Arsenic-specific detector

Francesconi, K.A., P. Micks, R.A. Stockton, and K.J. Irgolic. 1985. Quantitative determination of arsenobe-taine, the major water-soluble arsenical in three species of crab, using high pressure liquid chromatography and an inductively coupled argon plasma emission spectrometer as the arsenic-specific detector. Chemosphere 14 1443-1453. 

Plasma Emission Spectrometer as the Arsenic-Specific Detector. Chemosphere, 14, 1443. 

M Slekovec, W Goessler, KJ Irgolic. Inorganic and organic arsenic compounds in Slovenian mushrooms Comparison of arsenic specific detectors for liquid chromatography. Chem Spec Bioavailab 11 115-123, 1999. 

Concentrations of total arsenic in soil and water samples contaminated with old Arsenical Munitions are not very useful to characterize the potential risks. Knowledge of which arsenic compounds are present in such samples is absolutely necessary to define toxicity. The identification of arsenic compounds requires a separation step combined with a detection step. For separation, gas chromatography and high performance liquid chromatography are widely used. Atomic absorption spectrometers, inductively coupled plasma optical emission spectrometers, and inductively coupled plasma mass spectrometers may serve as arsenic-specific detectors. 

Financial support for the work on arsenic-specific detectors and for the preparation of this publication by the Robert A. Welch Foundation of Houston, Texas is gratefully acknowledged. 

The compounds MMA, DMA, and TMAO are reduced in acidic aqueous media by borohydride solutions to methylarsine (MeAsH2, bp 2°C), dimethylarsine (Me2AsH, bp 35°C), and trimethylarsine (Me3As, bp 55°C), respectively. These products are useful derivatives for speciation analysis of arsenic because they are readily separated from complex sample matrices and may be further separated from each other by distillation (41) or by gas chromatography (42) prior to their determination by element-specific detectors. Consequently, arsine generation techniques are the most commonly used methods for determining MMA, DMA, and TMAO in marine samples. 

T. Guerin, A. Astruc, M. Astruc, Speciation of arsenic and selenium compounds by HOLC hyphenated to specific detectors a review of the main separation techniques,... 

Persson and Irgum determined sub-p.p.m. concentrations of DMAA in seawater by electrothermal atomic absorption spectrometry. Graphite-furnace atomic absorption spectrometry was used as a sensitive and specific detector for arsenic. The technique allowed DMAA to be determined in a sample (20 ml) containing a 10 -fold excess of inorganic arsenic with a detection limit of 0.02ng As ml ... 

A set of guidelines for the separation of arsenic compounds using ion-exchange chromatography and ICP-MS as element-specific detector has been published (58). 

There is still a lot of work to do to make CZE a robust method for the determination of arsenic compounds in environmental samples. The proposed methods are too matrix sensitive and the difficulties of connecting CZE to element-specific detectors, such as ICP-MS, are not yet solved. At the moment, liquid chromatography in connection with element-specific detectors is certainly favored over CZE. 

Among the detectors discussed thus far, ICP-MS is certainly not the cheapest one. The advantage of ICP-MS lies in its multielement capabilities, excellent detection limits, and wide linear range. Moreover, low detection limits are not restricted to the hydride-forming arsenic compounds. The application of ICP-MS as an element-specific detector changed the knowledge about arsenic compounds... 

The identification of arsenic compounds using element-specific detectors in general is based on matching the retention time with known standards. This works perfectly as long as known standards are available. When unknown signals are obtained in a chromatogram, ICP-MS cannot provide any structural information and other detectors must be applied. 

W Goessler, A Rudorfer, EA Mackey, PR Becker, KJ Irgolic. Determination of arsenic compounds in marine mammals with high performance liquid chromatography and an inductively coupled plasma mass spectrometer as element specific detector. Appl Qrganomet Chem 12 491-501, 1998. 

A range of chromatographic techniques coupled to element specific detectors has been used in speciation studies to separate individual organometallic species (e.g., butyltins, arsenic species) and to separate metals bovmd to various biomolecules. The combination of a chromatographic separation with varying instrumental detection systems are commonly called coupled, hybrid, or hyphenated techniques (e.g., liquid chromatography inductively coupled plasma-mass spectrometry (LC-ICP-MS), gas chromatography-atomic absorption spectroscopy (GC-AAS)). The detection systems used in coupled techniques include MS, ICP-MS, atomic fluorescence spectrometry (AFS), AAS, ICP-atomic emission spectrometry (ICP-AES), and atomic emission detection (AED). 

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