A simple and fast detection technique for arsenic speciation based on high-efficiency photooxidation and gas-phase chemiluminescence detection

摘要

High-efficiency photooxidation (HEPO) and gas phase chemiluminescence detection (CL) combined with high-performance liquid chromatography [HPLC) and hydride generation were developed for speciation of As(Ill), As(V), monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA). After chromatography separation, the arsenic species were passed through HEPO which performed efficient photooxidation and converted MMA and DMA to As(V) in several seconds. Then the reaction of ozone and arsine upon hydride generation produced a CL signal as the analytical parameter. The total analytical process was completed within 10 min. The effects of operational parameters such as the concentrations of hydrochloric acid and NaBH4 solution, carrier gas flow and air gas flow for ozone generation were investigated. Detection limits were 3.7, 10.3, 10.2 and 10.0 mu g/L for As(III), As(V), MMA and DMA, respectively. The recoveries of the four arsenic species in human urine sample ranged from 87 to 94%.