Arsenic determination in saline waters utilizing a tubular membrane as a gas–liquid separator for hydride generation inductively coupled plasma mass spectrometry
Abstract
A tubular silicone rubber membrane is evaluated as a gas-liquid separator for the determination of arsenic in saline waters via HG-ICP-MS. The system was optimized in terms of NaBH4 and HCl concentrations. The intermediate gas and carrier gas were optimized in terms of sensitivity and stability. The pre-reduction of AsV in standard solutions and reference materials was investigated using KI and KI plus ascorbic acid sample treatments. The KI plus ascorbic acid treatment produced a similar response for AsIII and AsV independent of the matrix. The KI plus ascorbic acid treated samples could be held for 21 days without significant response changes. The detection limit was 92 pg based on 7 replicate injections of a 400 pg standard. The overall system was evaluated by analysing two reference materials, NASS-4 and SLEW-2. Precision and recovery data were collected on three estuarine samples.