Chementator: A portable analyzer for toxicity in humans
By Gerald Ondrey |
The standard way to test for toxicity in individuals who have been exposed to heavy metals is to take a blood sample and analyze it in the laboratory by plasma mass spectrometry, an expensive and time-consuming procedure. Now, a portable instrument that can do the same job in the field in 2 – 5 min, for one-tenth the cost, has been developed at Pacific Northwest National Laboratory (PNNL, Richland, Wash.; edlinks.chemengonline.com/7370-565).
The analyzer accepts a blood sample from a finger-prick, urine or saliva. The sample is injected into the instrument and flows over an electrode (the sensor), which adsorbs the metal from the sample. A voltage is applied to the electrode and generates a current from the metal. The type of metal is determined by the location of the peak current on the instrument’s display window, and its concentration is determined from the current intensity.
Individual sensors can detect one or more metals to within 1 – 2 ppb and can be easily exchanged in the instrument, says Wassana Yantasee, a PNNL scientist. So far, the laboratory has developed sensors for cadmium, copper, lead, mercury and silver. There are two sensor configurations, both of which work well, she says. Both consist of a self-assembled…