Hydride generation applications

Cutter [18] has studied the application of the hydride generation method to the determination of selenium in saline waters. 

Various workers have discussed the application of atomic absorption spectrometry to the determination of selenium in rocks [159,160] achieving detection limits of 0.06g g-1 [159] and 1.4xl0 10g g-1 [160] respectively. Hydride generation and measurement of hydride fluorescence has been used to determine selenium [120, 161] with a sensitivity of 0.06ug Se mL 1 which is 5-30 times than is achieved by conventional atomic absorption spectrometry. 

Odanake et al. [1] have reported the application of gas chromatography with multiple ion detection after hydride generation with sodium borohydride to the determination of mono and dimethyl arsenic compounds, trimethyl arsenic oxide and inorganic arsenic in soil and sediments. Recoveries in spiking experiments were 100-102% (mono and dimethyl arsenic compounds and inorganic arsenic) and 72% (trimethyl arsenic oxide). 

ICP, cold vapor mercury, and hydride generation in regard to applicability and detection limit. 

Various efficient devices have been utilized for sample introduction into an inductive plasma source, for example the application of several nebulizers, hyphenated techniques, hydride generation, laser ablation and electrothermal vaporization. The role of the solution introduction system in an inductively coupled plasma source is to convert the liquid sample into a suitable form (e.g.,... 

T. Stoichev, R. C. Rodriguez-Martin-Doimeadios, D. Amouroux, N. Molenat and O. F. X. Donard, Application of cryofocusing hydride generation and atomic fluorescence detection for dissolved mercury species determination in natural water samples, J. Environ. Monit., 4, 2002, 517-521. 

B. Hilligsoe and E. H. Hansen, Application of factorial designs and simplex optimisation in the development of flow injection-hydride generation-graphite furnace atomic absorption spectrometry (FI-HG-GFAAS) procedures as demonstrated for the determination of trace levels of germanium, Fresenius J. Anal. Chem., 358(7-8), 1997, 775-780. 

Tsalev, D.L., M. Sperling, and B. Welz. 1992,On-line microwave sample pre-treatment for hydride generation and cold vapour atomic absorption spectrometry. Part 2. Chemistry and applications. Analyst 117 1735-1741. 

Laborda, F., E. Bolea, and J.R. Castillo. 2007. Electrochemical hydride generation as a sample introduction technique in atomic spectrometry Fundamentals, interferences and applications. Anal. Bioanal. Chem. 388 743-775. 

Aggett and Kadwani [13] employed a two stage single column anion exchange method using sodium hydrogen carbonate and chloride as eluate anions. These species appear to have no adverse effects in subsequent analytical procedures. Its successful application is dependent on careful control of pH. Analyses were performed by hydride generation atomic absorption spectroscopy... 

Odanaka et al. [212] have reported that the combination of gas chromatography with multiple ion detection system and a hydride generation heptane cold trap technique is useful for the quantitative determination of arsine, monomethyl-, dimethyl- and trimethylarsenic compounds and this approach is applicable to the analysis of environmental and biological samples. 

Hydride and cold-vapour techniques represent a special combination of chemical separation and pre-enrichment with AAS determination, resulting in higher powers of detection for elements with volatile hydrides, eg, As, Bi, Se, Sb, Hg. Recent literature on vapour generation has been reviewed by Hill et al. (1991). Some examples of the use of hydride generation for the analysis of plant material are given by Muse et al. (1989), Leuka et al. (1990) and Ainsworth and Cooke (1990). Hydride generation can also be used with ICP-EAS (see below) and applications have been reviewed (Nakahara, 1991). 

It should be pointed out that few elements are present in most natural waters at concentrations where flame spectroscopic techniques are directly applicable. Those that are include calcium, magnesium, sodium, potassium, and, in some samples and if conditions are very carefully optimized, manganese, iron, and aluminium. Zinc, and sometimes cadmium, may be determined directly by AFS. Mercury and hydride-forming elements may be determined if cold vapour and hydride generation sample introduction techniques are employed, as discussed in... 

Because of the low wavelengths of its main resonance lines, tellurium is never routinely determined by flame AES, but the element may be determined with moderate sensitivity by flame AAS or AFS techniques, at 214.3 nm in an oxidizing air-acetylene flame. The detection limit is generally around 100 ng ml-1, which is inadequate for almost all environmental applications unless the element is pre-concentrated by a substantial factor.1 However, hydride generation plus AFS or AAS yields much more useful detection limits. Even so, pre-concentration may be necessary if the element is to be determined in natural waters, for example by extraction as the tributylphosphate complex.50 The... 

Hydride generation techniques are applicable to tin, and the detection limit is then improved dramatically, generally to around 1 ng ml-1. For natural water samples, the element is still sometimes pre-concentrated prior to determination by hydride generation techniques.52,53... 

Y. Madrid, J. Mesenguer, M. Bonilla, C. Camara, Lead hydride generation in lactic acid-potassium dichromate medium and its application to the determination of lead in fish, vegetables and drink samples, Anal. Chim. Acta, 237 (1990), 181-187. 

C. Baluja-Santos, A. Gonzalez-Portal, Application of hydride generation to atomic-absorption spectrometric analysis of wines and beverages a review, Talanta, 39 (1992), 329-339. 

The use of GC-MIP-AES is advantageous because it avoids the predecomposition step required in the AAS detection mode. The first applications of the MIP-AES detector for Hg speciation and detection were reported in the 1970s [27-29]. Despite the overall good detection ability of the detectors, however, most of the above methods require large sample volumes, tedious solvent extraction procedures, and usually lead to the final determination of only the Me-Hg species. The description of the feasibility of quantitative in situ aqueous ethylation of Hg2-1- and Me-Hg followed by on-line preconcentration and detection by atomic fluorescences pectro-metry (AFS) or AAS certainly produces a wealth of information since it allows all Hg species to be detected in the same chromatographic run. Also on-line speciation of Hg and Me-Hg by chromatography-AFS hydride generation (HG) was used [30]. 

Anderson R. K., Thompson M., and Culbard E. (1986) Selective reduction of arsenic species by continuous hydride generation Part II. Validation of methods for application to natural waters. Analyst 111, 1153-1157. 

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