INSITU HYDRIDE GENERATION PRECONCENTRATION OF ARSENIC IN A GRAPHITE-FURNACE WITH SAMPLE VAPORIZATION INTO A MICROWAVE INDUCED PLASMA FOR EMISSION-SPECTROMETRY

A graphite furnace is used for in situ concentration of arsine, generated from aqueous samples, and subsequent vaporization of the sequestered arsenic into an atmospheric pressure helium microwave induced plasma for excitation. Calibration is achieved with aqueous standards. An absolute detection limit (3σ) of 120pg with a corresponding concentration detection limit of 12pg/ml (based on a 10ml test sample) is obtained. The relative standard deviations at the 1 ng/ml level are of the order of 6%. The accuracy was assessed by analyses of NRCC CASS-1, a nearshore marine reference water. © 1990.