Simultaneous determination of uric acid and creatinine in plasma by reversed-phase liquid chromatography.

Abstract

Because numerous substances, endogenous compounds as well as xenobiotics, interfere with determination of uric acid and creatinine, we have devised a more nearly specific method by which we can simultaneously determine uric acid and creatinine in plasma by "high-performance" liquid chromatography. We used a mobile phase of ammonium acetate (30 mmol/L) and methanol (156 mmol/L) at pH 7.0 and a flow rate of 1 mL/min. We used a C18 reversed-phase column, and measured absorbance at 235 nm, the wavelength corresponding to the absorption maximum of uric acid and creatinine. Uric acid and creatinine could be determined in less than 5 min by directly injecting plasma diluted fivefold; use of a precolumn eliminated the need for deproteinization. We evaluated the precision, recovery, linearity, specificity, and limit of detection of the method and we checked for analytical interference by 37 currently used drugs. We compared results with those obtained by routine and reference methods.

A simple, rapid and reliable high performance liquid chromatography method for the simultaneous determination of creatinine and uric acid in plasma and urine

“…Reverse-phase with UV detection is frequently used because it is simple and effective and the costs are low. [15][16][17] The results measured by HPLC-UV have been proved in good agreement with those measured by isotope dilution mass spectrometry (IDMS), a recommended reference method for Cr quantitation, 18 and IDMS based measurement such as gas chromatography-IDMS. 19 The Laboratory Working Group of National Kidney Disease Education Program concludes that HPLC appears to provide an excellent designated comparison method because it has greater analytical specicity than conventional methods.…”

“…Clean-up of the sample prior to injection is essential for a reliable, stable HPLC method. 24 The ways to obtain sample clean-up include ltration; 21,[25][26][27] solid-phase extraction with a special cartridge; 28 employing a pre-column 15 or a pre-column combined with a column switching technique; 16,22,23 using protein precipitants, such as perchloric acid (HClO 4 ), 29 trichloroacetic acid (TCA), 30 methanol (CH 3 OH), 3,31 acetonitrile 32 and acetone 33 etc. The ltration and solid-phase extraction procedures are laborious and the costs involved are high.…”

“…When a pre-column was used to keep proteins from reaching the analytical column, proteins accumulated on the pre-column, which when indicated by an increase in column pressure has to be replaced. The analytical column needed to be washed with distilled water and reconditioned with methanol aer each run 15 to avoid being fouled by endogenous substances such as lipids, which would distort the chromatographic peak shape. 34 Pre-column combined with column switching is a complicated technique, which required a long analysis time.…”

MELANIN AND URATE ACT TO PREVENT ULTRAVIOLET DAMAGE IN THE INTEGUMENT OF THE SILKWORM, BOMBYX mori

“…To prepare uric acid stock standard solution (1 g/L), we dissolved 500 mg of uric acid (Sigma) and 375 mg of lithium carbonate in 500 ml warm distilled water. After complete dissolution, this solution was cooled at room temperature and then stored at –20°C (Zhiri et al, ). It was further diluted with 0.7 g/L lithium carbonate into the following concentrations: 200, 100, 50, 25, 12.5, and 6.25 mg/l.…”

Simultaneous determination of plasma creatinine, uric acid, kynurenine and tryptophan by high‐performance liquid chromatography: method validation and in application to the assessment of renal function

“…Several high‐performance liquid chromatography (HPLC) methods have been developed for the simultaneous determination of Cr and UA (Seki et al ., ; Yang, ; Zhao, ; Zhiri et al ., ) or KYN and TRP (Iizuka et al ., ; Laich et al ., ; Vignau et al ., ; Zhang et al ., ; Zhao et al ., ) in plasma or serum using a single mobile phase with constant elution. In reverse‐phase HPLC, the volume of organic solvent contained in the mobile phase for the separation of Cr and UA (Zhao, ) was much lower than that for the separation of KYN and TRP (Zhang et al ., ; Zhao et al ., ).…”