Atomic absorption spectrometry arsenic

FLOW INJECTION ELECTROCHEMICAL HYDRIDE GENERATION ATOMIC ABSORPTION SPECTROMETRY EOR THE DETERMINATION OE ARSENIC... 

MDHS41 Arsenic and inorganic compounds of arsenic in air (atomic absorption spectrometry). 

Zhang X, Cornelis R, De Kimpe J, and Mees L (1996) Arsenic speciation in serum of uraemic patients based on liquid chromatography with hydride generation atomic absorption spectrometry and on-line UV photo-oxidation digestion. Anal Chim Acta 319 177-185. 

Munoz O, Velez D, Montoro R (1999) Optimization of the solubilization, extraction and determination of inorganic arsenic [As(III) i- As(V)] in seafood products by acid digestion, solvent extraction and hydride generation atomic absorption spectrometry. Analyst 124 601-607. 

Howard and Comber [63] converted arsenic in seawater to its hydride prior to determination by atomic absorption spectrometry. 

Electrothermal atomic absorption spectrometry is used to study the total arsenic and arsenic (III) content in marine sediments [64]. 

Amankwah and Fasching [4] have discussed the determination of arsenic (V) and arsenic (III) in estuary water by solvent extraction and atomic absorption spectrometry using the hydride generation technique. 

Willie et al. [17] used the hydride generation graphite furnace atomic absorption spectrometry technique to determine selenium in saline estuary waters and sea waters. A Pyrex cell was used to generate selenium hydride which was carried to a quartz tube and then a preheated furnace operated at 400 °C. Pyrolytic graphite tubes were used. Selenium could be determined down to 20 ng/1. No interference was found due to, iron copper, nickel, or arsenic. 

It is seen by examination of Table 1.11(b) that a wide variety of techniques have been employed including spectrophotometry (four determinants), combustion and wet digestion methods and inductively coupled plasma atomic emission spectrometry (three determinants each), atomic absorption spectrometry, potentiometric methods, molecular absorption spectrometry and gas chromatography (two determinants each), and flow-injection analysis and neutron activation analysis (one determinant each). Between them these techniques are capable of determining boron, halogens, total and particulate carbon, nitrogen, phosphorus, sulphur, silicon, selenium, arsenic antimony and bismuth in soils. 

The determination of arsenic by atomic absorption spectrometry with thermal atomization and with hydride generation using sodium borohydride has been described by Thompson and Thomerson [117] and it was evident that this method could be modified for the analysis of soil. 

Cutter [122] used a selective hydride generation procedure as a basis for the differential determination of arsenic and selenium species in sediments. Goulden et al. [123] also discuss the determination of arsenic and selenium in sediments by atomic absorption spectrometry. 

The acid digestion procedure described above for biological tissues. Crock and Lichte [135] recently described a similar procedure, involving hydrofluoric as well as nitric, perchloric and sulphuric acids, for dissolution of geological materials prior to arsenic and antimony determination by atomic absorption spectrometry. 

Recently, Sakai et al. have combined flame Zeeman atomic absorption spectrometry (FZAAS) with selective vapourisation of the spaaes from a sample, placed in a crucible which is slowly heated, to investigate the speciation of arsenic compounds in oyster tissue. This method could prove useful if the top temperature reached by the system is high enough to allow the vapourisation of a wider variety of species that may exist in biological samples. Presently, the highest temperature attainable is 400 °C. 

The most useful chemical species in the analysis of arsenic is the volatile hydride, namely arsine (AsH3, bp -55°C). Analytical methods based on the formation of volatile arsines are generally referred to as hydride, or arsine, generation techniques. Arsenite is readily reduced to arsine, which is easily separated from complex sample matrices before its detection, usually by atomic absorption spectrometry (33). A solution of sodium borohydride is the most commonly used reductant. Because arsenate does not form a hydride directly, arsenite can be analyzed selectively in its presence (34). Specific analysis of As(III) in the presence of As(V) can also be effected by selective extraction methods (35). 

G. P. Brandao, R. C. Campos, A. S. Luna, E. V. R. Castro and H. C. Jesus, Determination of arsenic in diesel, gasoline and naphtha by graphite furnace atomic absorption spectrometry using microemulsion medium for sample stabilisation. Anal. Bioanal. Chem., 385(8), 2006, 1562-1569. 

M. V. Reboucas, S. L. C. Ferreira and B. De-Barros-Neto, Arsenic determination in naphtha by electrothermal atomic absorption spectrometry after preconcentration using multiple injections, J. Anal. At. Spectrom., 18(10), 2003, 1267-1273. 

B. Do, S. Robinet, D. Pradeau and F. Guyon, Speciation of arsenic and selenium compounds by ion-pair reversed-phase chromatography with electrothermal atomic absorption spectrometry. Application of experimental design for chromatographic optimisation, J. Chromatogr. A, 918(1), 2001, 87-98. 

H. Matusiewicz and M. Mroczkowska, Hydride generation from slurry samples after ultrasonication and ozonation for the direct determination of trace amounts of As (III) and total inorganic arsenic by their in situ trapping followed by graphite furnace atomic absorption spectrometry, J. Anal. At. Spectrom., 18, 2003, 751-761. 

S. A. Pergantis, W. R. Cullen and A. P. Wade, Simplex optimisation of conditions for the determination of arsenic in environmental samples by using electrothermal atomic absorption spectrometry, Talanta, 41(2), 1994, 205-209. 

