Inorganic arsenic determination

N.V. Semenova, L.O. Leal, R. Forteza, V. Cerda, Multisyringe flow-injection system for total inorganic arsenic determination by hydride generation-atomic fluorescence spectrometry, Anal. Chim. Acta 455 (2002) 277. 

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. 

In the method for [17] inorganic arsenic the sample is treated with sodium borohydride added at a controlled rate (Fig. 10.1). The arsine evolved is absorbed in a solution of iodine and the resultant arsenate ion is determined photometrically by a molybdenum blue method. For seawater the range, standard deviation, and detection limit are 1—4 xg/l, 1.4%, and 0.14 pg/1, respectively for potable waters they are 0-800 pg/1, about 1% (at 2 pg/1 level), and 0.5 pg/1, respectively. Silver and copper cause serious interference at concentrations of a few tens of mg/1 however, these elements can be removed either by preliminary extraction with a solution of dithizone in chloroform or by ion exchange. 

Organic arsenic species can be rendered reactive either by photolysis with ultraviolet radiation or by oxidation with potassium permanganate or a mixture of nitric acid and sulfuric acids. Arsenic (V) can be determined separately from total inorganic arsenic after extracting arsenic (III) as its pyrrolidine dithiocarbamate into chloroform [15]. 

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). 

Maher [13] has described a procedure for the determination of inorganic arsenic, monomethylarsenic and dimethylarsenic in marine organisms and estuarine sediments. The arsenic species are isolated by solvent extraction, separated by ion-exchange chromatography and selectively determined by arsine generation. Recoveries of spikes of 5 and lOpg of arsenic taken through the whole procedure were 92-96%. 

R02019 Method 1631, Revision E Mercury in Water by Oxidation, Purge and Trap, and Cold Vapor Atomic Eluorescence Spectrometry 821R96013 Method 1632 Determination of Inorganic Arsenic in Water by Hydride Generation Elame Atomic Absorption... 

R95028 Method 1632 Determination of Inorganic Arsenic in Water by Hydride Generation Elame Atomic Absorption [Draft]... 

Figure 2. Mechanism of dihydroxyacetone/arsenate reaction with FDP aldolase. Both dihydroxyacetone and inorganic arsenate are not the inhibitor of the aldolase reactions. The rate constant for the arsenate ester formation is determined enzymatically (a plot of 1/v vs 1/E gives a non-zero intercept which is attributed to the rate at infinite enzyme concentration and that rate corresponds to the rate of nonenzymatic formation of the arsenate ester).

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. 

The distillation separation procedure was the principal method used for the arsenic determinations, but more recently Santoliquido (24) has developed a method for the carrier-free separation of arsenic from low-temperature coal ash involving retention on an inorganic exchanger column. 

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). 

Hakala, E. and Pyy, L. (1995) Assessment of exposure to inorganic arsenic by determining the arsenic species excreted in urine. Toxicology Letters, 77(1-3), 249-58. 

Yamauchi, H., Takahashi, K., Mashiko, M. and Yamamura, Y. (1989) Biological monitoring of arsenic exposure of gallium arsenide- and inorganic arsenic-exposed workers by determination of inorganic arsenic and its metabolites in urine and hair. American Industrial Hygiene Association Journal, 50(11), 606-12. 

Liang, P. and Liu, R. (2007) Speciation analysis of inorganic arsenic in water samples by immobilized nanometer titanium dioxide separation and graphite furnace atomic absorption spectrometric determination. Analytica Chimica Acta, 602(1), 32-36. 

Braman, R.S., 3ohnson, D.L., Foreback, C.C., Ammons, 3.M. and Brick, 3.C., 1977. Separation and determination of nanogram amounts of inorganic arsenic and methylarsenic compounds. Anal. Chem., 49 621-625. 

The limitations of the Gutzeit method for determining arsenic are well-known. The spectrophotometric molybdenum blue or silver diethyldithio-carbamate procedures tend to suffer from poor precision. Sandhu [34] has described a spectrophotometric method for the direct determination of hydrochloric acid-releasable inorganic arsenic in soils and sediments. The method provides reliable data on the quantitative recovery of 2.0 xg of arsenic(V) added to 5.0 g (0.4 mg/kg) of soil, clay, sand and sediment samples. The method is simple, reliable and relatively rapid 24 samples can be analysed in about an hour. It does not require elaborate equipment and can be routinely used for the quantitative determination of arsenic in soil and soil-like material. The detection limit has been established as 0.5 xg of arsenic. The extent of ionic interference when this method is used for arsenic determination in soil was also quantitatively evaluated. 

Barra et al. [40] have described a microwave-assisted procedure based on atomic fluorescence for the quantitative determination of down to 0.006 xg/g of inorganic arsenic in soils. 

Cutter, L.S., Cutter, G.A. and Diego-McGlone, M.L.C. (1991) Simultaneous determination of inorganic arsenic and antimony species in natural waters using selective hydride generation with gas chromatographic/photoionization detection. Anal. Chem., 63, 1138-1142. 

These methods use either a gold- or a mercury-based electrode.64 65 Despite past problems with determining inorganic arsenic species, Salaiin et al65 showed that As(III) can be determined by ASV using a gold microwire electrode at any pH, including the neutral pH typical of natural waters, whereas As(V) requires acidification to pH 1. Detection limits with this microelectrode are 0.2 nM As(III) at pH 8 and 0.3 nM combined arsenic (III + V) at pH 1 with a 30-s deposition time (Table 7.2). Additionally, copper is codetermined with this technique. 

Arsenical herbicides (methane arsonate, dimethyl arsenite) and inorganic arsenic at the pg L 1 level have been determined in run-off water [266],... 

Butler [3] determined inorganic arsenic species in non saline waters by ion exclusion chromatography with electrochemical detection. Two species were separated by ion exclusion chromatography using 0.10M orthophosphoric acid eluent. Arsenic(III) was detected by its oxidation at a platinum wire electrode. Measurement of total inorganic arsenic after reduction of arsenic(V) to arsenic(III) by sulphur dioxide enabled... 

Henry et al. [26] reported a method for the determination of As(III), As(V) and total inorganic arsenic by differential pulse polarography. As(III) was measured directly in 1M perchloric acid or 1M hydrochloric acid. Total inorganic arsenic was determined in either of these supporting electrolytes after the reduction of electroinactive As(V) with aqueous sulphur dioxide. As(V) was evaluated by difference. Sulphur dioxide was selected because it reduced As(V) rapidly and quantitatively, and excess reagent was readily removed from the reaction mixture. 

A. Martinez, A. Morales-Rubio, M. L. Cervera, M. de la Guardia, Atomic fluorescence determination of total and inorganic arsenic species in beer, J. Anal. Atom Spectrom., 16 (2001), 762-766. 

J. Brooke, W. H. Evans, Determination of total inorganic arsenic in fish, shellfish and fish products, Analyst, 106 (1981), 514-520. 

Apparatus Refer to the figure Special Apparatus for the Determination of Inorganic Arsenic (Arsenic Limit Test, Appendix IIIB). Have all parts available for assembly during the Procedure. 

---