Sequential injection analysis system for the determination of arsenic by hydride generation atomic absorption spectrometry

A sequential injection system which consists of a syringe pump, a selector valve, a multi-port valve, a gas-liquid separator and a solenoid valve for the determination of arsenic by hydride generation atomic absorption spectrometry using tetrahydroborate as reductant was developed. The reduction time of sample with tetrahydoborate has increased by keeping the reactant in gas-liquid separator by using the solenoid valve. Various parameters affecting the performance of the sequential injection system were optimized, including reaction-time, carrier gas flow, sample volume, tetrahydroborate volume and concentration. Established sequential injection hydride generation technique was simple and automated operation. A sample throughput of 112/h was achieved with 400 μL samples with a precision of 2.0% RSD at 4 μg/L As (n = 10) and a detection limit of 0.09 μg/L. Good agreement with the certified values was obtained for the determination of arsenic in standard reference materials.