Determination of 4 arsenic spceciations in seawater by ion chromatography-hydride generation-atomic fluorescence spectrometry

A method of simultaneously detecting 4kinds of different arsenic speciations,arsenite(As(III)),monomethylarsonic acid(MMA),dimethylasinic acid(DMA)and arsenate(As(V)),in seawater is developed by ion chromatography-hydride generation-atomic fluorescence spectrometry(IC-HG-AFS).Experimental conditions including mobile phase,carrying hydrochloric acid,reducing agent,carrier gas flow rate are optimized,and the influences of coexisting ions are investigated.For eliminating interference of Cl-in seawater matrix,the silver SPE columns is used.These species can be successfully separated in 12 min by the method.The detection limits of As(III),DMA,MMA,and As(V)are 1.00,1.68,1.33 and 2.34μg/L,respectively.Good linearities of As(III),MMA,DMA are obtained in the range of 5-250μg/L,and As(V)is obtained in the range of 10-250μg/L.The relative standard deviations is 1.0%-8.8%,and the recovery values are between77.8%and 96.3%.