Cool experiment, I have some glass test tubes if you want to give them a try?

OK, this guy is doing it with a $7,000 Ocean Optics Jaz spectrometer and several lasers: https://www.flickr.com/photos/bob_81667/6811951183/in/set-72157624831829718/

We should try to match his results!

And:

http://www.vernier.com/innovate/determination-of-chlorophyll-in-olive-oil/

You don't need a JAZ or lasers to see chlorophyll's fluorescence. LED's and a simple spectrometer can show it:

Here's a pic with one of Bob's spectra: https://www.flickr.com/photos/28617364@N04/6789117133/

Here's a pic of a spectrum taken with a $20 spectroscope. https://www.flickr.com/photos/28617364@N04/6831968677/

More pics of the experiments. https://www.flickr.com/photos/28617364@N04/sets/72157629930307517/

cool - well we're using webcams in our spectrometers, but the spectroscope you mention is paired with a camera that's taking a long exposure, right? It's harder to extract data automatically from a still camera, but the ability to do a long exposure is a big plus. My main problem at this point is that the amount of fluorescent light generated by the laser is not a lot for the small webcams we're using.

Typically we've been using halogen, tungsten, or other full-spectrum lights:

http://publiclaboratory.org/notes/spectrometer

but it's much easier to separate the signal from the source light with a laser, so I was interested to try.

Personally i'm not trying to measure chlorophyll but just doing tests and eventually trying to detect polyaromatic hydrocarbons (PAHs) from oil spill contamination. So this is kind of a stepping stone, but it was neat to see some high-end data to compare to.

Thanks!

It looks like you need a little rectangular glass container for the olive oil, like a tiny aquarium. Then the laser can shine right along the inside of the glass and all the oil along the glass will fluoresce. Then use a slit aligned with the laser beam so only the fluorescing oil can be seen. Align that slit with the spectrometer slit and only light from the fluorescence will enter the spectrometer. A longer exposure sure would be helpful.

($20 each) http://www.opticsplanet.net/unico-glass-square-spectrophotometer-cuvette-10mm-pathlength-3-5ml-capacity-vis-only.html

or for fancy people who want extremely good mid-infrared transparency: ($171 each) http://www.opticsplanet.net/unico-square-cuvettes-quartz-2x2-5-mm-window-s-90-359q.html

Bob seems to have used glass jam jars or tumblers. I think i'll raid the supermarket before spending on "real" lab equipment.

Here's a much much nicer spectrum in "a little rectangular glass container" just as Chris suggested. I still can't get a strong enough light that the spectrometer detects it. I'll keep trying. Also looking for a sample of heavier oil, like motor oil, to test. Then i'll try some samples from the Gulf oil spill!

following

need a source for those little jars. somewhere

I got them at American Science and Surplus: http://sciplus.com/p/WHITCAP-BOTTLE_48212

But now we're thinking of this bulk buy of cuvettes, that may be a good standard for everyone to adopt. Let's try to move forward on that.

Would you be able to add a section on sample containers on the spectral analysis wiki page?