| Title | Comparison of three sequential extraction procedures for arsenic fractionation in highly polluted sites. |
|---|---|
| Authors | X. Wan; H. Dong; L. Feng; Z. Lin; Q. Luo |
| Journal | Chemosphere |
| DOI | 10.1016/j.chemosphere.2017.03.078 |
| Abstract |
Three sequential extraction procedures (SEPs) including Tessier, Rauret, and Shiowatana SEPs, were compared for arsenic fractionation using highly polluted soils. In the definition context of exchangeable, reducible, oxidizable and residual fractions, with similar arsenic recovery and reproducibility, Tessier and Rauret SEPs were comparable to each other, whereas Shiowatana SEP showed higher extraction efficiency in all the first three arsenic fractions, although it might overestimate the reducible arsenic. Pot experiment indicated three SEPs all could provide an estimation of the most bioavailable arsenic fraction, and the application of Shiowatana SEP should be preferred. Accordingly, a case study with Shiowatana SEP for a site near a realgar mine area is conducted. The results show that although arsenic in this area presents predominantly in the stable fractions, the sum of most bioavailable fractions was accounted around 11% of total arsenic, and moreover, about another 10% of the total arsenic, the fourth fraction in Shiowatana SEP is likely to be transferred into bioavailable species under suitable conditions, such as strong acid impact, revealing a real major risk source being formed. The study indicated that Shiowatana should be more suitable for arsenic fractionation to provide valuable information in the framework of risk assessment. |
See more Arsenic products. Arsenic (atomic symbol: As, atomic number: 33) is a Block P, Group 15, Period 4 element with an atomic radius of 74.92160. 
The number of electrons in each of arsenic's shells is 2, 8, 18, 5 and its electron configuration is [Ar] 3d10 4s2 4p3. The arsenic atom has a radius of 119 pm and a Van der Waals radius of 185 pm. Arsenic was discovered in the early Bronze Age, circa 2500 BC. It was first isolated by Albertus Magnus in 1250 AD. In its elemental form, arsenic is a metallic grey, brittle, crystalline, semimetallic solid. 
Arsenic is found in numerous minerals including arsenolite (As2O3), arsenopyrite (FeAsS), loellingite (FeAs2), orpiment (As2S3), and realgar (As4S4). Arsenic has numerous applications as a semiconductor and other electronic applications as indium arsenide, silicon arsenide and tin arsenide. Arsenic is finding increasing uses as a doping agent in solid-state devices such as transistors.