Collection of Unknown Samples I decided to test paved areas showing residues from cars. I did that in areas near a coastal town of Boquerón, PR. 4 samples were collected, one of them a blank from pavement that did not show traces of oil. See Map.
I used Q-tips and a small amount of mineral oil (MO) for human consumption (no additives on the label). I added ca. 1mL of the MO to the residues on the pavement and recovered as much as possible of it swabbing the Q-tip and squeezing the cotton on the inner surface of the vial.
Different levels of color were recovered and basically none in the pavement blank. Mineral oil was added to all samples to achieve a similar volume.
SINCE FLUOROMETRY IS VERY SENSITIVE TO TURBIDITY AND PARTICLES, I WILL WAIT FOR A FEW DAYS BEFORE ANALYSIS. IF IT DOES NOT WORK, THEN SOME SORT OF SIMPLE FILTRATION/CENTRIFUGACION METHODS MIGHT BE NEEDED. THE ADDITION OF DEHYDRATING SALTS TO REMOVE WATER FROM SOLUTION AND DECREASE TURBIDITY.