Selective determination of toxicologically important arsenic species in urine by high-performance liquid chromatography–hydride generation atomic absorption spectrometry

Abstract

In studies on arsenic exposure and its monitoring, a method for the selective determination of trivalent and pentavalent inorganic arsenic, monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) in urine was developed. The method is based on the ion-pair chromatographic separation of arsenic species and continuous hydride generation for the determination of arsenic in the chromatographic effluent by atomic absorption spectrometry. The chromatographic separation was completed within 4 min by using tetrabutylammonium ion in phosphate buffer as the ion-pairing agent and a C,* reversed-phase column. The detection limits were 1 .O, 1.6, 1.2 and 4.7 pg dm-3 of arsenic for Ast11, AsV, MMA and DMA, respectively. These detection limits are not low enough to detect the lowest levels of these arsenic species in the urine of unexposed subjects. However, accurate measurement of the concentrations due to occupational exposure is easily achieved.

Evaluation of atomic fluorescence spectrometry as a sensitive detection technique for arsenic speciation

“…Limits of detection between 3.5 and 21.3 m g l À1 have been reported for the HPLC-HG-ICP-AES coupling 8 (using a 100-l sample loop), and between 1.0 and 4.7 mg l À1 for HPLC-HG-AAS 9 (with a 50-ml loop). These levels are sometimes not low enough to detect the arsenic species present in water or biological samples.…”

A study of sample mineralization methods for arsenic analysis of blood and urine by hydride generation and graphite furnace atomic absorption spectrometry

“…One procedure is based on dry ashing with magnesium nitrate, and the second is based on microwave-assisted decomposition with the addition of ammonium persulfate. Dry ashing methods described earlier using Mg(NO 3 ) 2 as an ashing aid [2], [17], [18] were modi¯ed and simpli¯ed to shorten whole process of the sample preparation to less than 2 hours. In addition, the presence of Mg(NO 3 ) 2 in samples is advantageous for GFAAS measurements, because if combined with palladium, it is often used as an universal modi¯er [12].…”

“…After the intake of toxic inorganic arsenic compounds, however, the element is methylated \in vivo" and then excreted as methylated compounds with dimethylarsinic acid (DMA) and monomethylarsonic acid (MMA) being the major metabolites found in urine [2], [3]. Exposure to MMA and DMA can also be due to their use as selective herbicides [4].…”

Stoffmonographie Arsen?Referenzwert f�r Urin

“…Im Schrifttum findet sich heute eine Reihe von analytischen Methoden, mit denen die im Urin ausgeschiedenen unterschiedlichen organischen und anorganischenArsenverbindungen zunächst chromatographisch getrennt und anschließend mittels AAS oder ICP-MS bestimmt werden können [64,65,66,67,68,69]. Mittlerweile hat auch die DFG eine dem Stand der Technik entsprechende Methode zur Bestimmung von Arsenspezies veröffentlicht [70].Es handelt sich um ein Verfahren, bei dem die einzelnen Arsenspezies zunächst hochdruckflüssig-keitschromatographisch getrennt und nach Überführung in die jeweiligen Arsenhydride atomabsorptionsspektrometrisch bestimmt werden.…”