Arsenic speciation by high performance liquid chromatography inductively coupled plasma mass spectrometry and capillary electrophoresis inductively coupled plasma mass spectrometry.

摘要

Arsenic contamination has been a global problem. Thousands of people suffer from chronic toxicity effects from the surrounding arsenic contaminated soil, ground water, and various foods. Identification and quantification of individual arsenic forms are important to appropriately measure the arsenic toxicity, environmental impact, and health risk related to arsenic exposure. Coupling either capillary electrophoresis (CE) or high performance liquid chromatography (HPLC) to inductively coupled plasma mass spectrometry (ICP-MS) is a powerful technique for trace elemental speciation analysis in various sample matrices. This hyphenated technique combines the high separation efficiency of CE and HPLC with the high elemental sensitivity and selectivity of ICPMS. In addition, HPLC is more suitable to couple with ICP-MS due to the compatible liquid flow rate of HPLC.; A modified concentric Meinhard nebulizer and interface were developed and used for coupling CE with ICP-MS. This interface is inexpensive, easy to handle, and universally applicable. The parameters that influence both separation efficiency and the detection limit were investigated.; An ion-pair reverse phase HPLC-ICP-MS method of separation and determination of arsenite (As(III)), dimethyl arsenic acid (DMA), monomethyl arsenic (MMA), and arsenate (As(V)) was studied. The separation was performed on a C18 column with hexadecyltrimethyl ammonium bromide (CTAB), ammonium phosphate buffer and methanol as mobile phase. This HPLC-ICP-MS method was validated by determining the arsenic species in urine standard reference material (SRM) 2670 and applied to Chinese brake fern, an arsenic hyperaccumulating plant. The speciation information can help to better understand the mechanisms of arsenic accumulation, translocation and detoxification in Chinese brake fern.