A pocket sushi probe?

Anne L. Fischer, Senior Editor, anne.fischer@laurin.com

Mercury is found in all sorts of things. From the fish we may eat to the fillings in our teeth, understanding just how much mercury is involved is important because of the potential health risks.

To address this problem, a group at the University of Pittsburgh School of Arts and Sciences is developing a portable mercury detector that you may someday be able to take with you to the sushi bar. The device uses a fluorescent substance that glows bright green when it comes into contact with oxidized mercury – the brighter it is, the higher the level. According to lead researcher and chemistry professor Kazunori Koide, “The fluorescence intensity is linearly proportional to the concentration of Hg.” It takes 10 to 30 minutes to test fish and 30 to 60 minutes to check out your dental fillings.

Safety issue

It works because mercury ions react with hydrocarbons called alkynes. The alkyne creates a fluorescent molecule that’s converted into a ketone. One advantage of this detection method over others is that mercury samples must be oxidized to make the samples safe to handle – and this method handles the oxidized samples well, while other fluorescence detectors do not.

The researchers tested both fish and dental fillings. They put a piece of salmon in water mixed with a solution similar to chlorine bleach. When they added the alkyne solution, the mixture glowed bright green. To test a tooth, they first rinsed the mouth with an aqueous cysteine solution and then pressed a cloth to a tooth with a filling for one minute, and it glowed green.

The detector also can be used in dentists’ offices to test the level of mercury in amalgam disposal (wastewater). According to Koide, “You can just wipe a sink and put the paper towel in a vial containing our mercury indicator.”

Unfortunately for those sushi eaters among us, it’s not likely we’ll see a mercury detector in our pocket anytime soon. As Koide pointed out, “The cost of a handheld fluorometer ($2000) may be too much for individuals. We may have to develop a slightly different approach.”