Analysis of meso-2,3-dimercaptosuccinic acid in human urine by capillary electrophoresis using direct injection.
meso-2,3-Dimercaptosuccinic acid ( meso-DMSA) is an effective chelating agent for the treatment of lead poisoning. We have developed a capillary electrophoresis (CE) method to monitor the urinary excretion of meso-DMSA in human beings. The urine sample was directly injected for analysis in CE without the requirement of solid-phase extraction (SPE). The meso-DMSA was detected in 20 mM borate buffer (pH 8.3) using a 60-cm length bare fused-silica capillary (75-microm ID, 52.5-cm effective length). The meso-DMSA can be extensively biotransformed during metabolism, and no meso-DMSA in urine samples was found in our studies. Any metabolized meso-DMSA can be successfully converted to free meso-DMSA by chemical reduction with dithiothreitol (DTT). In addition, samples were also treated with ethylenediaminetetraacetic acid (EDTA) to transchelate any meso-DMSA that is coordinated with metal ions present in the urine samples. The total amount of meso-DMSA present as these chemical forms was quantified after chemical reduction and addition of EDTA. The detection limit of meso-DMSA was about 50 microM, the RSD of peak area and migration time of meso-DMSA were 4-8% and less than 1%, respectively.
Zhu
Xiaofeng
X
Department of Chemistry, University of Missouri, Columbia, MO 65211, USA.
Lever
Susan Z
SZ
D002614:Chelating Agents / Q000032:analysis*; D004229:Dithiothreitol / Q000737:chemistry; D004492:Edetic Acid / Q000737:chemistry; D019075:Electrophoresis, Capillary / Q000379:methods; D006801:Humans; D013237:Stereoisomerism; D004113:Succimer / Q000032:analysis*; D013997:Time Factors; D014556:Urine / Q000737:chemistry*
D002614:Chelating Agents; D004492:Edetic Acid; D004113:Succimer; D004229:Dithiothreitol