Concentrations and speciation of arsenic in tree moss extracts produced by different technologies

In order to study the effects of different extraction technologies on the arsenic measured in tree moss extracts,ICP-MS and RP-HPLC-ICP-MS were used to analyze the concentrations and species of arsenic.The results showed that:1) The conventional procedures of alcohol re-extraction and freezing separation decreased the arsenic concentration by 37% to 49%.2) AsC(Arsenocholine) was not detected in all the tree moss extracts extracted by different solvents.As(Ⅲ) and DMA(Dimethylarsenic acid) were the main arsenic species in the tree moss extracts extracted by alcohol,alcohol/propylene glycol and sub-critical butane,whileas As(Ⅴ) and DMA were the main species in those extracted by water.3) After alcohol re-extraction and/or freezing separation,the proportions of arsenic species did not changed greatly,however the total arsenic decreased in the tree moss extracts extracted by alcohol and alcohol/propylene glycol.The concentration of As(Ⅴ) decreased much more than that of As(Ⅲ) and DMA in tree moss extracts extracted by water,which indicated that the solubility of As(Ⅲ) and DMA in alcohol was higher than that of As(Ⅴ).