Speciation analysis of arsenic in Mya arenaria Linnaeus and Shrimp with capillary electrophoresis-inductively coupled plasma mass spectrometry

• Published in: Talanta (Oxford) 2009-04, Vol.78 (2), p.471-476
• Main Authors: Yang, GuiDi, Xu, JinHua, Zheng, JinPing, Xu, XueQin, Wang, Wei, Xu, LiangJun, Chen, GuoNan, Fu, FengFu
• Format: Article
• Language: English
• Subjects: Analytical chemistry; Animals; Arsenic; Arsenic - analysis; Arsenic - chemistry; CE-ICP-MS; Chemistry; Chromatographic methods and physical methods associated with chromatography; Electrophoresis, Capillary - methods; Exact sciences and technology; Food Contamination - analysis; Mass Spectrometry - methods; Microwaves; Mya; Mya arenaria Linnaeus; Other chromatographic methods; Penaeidae; Shellfish - analysis; Shrimps; Speciation analysis; Spectrometric and optical methods
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2008.11.040

An improved sheath-flow interface used to couple capillary electrophoresis (CE) with inductively coupled plasma mass spectrometry (ICP-MS) and a microwave-assisted extraction used to extract each arsenic species in seafood were developed in this work. The improved sheath-flow interface completely avoids laminar flow in CE capillary caused by the suction from ICP-MS, makes electric supply more stable in CE, and transports analyte solution to ICP-MS easily and more efficiently. CE-ICP-MS coupled with our interface have two quantitative analysis modes: continuous sample-introduction mode and collective sample-introduction mode. The collective sample-introduction technique greatly reduced the dead volume of interface to approximately zero, obviously avoided the excessive dilution of analyte, and eventually led to a much lower detection limit and a much better electrophoretic resolution. This was demonstrated by the better symmetry and narrow peak widths (10–12 s) and much lower detection limits (0.030–0.042 μg/L) of four species of arsenic determined with collective sample-introduction mode. With the help of this improved sheath-flow interface and the microwave-assisted extraction, we have successfully separated and determined four arsenic species, As(III), As(V), monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) in dried Mya arenaria Linnaeus and Shrimp samples using CE-ICP-MS within 10 min with a relative standard deviation of 2–4% (peak areas, n = 6) and a recovery of 96–105%.