Arsenic Speciation In Water Research Articles

Arsenic speciation in water by high-performance liquid chromatography with electrothermal atomic absorption detection

A procedure was developed for determining arsenite, arsenate, monomethylarsonate, and dimethylarsinite ions in natural waters in concentrations 0.05–0.07 mg/L. The procedure involved separation by high-performance liquid chromatography and off-line determination by electrothermal atomic absorption spectrometry. The procedure was used to study arsenic transformations in the aquatic ecosystem of a tailing pit of an ore-dressing industrial plant.

Arsenic Speciation in Water and Human Urine by HPLC–ICP-MS and HPLC–MO–HG-AAS

Arsenite, arsenate, monomethylarsonate, dimethylarsinate, arsenobetaine, and arsenocholine have been successfully separated in one chromatographic run in a mixed mode column, Spherisorb ODS/NH2, using 5.0 mmol liter−1phosphate buffer at pH 5.0 as mobile phase and final detection by inductively coupled plasma mass spectrometry (ICP-MS) or microwave-assisted oven (MO) coupled with hydride generation atomic absorption spectrometry (HG-AAS). The detection limits achieved with the HPLC–ICP-MS coupling (0.04–0.28 ng) were about 20 times lower than those achieved by HPLC–MO–HG-AAS, which makes it suitable for determining these species at their naturally occurring concentration levels. The chloride present in the samples was chromatographically separated from the arsenic species, and the interferent signal from the40Ar35Cl formed on the ICP-MS system was insignificant. The proposed methods were successfully applied to the determination of six arsenic species in water and urine (after previous cleanup of the sample).

Organometallics in the nearshore marine environment of Australia

AbstractThis review draws together published information on the occurrence and biogeochemical cycling of selenium, arsenic and tin in the nearshore marine environment of Australia. The selenium content of marine organisms is well documented but little information is available on the selenium content of waters and sediments. The speciation of selenium in organisms, water and sediments is unknown although it appears that selenium is associated with proteins. The occurrence and speciation of arsenic in marine organisms has been extensively studied, with arsonobetaine being isolated as the probable end‐product of arsenic metabolism in marine food chains. However, organisms can produce other organoarsenic compounds, e.g. trimethylarsine oxide, which may be metabolized to toxic end‐products. Little is known about the occurrence and speciation of arsenic in waters and sediments. Arsenic(V) is dominant in oxygenated waters, with appreciable quantities of arsenic(III) in some deoxygenated waters.There are few data for tin in water, sediments or organisms and no data on naturally occurring tin species. Tributyltin has been measured in water, sediment and organisms from areas affected by boating activity.

Arsenic speciation in water by hydride cold trapping-quartz furnace atomic absorption spectrometry: an evaluation

Arsenate, arsenite, monomethylarsonate, monoethylarsonate and dimethylarsinate are speciated in environmental waters. After pH-dependent hydride generation, the arsines are collected on a cold trap and volatilised sequentially into a quartz furnace atomic absorption spectrometer.The various parameters of the methodology are optimised, and their influence critically discussed and compared with other methods. Aspects such as interferences in organoarsenic speciation, the effect of atomisation support gases in collection mode techniques and unambiguous identification of dimethylarsine are emphasised in particular. An evaluation of the analytical characteristics and performance of the method is presented, using representative environmental samples. This paper attempts to illustrate the advantages and drawbacks of the technique and includes a review of recent progress in arsenic hydride methodology.