Author/Editor     Goessler, Walter; Kuehnelt, Doris; Schlagenhaufen, Claudia; Šlejkovec, Zdenka; Irgolič, Kurt J
Title     Arsenobetaine and other arsenic compounds in the National research council of Canada certified reference materials DORM 1 and DORM 2
Type     članek
Source     J Anal Atom Spectrom
Vol. and No.     Letnik 13
Publication year     1998
Volume     str. 183-7
Language     eng
Abstract     A silica-based cation-exchange column was used to determine the arsenic compounds in the National Research Council of Canada (NRCC) CRMs DORM 1 and DORM 2 (Dogfish Muscle). With a 20 mM aqueous pyridine mobile phase at pH 3.0, the concentration of arsenobetaine was only 10.7 mg kg-1 As in the extract of DORM 1. When the same extract was chromatographed on an anion-exchange column, 15.9±0.3 mg kg-1 As (arsenobetaine) were found. The calibration for arsenobetaine was Gnear from 0.5 pg dm-1 As to 10 mg dm-3 As. When the extracts were diluted with water the cation-exchange results approached the anion-exchange results. The multi-element capabilities of ICP-MS allowed the simultaneous monitoring of arsenic and alkali metals. Sodium and potassium were found to co-elute with arsenobetaine. Wheo aqueous solutions of arsenobetaine with 250 mg dm-3 Na were chromatographed, the signal obtained for arsenobetaine was only 60% of the signal without sodium in the solution. When the pH of the 20 mM aqueous pyridine mobile phase was lowered, the alkali metals were separated from arsenobetaine and the results obtained from cationexchange chromatography were not significantly different from the anion-exchange results. Because DORM 1 is no longer available, the arsenic compounds in DORM 2 were determined. No significant difference was found for the concentration of arsenobetaine (15.6 ± 0.7 mg kg-1 As for DORM 1; 16.0±0.7 mg kg-1 As for DORM 2). The concentrations of the minor arsenic compounds (dimethylarsinic acid, arsenocholine, the tetramethylarsonium cation and an unknown arsenic compound) in DORM 2 were only half the concentrations in DORM 1.
Descriptors     ARSENICALS
BETAINE
MUSCLES
DOGFISH
REFERENCE STANDARDS
CHROMATOGRAPHY, HIGH PRESSURE LIQUID
SPECTRUM ANALYSIS, MASS