SCREEN-PRINTED ELECTRODES FOR STRIPPING MEASUREMENTS OF TRACE MERCURY

Screen-printed carbon-strip electrodes, coated with a thin gold film, are used for highly sensitive potentiometric stripping measurements of trace levels of mercury. The stripping response toward mercury at these inexpensive and disposable electrodes compares favorably with that common at conventional gold electrodes. Various experimental variables have been optimized to yield low detection limits (e.g., 0.5 mug 1-1 mercury for 4 min deposition) and good precision (e.g., R.S.D. of 2.5% for 20 repetitive measurements of 25 mug 1-1 mercury). Applicability to trace measurements of alkyl mercury and selenium is also demonstrated. Such adaptation of screen-printing technology for the development of reliable sensors for trace mercury should benefit numerous field applications.