Arsenic, total concentration

Arsenic. Total arsenic concentration can be determined by reduction of all forms to arsine (AsH ) and collection of the arsine in a pyridine solution of silver diethyldithiocarbamate. Organoarsenides must be digested in acidic potassium persulfate prior to reduction. The complex that forms is deep red, and this color can be measured spectrophotometricaHy. Reduction is carried out in an acidic solution of KI—SnCl2, and AsH is generated by addition of 2inc. 

Total arsenic concentrations in selected nonbiological materials... 

Table 28.1 Total Arsenic Concentrations in Selected Nonbiological Materials...

Table X. Comparison of total arsenic concentrations on generated filters determined by IC-AAS, NAA, and XRF analysis techniques.

Approximate Total Arsenic Aerosol Concentration Level (yg/m ) Total Arsenic Concentration Found (yg/m ) ... 

Tables I to III provide a summary of some representative data for total arsenic concentrations in sediments, marine algae, and marine animals. There can be considerable variation in the arsenic levels in these samples, in contrast to the levels in seawater, which are reasonably uniform in the world s oceans at about 0.5-2 /ug/liter (9,10). For sediments, there is perhaps a tendency for arsenic concentrations to be lower in samples from coastal regions and estuaries compared with deep-sea sediments. Industrial discharges of arsenic-enriched effluents can, however, result in arsenic contamination of near-shore sediments...

The later observation of Morita and Shibata (19) is relevant here. They examined the distribution of the various arsenic compounds in Hizikia fusiforme (this alga is unusual in that it contains about 50% of its total arsenic as arsenate). The total arsenic concentrations were higher at the surface layers than in the center of the alga. Arsenate... 

Ingested arsenic is known to be not only excreted by urine, but also to be stored in sulfydryl rich tissue like hair, nails or skin. A method of extracting arsenic species from hair and nail samples has been developed for the analysis of the total arsenic concentration, inorganic As ( ) and As... 

Stream Number Stream Source Liquid Flowrate (GPD) Arseni c Rate (Ib/MO) Percent Arsenic to HF Treatment System and Recycled Solids Total Arsenic Concentration (mg/L) Percent Solids Soluble Arsenic Concentration (mg/L)... 

The speciation of arsenic compounds, using IPC and ICP-MS as a detector, has received much attention [33-39]. Beauchemin et al. [33,34] used IPC for the analysis of arsenic species in dogfish muscle. The ion-pair reagent was 10 iM sodium dodecylsulfate in a 5% methanol, 2.5% glacial acetic acid mobile phase at pH 2.5 with a C18 column. The toxic inorganic species, As (III) and As (V), as well as the less toxic organoarsenic species, monomethylarsenic (MMA), dimethylarsenic (DMA), arsenobetaine (AB), and arsenocholine (AC), were separated. AB was the dominant species and constituted 84% of the total arsenic concentration with a detection limit of 300 pg (as As). 

M. J. Campbell, C. Demesmay, M. Olle, Determination of total arsenic concentrations in biological matrices by inductively coupled plasma mass spectrometry, J. Anal. Atom. Spectrom., 9 (1994), 1379-1385. 

Z. Slejkovec, J. T. van Elteren, U. D. Woroniecka, Underestimation of the total arsenic concentration by hydride generation techniques as a consequence of the incomplete mineralization of arsenobetaine in acid digestion procedures, Anal. Chim. 

Arsenic is metabolised to monomethylarsonic acid and dimediylarsinic acid. Individuals exposed to arsenic, such as glass workers, may have a total arsenic concentration in the urine of up to 0.07 LLg/ml, more than 50% of it appearing as... 

Concentration and chemical forms of arsenic in freshwater environment have been reviewed in detail by the present author . When comparing freshwater and marine organisms in the natural environment, there seems to be a clear difference in the total arsenic concentration, which in freshwater organisms is lower than in marine organisms. Trimethyl-, dimethyl- and monomethylarsenic compounds were detected in freshwater organisms whose chemical structure in vivo have not been confirmed . 

Human exposure to arsenic has been mainly assessed in the past by the determination of the total arsenic concentration in blood, hair, nails, and urine. In cases of suspected arsenic poisoning gastric juice has also been analyzed. In order to obtain meaningful data, however, it is important to determine the chemical form of arsenic, at least in body fluids. Depending on the source and length of exposure, these indicators have a different meaning and different significance as well (Foa et al., 1987 Vahter, 1988). 

Certified reference materials are commercially available for total arsenic concentrations in e.g. water, bovine liver, some plant materials, various environmental materials, oyster tissue, albacore tuna, mixed diets, milk powder and urine (LGC, 1992) but no materials are yet available with certified amounts of arsenic species. However, work is under way at... 

The effect of nascent oxygen on the oxidation of As(III) to As(V) is evident from the fact that in a wide range of SFR, from 2 to 300 BV/h, the total arsenic concentration in the effluent of chlorinated water was constantly below the MFC value [47] (Figure 5(A)). On the other hand, in the case of non-chlorinated water, the arsenic concentrations in the effluent at the SFR<100 BV/h were by 10 times and at 100[Pg.90]

II. ANALYTICAL METHODS FOR THE DETERMINATION OF TOTAL ARSENIC CONCENTRATIONS... 

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