There are a few commonly available products that you can use to measure fluorescence with the SpectroVis Plus. The easiest is extra virgin olive oil. You don’t need to prepare the sample in any way. Pour about 3 mL of olive oil into a cuvette and you’re ready to collect fluorescence data. The chlorophyll in EV olive oil fluoresces nicely when it is excited with the 405 nm LED in the SpectroVis Plus. You can also look down into the cuvette and see the fluorescing.
Follow the steps below to set up the SpectroVis Plus with a computer and Logger Pro 3 to collect fluorescence data for a sample of extra virgin olive oil.
1) Open the Experiment menu and choose Set Up Sensors -> Spectrometer. A dialog box will appear.
2) Change the Sample Time to 160 ms and change the Samples to Average to 3.
3) Click the multicolored button in the upper right of the dialog box. A list of options will appear. Click Fluorescence 405 nm.
4) Close the dialog box.
5) Place a cuvette, about 3/4 full with extra virgin olive oil, in the SpectroVis Plus. NOTE: It doesnâ€™t matter how you orient the cuvette. The grooved sides of the cuvette donâ€™t pose a significant interference in this case. Click Collect and click Stop when a suitable plot appears on the graph.
Follow these steps to set up the SpectroVis Plus with a LabQuest to collect fluorescence data for a sample of extra virgin olive oil:
1) On the meter screen, tap on the reddish-orange meter box. Choose Change Units -> Fluorescence 405 nm.
2) Tap the gray Mode box to view the Data Collection screen. Change the Sample Time to 160 ms and change the Samples to Average to 3. Tap OK.
3) Place a cuvette, about 3/4 full with extra virgin olive oil, in the SpectroVis Plus. NOTE: It doesnâ€™t matter how you orient the cuvette. The grooved sides of the cuvette donâ€™t pose a significant interference in this case. Start the data collection and stop data collection when a suitable plot appears on the graph.
Other Common Substances:
A) You can extract the ink from a yellow or green highlighter pen and measure its fluorescence. This can be a bit messy. You need some isopropanol (rubbing alcohol) to extract the ink. Place the tip of the pen in a few mL of isopropanol until the liquid has a distinct color from the pen. Alternately, you can carefully pull the pen apart, remove the ink reservoir (it will most likely be a felt-like cylinder), and soak the reservoir in about 10 mL of isopropanol. Use the 405 nm excitation LED. When you set up the data collection in Logger Pro 3 or LabQuest, set the Sample Time at 100 ms, but you may need to increase or decrease the sample time depending on the height of the peak on your graph.
B) Commercial automobile radiator coolant normally contains fluorescein. However, the coolant needs to be diluted. Try mixing equal volumes of the coolant and water. You may have to dilute the product further if the fluorescence readings are too high. Use the 505 nm excitation LED. Set the Sample Time at 50 ms, and adjust it from there depending on the results.
C) Vitamin B2 (Riboflavin) fluoresces at both the 405 nm and the 505nm excitation LEDs. We suggest using over the counter 100 mg B2 supplement capsules. Add the capsule contents to a mixture of 50 mL of vinegar + 200 mL of distilled water. Alternately, you can mix the capsule contents with 250 mL of club soda. There will be some undissolved solids. Let the mixture settle or filter it. Set the Sample Time at 100 ms, and adjust it from there depending on the results.
D) Turmeric is another compound that you can buy from the store that should exhibit decent fluorescence. Mix 1/4-1/8 teaspoon of turmeric in 100 ml of rubbing alcohol. Mix the solution for a few minutes and then filter. Dilute the solution so that the absorbance of the solution is below 1. The solution should exhibit fluorescence using the 405 nm excitation LED. You will need to increase the sample time to 600-1000 ms to get decent data.