Development of a Chemical Analysis for Ultratrace Arsenic in Water

摘要

Arsenic is one of the most toxic elements known to man. The presence of arsenic at the 0.01 g/ml level (0.01 ppm or 10 ppb) is considered undesirable for drinking water. The water quality laboratory, however, is incapable of the detection of arsenic at these levels. Thus arsenic is seldom monitored and rarely part of a routine and comprehensive program of the measurement of water quality. A unique enzymatic method has been developed for the determination of As(V) in natural waters. The method uses arsenic to catalyze a chemical reaction which produces a fluorescent species. The method has a detection limit of 8 micrograms/ml. A detailed study of the mechanism and magnitude of interferences has been performed. The results indicate that only Fe(+3) has the capability of causing erroneous results. This problem is avoided by masking with citrate.