X. Ch. Le, W. R. Cullen, K. J. Reimer and 1. D. Brindie, A new continous hybride generator for the determination of arsenic, antimony and tin by hydride generation atomic absorption spectrometry. Anal. Chim. Acta, 258(2), 1992, 307-315. 

R. B. Georgieva, P. K. Petrov, P. S. Dimitrov and D. L. Tsalev, Observations on toxicologically relevant arsenic in urine in adult offspring of families with Balkan endemic nephropathy and controls by batch hydride generation atomic absorption spectrometry, Int. J. Environ. Anal. Chem., 87(9), 2007, 673-685. 

Inorganic As(III) and As(V) were determined by atomic absorption spectrometry using the hydride technique. Total inorganic arsenic, As(III) + As(V), was measured after a prereduction reaction of As(V) to As(III) in acidic solution containing potassium iodide and ascorbic acid. For the selective hydride formation of As(III), samples were maintained at pH 5.0 during the hydride reaction (with 3% NaBH4, 1% NaOH) with a citrate-sodium hydroxide buffer solution (31). As(V) was determined by difference between total As and As(III). The detection limit of As(III) and As(V) was 0.1 nM. The selectivity of this method was checked by additions of As(III) and As(V) to lake water 95-100% recovery of As(III) and As(V) was found (32). 

Samanta, G Chowdhury, T.R., Mandal, B.K. et al. (1999) Flow injection hydride generation atomic absorption spectrometry for determination of arsenic in water and biological samples from arsenic-affected districts of West Bengal, India, and Bangladesh. Microchemical Journal, 62(1), 174-91. 

Cano-Aguilera, I., Haque, N., Morrison, G.M. et al. (2005) Use of hydride generation-atomic absorption spectrometry to determine the effects of hard ions, iron salts and humic substances on arsenic sorption to sorghum biomass. Microchemical Journal, 81(1), 57-60. 

Coal contains several elements whose individual concentrations are generally less than 0.01%. These elements are commonly and collectively referred to as trace elements. These elements occur primarily as part of the mineral matter in coal. Hence, there is another standard test method for determination of major and minor elements in coal ash by ICP-atomic emission spectrometry, inductively coupled plasma mass spectrometry, and graphite furnace atomic absorption spectrometry (ASTM D-6357). The test methods pertain to the determination of antimony, arsenic, beryllium, cadmium, chromium, cobalt, copper, lead, manganese, molybdenum, nickel, vanadium, and zinc (as well as other trace elements) in coal ash. 

In an interlab oratory study involving 160 accredited hazardous materials laboratories reported by Kimbrough and Wakakuwa [28], each laboratory performed a mineral acid digestion on five soils spiked with arsenic, cadmium, molybdenum, selenium and thallium. Analysis of extracts was carried out by atomic emission spectrometry, inductively-coupled plasma mass spectrometry, flame atomic absorption spectrometry and hydride generation atomic absorption spectrometry. 

Martens and Suarez [37 ] employed sequential extraction and hydride generation atomic absorption spectrometry to analyse soil for arsenic and selenium and achieved excellent precision. 

Mierzwa and Dobrowolski [39 ] determined selenium using combined slurry sampling, microwave-assisted extraction and hydride atomic absorption spectrometry. Lopez-Garcia et al. [40] also used slurry sampling in the determination of arsenic and antimony in soil. 

An early method for the determination of arsenic in soils is that of Forehand et al. [23]. This method is based on the selective extraction of arsenic(III) by benzene and analysis of the extract by atomic absorption spectrometry. Firstly the soil is allowed to stand with 9.9 M hydrochloric acid for 12 hours, and then the arsenic is reduced from arsenic(V) to arsenic(III) with stannous chloride and potassium iodide. Following adjustment to pH 9 with hydrochloric acid, the aqueous phase is extracted with benzene. The benzene extract is then treated with water and the water extract analysed by atomic absorption spectrometry at 193.7 nm. An average recovery of 88% of the arsenic present in sandy soils was achieved by this procedure. 

To avoid problems previously encountered with flame atomic absorption spectrometry of arsenic, and also with flameless methods such as that in which the dementis converted to arsine, Ohta and Suzuki [25] proposed an alternative method based on electrothermal ionisation with a metal microtube atomiser. Effective atomisation can be achieved by the addition of thiourea to the arsenic solution or by preliminary extraction of the arsenic-thionalide complex. The second method is recommended for soil samples so as to avoid interference due to the presence of trace elements. 

A UK standard method also discusses the determination of arsenic in soil by atomic absorption spectrometry [26]. 

The determination of arsenic by atomic absorption spectrometry with thermal atomisation and with hydride generation using sodium borohydride has been described by Thompson and Thomerson [29], and it was evident that this method couldbe modified for the analysis of soil. Thompson and Thoresby [30] have described a method for the determination of arsenic in soil by hydride generation and atomic absorption spectrophotometry using electrothermal atomisation. Soils are decomposed by leaching with a mixture of nitric and sulfuric acids or fusion with pyrosulfate. The resultant acidic sample solution is made to react with sodium borohydride, and the liberated arsenic hydride is swept into an electrically heated tube mounted on the optical axis of a simple, lab oratory-constructed absorption apparatus. 

Haring et al. [31] determined arsenic and antimony by a combination of hydride generation and atomic absorption spectrometry. These workers found that, compared to the spectrophotometric technique, the atomic absorption spectrophotometric technique with a heated quartz cell suffered from interferences by other hydride-forming elements. 

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