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Capillary Electrophoretic Determination of Oxalate in Amniotic Fluid



B C. Nelson, G F. Rockwell, T Campfield, P O'Grady, R M. Hernandez, Stephen Wise


A capillary electrophoretic (CE) assay for oxalate has been applied to the quantitative determination of free oxalate in amniotic fluid. Indirect absorbance detection of oxalate is accomplished with a chromate-based background electrolyte modified with ethylenediaminetetraacetic acid (EDTA). Detection interference due to the presence of high levels (approximately equal to} 4 mg/ml) of inorganic chloride is eliminated through a direct sample clean-up procedure based on cation (Ag+-form) resins. Separation interference from amniotic fluid proteins is prevented through the use of a simple aqueous-based dilution procedure. This method for the determination of oxalate in amniotic fluid provides precision of approximately equal to} 5 % relative standard deviation (RSD). Within-day precisions for the oxalate peak response and migration time are better than 3% RSD and 1% RSD, respectively. Between-day precisions for the oxalate response and migration time are better than 6% RSD and 3% RSD, respectively. The analytical recovery of oxylate (1000 ng/ml) spiked into amniotic fluid was better than 96%. The limit of detection (LOD) for the method is approximately equal to} 100 ng/ml oxalate. This method also shows promising results for the determination of oxalate in human blood plasma samples.
Analytica Chimica Acta


amniotic fluid, biological fluids, blood plasma, capillary electrophoresis, oxalate, total parenteral nutrition solutions


Nelson, B. , Rockwell, G. , Campfield, T. , O'Grady, P. , Hernandez, R. and Wise, S. (1999), Capillary Electrophoretic Determination of Oxalate in Amniotic Fluid, Analytica Chimica Acta (Accessed June 19, 2024)


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Created April 19, 1999, Updated October 12, 2021