Investigation of speciation of arsenic in gas condensates by capillary gas chromatography with ICP-MS detection

On-line coupling of capillary GC with ICP-MS using the recently commercialized high-temperature interface was developed for the investigation of speciation of arsenic in gas condensates. Arsenic was present as a number of species, the two most abundant species being identified by retention time matching with standards such as triphenylarsine (Ph3As) and triethylarsine (Et3As). The calibration graph, obtained for Ph3As, was linear up to 100 ng mL(-1) and the detection limit was 0.05 pg (as As). The arsenic speciation was found to undergo a slight evolution as a function of sample storage time. Spiking with standards was found to change the equilibrium in the system.