How is it tested?Possible testing methods include: a) laboratory tests, for $200 - $300 (links to more info) b) spectroscopy (see Public Lab's Spectroscopy Kit) (links more info) ; c) conductivity (see Public Lab's Riffle) (links more info) d) paper chromatography tests (see the following four kits, available online) (links to more info) What can be done about it?Links to more infohttp://www.organicconsumers.org/articles/article_29696.cfm Endocrine disruptorsMercuryArsenicLeadOil and Grease-TPH Volatiles -TPH Gasoline -TPH Diesel and Oil Nitrogen: Nitrates, Nitrite, Ammonia, & AmmoniumNitrates, Nitrite, Ammonia, & Ammonium are "fixed" forms of nitrogen available to living organisms, and represent different stages of nitrogen in the nitrogen cycle. Nitrogen is a major limiting nutrient in plant growth-- when nitrates occur in large quantities in water from fertilizers, manure, or sewage runoff, they can cause algal blooms that create dead zones. Nitrates have also been linked to increased risks of cancer, and complications with a number of diseases, including asthma. The EPA limits drinking water concentrations of Nitrates to 10mg/L or lower, however, health threats can occur even at those levels. Assaying NitrogenThe wet lab Kjeldahl Method is often used to get the measurement TKN, or Total Kjeldahl Nitrogen. EPA Method 353.2 involves a cobalt catalyst and spectroscopy in the visible range. UV SpectroscopyIn Situ Underwater Spectroscopy (UV in the ocean): TSS, BOD, and Nitrate with a single 200nm-720nm spectrometer ON-LINE NITRATE MONITORING IN SEWERS USING UV/VIS SPECTROSCOPY F. Hofstaedter, T. Ertl, G. Langergraber, W. Lettl, A. Weingartne |
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| 25 | mathew |
April 18, 2014 02:16
| over 10 years ago
Purpose of this wikiThis wiki is intended to provide short, legible descriptions of common water contaminants, with a no-nonsense rundown on what methods might be used to both assess and address the presence of these contaminants. We're aiming to pay special attention to the relative cost and technical expertise required for each method. For example, some of these contaminants might be readily addressed by simple, cheap home testing kits. Some of them might currently require expensive laboratory testing. For many of them, the EPA and others have published protocols for how to assess the level of these contaminants in a laboratory setting; we'd like to begin to collect links to these protocols, labeling them as "possibly DIY?" or "DIY: implausible", etc ... Suggested format for entries:
Please help us fill out this list with relevant info about important water contaminants ... GlyphosateWhy is it a problem? How does it enter the water supply?Glyphosate is a commonly used pesticide sold under trademarks such as Monsanto's 'Roundup'. that enters the water supply via ... How much is safe?Experts disagree on safe levels; the EPA has set a legally enforceable maximum contaminant level (MCL) for glyphosate of 700 ug/l in drinking water, which is 7,000 times higher than the MCL in Europe. How is it tested?Possible testing methods include: a) laboratory tests, for $200 - $300 (links to more info) b) spectroscopy (see Public Lab's Spectroscopy Kit) (links more info) ; c) conductivity (see Public Lab's Riffle) (links more info) d) paper chromatography tests (see the following four kits, available online) (links to more info) What can be done about it?Links to more infohttp://www.organicconsumers.org/articles/article_29696.cfm Endocrine disruptorsMercuryArsenicLeadOil and Grease-TPH Volatiles -TPH Gasoline -TPH Diesel and Oil Nitrogen: Nitrates, Nitrite, Ammonia, & AmmoniumNitrates, Nitrite, Ammonia, & Ammonium are "fixed" forms of nitrogen available to living organisms, and represent different stages of nitrogen in the nitrogen cycle. Nitrogen is a major limiting nutrient in plant growth-- when nitrates occur in large quantities in water from fertilizers, manure, or sewage runoff, they can cause algal blooms that create dead zones. Nitrates have also been linked to increased risks of cancer, and complications with a number of diseases, including asthma. The EPA limits drinking water concentrations of Nitrates to 10mg/L or lower, however, health threats can occur even at those levels. Assaying NitrogenThe wet lab Kjeldahl Method is often used to get the measurement TKN, or Total Kjeldahl Nitrogen. EPA Method 353.2 involves a cobalt catalyst and spectroscopy in the visible range. UV SpectroscopyIn Situ Underwater Spectroscopy (UV in the ocean): TSS, BOD, and Nitrate with a single 200nm-720nm spectrometer ON-LINE NITRATE MONITORING IN SEWERS USING UV/VIS SPECTROSCOPY F. Hofstaedter, T. Ertl, G. Langergraber, W. Lettl, A. Weingartne |
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| 24 | eustatic |
April 17, 2014 00:20
| over 10 years ago
Purpose of this wikiThis wiki is intended to provide short, legible descriptions of common water contaminants, with a no-nonsense rundown on what methods might be used to both assess and address the presence of these contaminants. We're aiming to pay special attention to the relative cost and technical expertise required for each method. For example, some of these contaminants might be readily addressed by simple, cheap home testing kits. Some of them might currently require expensive laboratory testing. For many of them, the EPA and others have published protocols for how to assess the level of these contaminants in a laboratory setting; we'd like to begin to collect links to these protocols, labeling them as "possibly DIY?" or "DIY: implausible", etc ... Suggested format for entries:
Please help us fill out this list with relevant info about important water contaminants ... GlyphosateWhy is it a problem? How does it enter the water supply?Glyphosate is a commonly used pesticide sold under trademarks such as Monsanto's 'Roundup'. that enters the water supply via ... How much is safe?Experts disagree on safe levels; the EPA has set a legally enforceable maximum contaminant level (MCL) for glyphosate of 700 ug/l in drinking water, which is 7,000 times higher than the MCL in Europe. How is it tested?Possible testing methods include: a) laboratory tests, for $200 - $300 (links to more info) b) spectroscopy (see Public Lab's Spectroscopy Kit) (links more info) ; c) conductivity (see Public Lab's Riffle) (links more info) d) paper chromatography tests (see the following four kits, available online) (links to more info) What can be done about it?Links to more infohttp://www.organicconsumers.org/articles/article_29696.cfm Endocrine disruptorsMercuryArsenicLeadOil and Grease-TPH Volatiles -TPH Gasoline -TPH Diesel and Oil Ammonia |
