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Technical Briefs |
1
Ecossensors Ltd., 74 Sunderland Rd., Sandy Bedfordshire SG19 1QY, UK and
2
Regional Lab. for Toxicol., City Hosp., Birmingham B18 7QH, UK,
3
present address;
a address for
correspondence: Inverness Medical Ltd., Beechwood Park North, Inverness IV2 3ED, UK, fax 44-1463-724601
In recent years concern over the adverse effects of low concentrations of lead on children has increased. In 1991, the CDC reduced the acceptable blood lead concentration from 250 µg/L to 100 µg/L and recommended screening of all American children <6 years old for lead poisoning (1). Graphite furnace atomic absorption spectroscopy is the most common method of measuring lead in blood, but the CDC has encouraged the development of other methods that could be used for mass population screening or near-patient testing. Such methods should be portable, cheap, and easier to use than graphite furnace atomic absorption spectroscopy as recommended by CDC Program Announcement 269, 1992.
The electrochemical technique of stripping voltametry at a mercury electrode has also been used for blood lead analysis. Commercially available instruments based on this method have been used widely but have insufficient accuracy and precision for measuring lead at low concentrations (2). Recently, improvements have been made in the electrochemical measurement of blood lead. Ostapczuk (3) and Jagner et al. (4) obtained good accuracy and precision at low concentrations by potentiometric stripping analysis. They used a mercury-coated graphite electrode that must be cleaned between each analysis, and their testing procedure required stirring of the acidified blood solution.
An approach to stripping analysis that simplifies the testing is the
use of disposable electrodes, which can be used once and then thrown
away. Microarray electrodes have properties that make them especially
suitable for this application. They have high current densities in
unstirred solution, have a high signal-to-background
Acknowledgments
References
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