After working with Chris to collect sediment samples from the Gowanus Canal, we tried shining a strong UV light through these two samples of olive oil (on the left) and BP oil residue (on the right, soaked in mineral oil). Both fluoresced strongly and we took this cool photo of it. Since we've been worried that the laser fluorescence we got in the same samples was not strong enough to be recorded by our spectrometers, maybe this technique will be a better bet. I hope to try taking a spectrum of this fluorescence today.
Here is the older laser fluorescence test: