ATHENS, Ohio -- A new technique that detects toxins in water in less than 10 minutes could lead to faster identification of harmful substances in the nation's water supplies, according to an Ohio University scientist who developed the method.
The technique applies a principle similar to that used in drug testing: samples are screened for the presence of a suspicious substance and only those that test positive are sent for further analysis.
Until now, there have been few screening methods for use by companies and environmental agencies charged with monitoring the nation's water supplies. Accurate water sampling of a large water system such as a river may require testing of as many as 100 samples from different locations in the river. Currently, each sample receives a full analysis, taking several hours per sample to complete.
"The problem with doing a full analysis on every sample is that you can spend hours analyzing a sample only to find out that it's below Environmental Protection Agency limits," said Anthony Andrews, an assistant professor of chemistry at Ohio University. "With our method, you won't get an exact result of the type or amount of contaminants in the water sample, but you'll know whether the sample is contaminated above or below EPA limits."
The method created by Andrews and former chemistry graduate student Glen Jackson can detect toxins at a level of just one-billionth of a gram per liter of water, well below current EPA standards, Andrews said.
The idea behind their technique may be simple, but the application is a
bit complex. A fiber coated with a special chemical layer is dipped into a water
sample. Any toxic molecules in the sample will be drawn to the chemical layer,
preferring it over water. The molecule-covered fiber is placed in a gas
chromatograph for separation. The injection port in the chromatograph is heated
to about 250 degrees Celsius, which drives the molecul
Contact: Anthony Andrews