Comparison of three methods for the extraction of arsenic compounds from the NRCC standard reference material DORM‐2 and the brown alga Hijiki fuziforme

Abstract

The NRCC standard reference material DORM-2 and the marine brown alga Hijiki fuziforme were extracted with water, methanol/water (9 1), and 1.5 M orthophosphoric acid. The extracts from DORM-2 were analyzed by HPLC-ICP-MS for arsenobetaine, arsenocholine, trimethylarsine oxide, and the tetramethylarsonium cation and the extracts from H. fuziforme for arsenous acid, arsenic acid, dimethylarsinic acid, methylarsonic acid, and four arsenoriboses. Almost no differences between the three extractants were observed when DORM-2 was investigated. Only arsenobetaine was slightly better extracted with 1.5 M orthophosphoric acid or methanol/water (9 1) than with water. The sum of all extractable compounds (arsenobetaine, the tetramethylarsonium cation, and a formerly unknown compound recently identified as the trimethyl(2-carboxyethyl)arsonium ion) accounted for 94% of the total arsenic when 1.5 M orthophosphoric acid was used, for 92% when methanol/water (9 1) was used, and for 87% when water was used. Significant differences in the extraction yields obtained for the alga were observed for arsenic acid and one of the arsenoriboses ('glycerol-ribose'). Orthophosphoric acid removed twice as much of this ribose from the algal material than water and three times more than methanol/water (9 1). Arsenic acid was 1.2 times better extracted with orthophosphoric acid than with water and ten times better than with methanol/water (9 1). Almost no differences in the extraction yields were found for dimethylarsinic acid and the other three riboses. Orthophosphoric acid extracted 76%, water 65%, and methanol/water 33% of the total arsenic from H. fuziforme.

Comparison of mild extraction procedures for determination of arsenic compounds in different parts of pepper plants (Capsicum annum, L.)

“…In the case of the marine alga Hijiki fusiforme, the extractability of arsenic compounds increased from 33% with a methanol/water (9/1) mixture to a 74% extraction yield with 1.5 mol l −1 orthophosphoric acid. 11 For the freshwater alga Chlorella vulgaris, the recoveries of total arsenic ranged from 74% for a water extraction to 100% with methanol-water mixtures in which the methanol concentration was above 40% (v/v). A 0.03 mol l −1 phosphate buffer extracted 84% of total arsenic.…”

Development of Isotope Dilution LC-MS/MS Method for Accurate Determination of Arsenobetaine in Oyster Certified Reference Material

“…A large number of studies on the extraction of organoarsenic compounds have been reported. [37][38][39][40][41][42][43][44][45][46] Although the extraction efficiencies were different depends on the matrices and extraction steps involved, most of them reported decent efficiencies between 90-110%. Mechanical shaking, sonication, and pressurized extraction including MW extraction have been used predominantly.…”

Speciation of trace element compounds in samples of biota from marine ecosystems

“…Mixtures of water, water -methanol and methanol -chloroform have been used to establish the best composition for efficiently extracting water-soluble species Hanaoka et al, 2001;Kuehnelt et al, 2001;Brisbin and Caruso, 2002;Geiszinger et al, 2002). As this efficiency depends on the tissue and species to be analysed, the conclusion was reached that all arsenic species in different samples need diverse extraction conditions (Francesconi and Kuehnelt, 2004).…”