Abstract
The toxicological and biological roles of trace elements are reported highly dependent on their chemical forms and/or oxidation states. In the past decade, the understanding of the impact of various species of trace elements on biological and environmental systems has been remarkably advanced, due mainly to the significant improvement in the speciation techniques. In view of the need of pharmacokinetics studies, the metabolic and biotransportation information of arsenicals in target organs has been considered indispensable in adequately characterizing the effectiveness and impact of arsenic trioxide. Based on aforementioned requirements, an in vivo, in-situ and continuous analytical system was developed to monitor the dynamic variation of different arsenic metabolites in anesthetized rat.In our study, two miniaturized hyphenation techniques, named microdialysis-micro HPLC-ICP-MS and microdialysis-micro HPLC-HG-ICP-MS, were developed. To extract analyte species from target organs, Ringer’s solution was used to perfuse arsenicals from target organs at flow rate of 0.5 mL/min. An on-line injector (CMA 160) equipped with a 10-mL sample loop and a hydride generator was used to interface microdialysis probe, microbore-LC column and ICP-MS. Under the optimized conditions, the detection limits obtained with the proposed method can be as low as 0.37, 0.56, 1.42 and 1.88 ng/mL for As(III), DMA, MMA and As(V), respectively. The stability of this method can be controlled down to approximately 10 % after continuous operation up to 360 min, permitting to continuously monitor the variation of analyte arsenic species in anesthetized rat after the administration of arsenic trioxide. Based on the achieved analytical results, an in vivo, in-situ and continuous monitoring technique for the investigation of dynamic variation of trace arsenicals in anesthetized rat has been performed by this study. On behalf of the novelty of our proposed method, further characterization of the detoxification and metabolic mechanism of arsenic in various organisms has become possible.