Hydride Generation Interface for Speciation Analysis Coupling Capillary Electrophoresis to Inductively Coupled Plasma Mass Spectrometry

Recent trends in CE of inorganic ions: From individual to multiple elemental species analysis

The major methodological developments in CE related to inorganic analysis are overviewed. This is an update to a previous review article by the author (Timerbaev, A. R., Electrophoresis 2004, 25, 4008-4031) and it covers the review work and innovative research papers published between January 2004 and the first part of 2006. As was underlined in that review, a growing interest of analytical community in providing elemental speciation information found a sound response of the CE method developers. Presently, almost every second research paper in the field of interest deals with element species analysis, the use of inductively coupled plasma MS detection and biochemical applications being the topics of utmost research efforts. On the other hand, advances in general methodology traditionally centered on a CE system modernization for improvements in sensitivity and separation selectivity have attracted less attention over the review period. While there is no indication that inorganic ion applications would surpass by the developmental rate the more matured analysis of organic analytes, CE can now be seen as an analytical technique to be before long customary in a number of inorganic analysis arenas.

Speciation analysis of arsenic and selenium compounds in environmental and biological samples by ion chromatography-inductively coupled plasma dynamic reaction cell mass spectrometer

An inductively coupled plasma mass spectrometer (ICP-MS) was used as an ion chromatographic (IC) detector for the speciation analysis of arsenic and selenium. The arsenic and selenium species studied included arsenite [As(III)], arsenate [As(V)], monomethylarsonic acid (MMA), dimethylarsinic acid (DMA), arsenobetaine (AsB), selenite [Se(IV)] and selenate [Se(VI)]. Gradient elution using (NH4)2CO3 and methanol at pH 9 allowed the chromatographic separation of all species in less than 12 min. Effluents from the IC column were delivered to the nebulization system of ICP-DRC-MS for the determination of arsenic and selenium. The potentially interfering 38Ar 40Ar+ and 40Ar 40Ar+ at the selenium masses m/z 78 and 80 were reduced in intensity by approximately 3 orders of magnitude by using 0.6 mL min(-1) CH4 as reactive cell gas in the DRC while an Rpq value of 0.3 was used. Meanwhile, arsenic was determined as the adduct ion 75As 12CHH+ at m/z 89, which is more sensitive than 75As. The limits of detection for arsenic and selenium were in the range of 0.002-0.01 ng mL(-1) and 0.01-0.02 ng mL(-1), respectively, based on peak height. The relative standard deviation of the peak areas for five injections of 5 ng mL(-1) As and Se mixture was in the range of 2-4%. The concentrations of arsenic and selenium species have been determined in urine samples collected locally. The major As and Se species in urines were AsB, DMA and probably selenosugar at concentration of 20-40, 15-19 and 17-31 ng mL(-1), respectively. The recoveries were in the range of 94-105% for all the determinations. This method has also been applied to determine various arsenic compounds in two fish samples. In this study, a simple and rapid microwave-assisted extraction method was used for the extraction of arsenic compounds from fish. The arsenic species were quantitatively leached with an 80% v/v methanol solution in a focused microwave field during a period of 5 min.

Speciation of inorganic selenium using capillary electrophoresis–inductively coupled plasma-atomic emission spectrometry with on-line hydride generation

A novel and simple hydride generator has been developed. The hydride generator has good stability and high gas liquid separation efficiency. The generator serves as an interface of capillary electrophoresis (CE) and inductively coupled plasma atomic emission spectrometry (ICP-AES). This device eliminates the nebulization step and overcomes the common problem of suction flow resulting from the use of nebulization gas in ICP. Selenium compounds that were separated by CE were converted into the corresponding volatile hydrides, followed by ICP-AES measurement. The effects of the concentration of the hydride generating reagents (HCl and NaBH4), the carrier gas flow rate, and heavy metal interference on Se emission intensity were discussed. The relative standard deviations (RSDs) of peak area, based on six determinations of 50 ng mL(-1) standard of Se(IV) and Se(VI), were 1.5% and 1.8%, respectively. The detection limits (3sigma) of peak area were 2.1 ng mL(-1) and 2.3 ng mL(-1) for Se(IV) and Se(VI), respectively. Speciation analysis of inorganic Se(IV) and Se(IV) species using the HG-CE-ICP-AES system was demonstrated in tap and river water samples.

Recent advances in capillary electrophoresis and capillary electrochromatography of pollutants

Recent advances in the CE and CEC separation, detection, and sample preparation methodologies applied to the determination of a variety of compounds having current or potential environmental relevance have been overviewed. The reviewed literature has illustrated the wide range of CE applications, indicating the continuing interest in CE and CEC in the environmental field.