Abstract
A method for the measurement of parts per billion levels of total arsenic in urine and blood is described. Samples are wet ashed with a mixture of HNO3, HCIO4, and H2SO4 acids. Ashed materials are subjected to a reductillationTM procedure to reduce As (V) to As (III) and to separate arsenic from the sample matrix. Collected arsenic is then quantitated by anodic stripping voltammetry (ASV) at a gold film electrode. ASV analysis time is only 2 minutes. By simultaneous reductillation of 4 samples, ppb arsenic determinations can be accomplished at a rate of about 12 per hour. The method is as accurate, precise and reliable at the nanogram level as the more universally accepted colorimetric techinques are at the microgram and milligram levels. For replicate analysis of real samples, method precision ranged from ± 1.4 ppb at the 5 ppb level to ± 0.96 ppb at the 25 ppb level. Accuracy is estimated at ± 6% over the range 5 to 500 ppb arsenic.