Evaluation of Various Hybrid Analytical Techniques for Resolving Arsenic Species in Soils and Natural Waters from Korea

The importance of arsenic detection in terms of different chemical species is becoming nowadays environmental concern. The analytical technique for true separation of different arsenic species has been challenging in many environmental samples. Achieving correct analytical results and resolving the lowest detection limit of each species is also desirable. However arsenic species can be transformed rapidly by slight changes in redox condition during experimental manipulation. It has been documented by USEPA for standard analytical technique for arsenic from many samples. However the previously documented techniques concerns only total arsenic concentration. Many analytical techniques for analyzing arsenic species are being suggested and hybrid analytical technique is regarded as essential method to resolve arsenic species. In this study, various hybrid techniques using ICP were tested to separate arsenic species in different type of samples. The anion exchange cartridge (Accell Plus QMA, Waters) or column (PRP X-100, Hamilton) in the part for separation and (HG)-ICP-AES or (HG)-ICP-MS in the part for detection coupled. Hydride generation (HG) method is used to improve detection limits. In addition, it can prevent from interference of 75 ArCl which is a significant problem of ICP-MS application to arsenic analysis. Anion exchange cartridge is only applicable in separation of inorganic arsenic species, typically available to acid mine drainage and groundwater samples in which arsenic mainly exists inorganic form. LC-(HG)-ICP-MS techenique is profitable to natural surface water samples which have a small fraction of various arsenic species. The leachate from soil samples should be treated carefully because high content of transition metals cause interferences. If there were a probability of leaching considerable amount of organic matter and transition metals during soil extraction, HG technique with purification procedure and use of masking agent must be applied to complete analysis of each arsenic species.