Determination of oxalate in human plasma and urine by RP-HPLC / 中草药

ABSTRACT

Objective: To establish a method of reversal phase-high performance liquid chromatography (RP-HPLC) for determining the mass concentration of oxalate in human plasma and urine and to monitor the variation of mass concentration of oxalate in the patients with primary hyperoxaluria (PH) before and after combined liver-kidney transplantation. Methods: Agilent XDBC18 (150 mm × 4.6 mm, 5 μm) column and Agilent Zorbax extend-C18 (12.5 mm × 4.6 mm, 5 μm) guard column were used. Methyl alcohol and aqueous solution containing 0.1 mol/L ammoniom acetate (15∶85) were used as mobile phase. The flow rate was at 1.2 mL/min, ultraviolent determination wavelength was 314 nm, column temperature was at 26.3 ℃, and injection volume was 50 μL. o-phenylenediamine was used as derivating agent, reacted with oxalate in human plasma and urine so as to obtain the compound with better ultraviolet absorption-2, 3-dyhydroxy quinoxaline. Results: The detection limit in human plasma was 0.3 mg/L, the linear range was 1.953-125 mg/L, the average recovery was 94.89%, and its RSD was 4.1%; The detection limit in urine was 0.5 mg/L, the linear range was 1.953-125 mg/L, the average recovery was 94.31%, and its RSD was 3.2%. Conclusion: The method is believable for determining the mass concentration of oxalate with its simplicity, sensibility, repeatability, and better recovery rate.