Oxalate, phosphate and sulphate determination in serum and urine by ion chromatography

A rapid method for the determination of phosphate, sulphate and oxalate in serum by ion chromatography is described. Serum is deproteinized through a Centrifree filter by centrifugation and the ultrafiltrate directly injected into an ion chromatograph equipped with an anion exchange column and a conductivity detector. By this procedure the sample is not diluted and even small amounts of oxalate in biological fluids can be detected. Mean serum concentrations found in healthy individuals are: phosphate 1.07 mmol/l; sulphate 0.35 mmol/l; oxalate 21.02 mumols/l. Phosphate, sulphate and oxalate contents were also determined in urine from healthy individuals. Values found in serum and urine are in good agreement with those previously reported.