Analysis of low molecular weight organic acids in several complex liquid biological systems via HPLC with switching detection wavelength

Abstract In this study, we established an effective method to determine the composition of low molecular weight organic acids (LMWOA) in several complex liquid biological systems via high performance liquid chromatography (HPLC) with switching detection wavelengths. A Shim-pack VP-ODS-C 18 column was used for the HPLC and the temperature was optimized to 30 °C. A mixture of 0.01 M KH 2 PO 4 and acetonitrile was used as the mobile phase and the column flow rate was 0.6 mL/min. Samples were eluted with a non-linear gradient. Compared with constant detection wavelength, the switching method improved the sensitivity and made all LMWOA analyzed at their maximum absorption wavelength. The linearity of the calibration curves for each organic acid in the desired concentration range was found to be good ( r 2  > 0.9991). The method is accurate and precise with recoveries ranging from 99.06% to 101.56% and both intra-day and inter-day variabilities (%RSD)