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| 23 | bgamari |
April 16, 2014 23:08
| over 10 years ago
Purpose of this wikiThis wiki is intended to provide short, legible descriptions of common water contaminants, with a no-nonsense rundown on what methods might be used to both assess and address the presence of these contaminants. We're aiming to pay special attention to the relative cost and technical expertise required for each method. For example, some of these contaminants might be readily addressed by simple, cheap home testing kits. Some of them might currently require expensive laboratory testing. For many of them, the EPA and others have published protocols for how to assess the level of these contaminants in a laboratory setting; we'd like to begin to collect links to these protocols, labeling them as "possibly DIY?" or "DIY: implausible", etc ... Suggested format for entries:
Please help us fill out this list with relevant info about important water contaminants ... GlyphosateWhy is it a problem? How does it enter the water supply?Glyphosate is a commonly used pesticide sold under trademarks such as Monsanto's 'Roundup'. that enters the water supply via ... How much is safe?Experts disagree on safe levels; the EPA has set a legally enforceable maximum contaminant level (MCL) for glyphosate of 700 ug/l in drinking water, which is 7,000 times higher than the MCL in Europe. How is it tested?Possible testing methods include: a) laboratory tests, for $200 - $300 (links to more info) b) spectroscopy (see Public Lab's Spectroscopy Kit) (links more info) ; c) conductivity (see Public Lab's Riffle) (links more info) d) paper chromatography tests (see the following four kits, available online) (links to more info) What can be done about it?Links to more infohttp://www.organicconsumers.org/articles/article_29696.cfm Endocrine disruptorsMercuryArsenic |
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| 22 | donblair |
April 16, 2014 14:40
| over 10 years ago
Purpose of this wikiThis wiki is intended to provide short, legible descriptions of common water contaminants, with a no-nonsense rundown on what methods might be used to both assess and address the presence of these contaminants. We're aiming to pay special attention to the relative cost and technical expertise required for each method. For example, some of these contaminants might be readily addressed by simple, cheap home testing kits. Some of them might currently require expensive laboratory testing. For many of them, the EPA and others have published protocols for how to assess the level of these contaminants in a laboratory setting; we'd like to begin to collect links to these protocols, labeling them as "possibly DIY?" or "DIY: implausible", etc ... Suggested format for entries:
Please help us fill out this list with relevant info about important water contaminants ... GlyophosateWhy is it a problem? How does it enter the water supply?Glyophosate is a commonly used pesticide sold under trademarks such as Monsanto's 'Roundup'. that enters the water supply via ... How much is safe?Experts disagree on safe levels; the EPA has set a legally enforceable maximum contaminant level (MCL) for glyphosate of 700 ug/l in drinking water, which is 7,000 times higher than the MCL in Europe. How is it tested?Possible testing methods include: a) laboratory tests, for $200 - $300 (links to more info) b) spectroscopy (see Public Lab's Spectroscopy Kit) (links more info) ; c) conductivity (see Public Lab's Riffle) (links more info) d) paper chromatography tests (see the following four kits, available online) (links to more info) What can be done about it?Links to more infohttp://www.organicconsumers.org/articles/article_29696.cfm Endocrine disruptorsMercuryArsenic |
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| 21 | donblair |
April 16, 2014 14:10
| over 10 years ago
(NOTE: This research note is in-progress and not complete ... please feel free to add relevant info!) GlyophosateWhere does it come from?Glyophosate is a commonly used pesticide sold under trademarks such as Monsanto's 'Roundup'. that enters the water supply via ... How much is safe?Experts disagree on safe levels; the EPA has set a legally enforceable maximum contaminant level (MCL) for glyphosate of 700 ug/l in drinking water, which is 7,000 times higher than the MCL in Europe. How is it tested?Possible testing methods include: a) laboratory tests, for $200 - $300 (links to more info) b) spectroscopy (see Public Lab's Spectroscopy Kit) (links more info) ; c) conductivity (see Public Lab's Riffle) (links more info) d) paper chromatography tests (see the following four kits, available online) (links to more info) Referenceshttp://www.organicconsumers.org/articles/article_29696.cfm Endocrine disruptorsMercuryArsenic |
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| 20 | donblair |
April 15, 2014 20:09
| over 10 years ago
(NOTE: This research note is in-progress and not complete ... please feel free to add relevant info!) GlyophosateWhere does it come from?Glyophosate is a commonly used pesticide sold under trademarks such as Monsanto's 'Roundup'. that enters the water supply via ... How much is safe?Experts disagree on safe levels; the EPA has set a legally enforceable maximum contaminant level (MCL) for glyphosate of 700 ug/l in drinking water, which is 7,000 times higher than the MCL in Europe. How is it tested?Possible testing methods include: a) laboratory tests, for $200 - $300 (links to more info) b) spectroscopy (see Public Lab's Spectroscopy Kit) (links more info) ; c) conductivity (see Public Lab's Riffle) (links more info) d) paper chromatography tests (see the following four kits, available online) (links to more info) Referenceshttp://www.organicconsumers.org/articles/article_29696.cfm Endocrine disruptorsMercuryArsenic |
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