Mayer W J, McCarthy J P, Greenberg M S
J Chromatogr Sci. 1979 Dec;17(12):656-60. doi: 10.1093/chromsci/17.12.656.
A system for the determination of oxalic acid in human urine using ion exchange-ion pair, high performance liquid chromatography with electrochemical detection (HPLCEC) is described. Urine is acidified with HCl, and excess CaCl2 is added to precipitate oxalate ion. The precipitate is isolated, redissolved in dilute sulfuric acid, and separated on a strong cation exchange column using an acetic acid-solium acetate-tetrabutylammonium tetrafluoroborate mobile phase adjusted to pH 2.8. Using an electrochemical detector at 1.25 volts vs. the saturated calomel electrode (SCE), oxalic acid exhibits a linear dynamic range from 1 to 1000 mg/liter with a detection limit of 0.1 mg/liter. Quantitative data are obtained by the method of standard addition in the clinically significant range from 5 to 40 mg/liter. Percentage recovery for spiked urine samples was 97.8% with a relative standard deviation of 2.5%.
描述了一种使用离子交换-离子对、带电化学检测的高效液相色谱法（HPLCEC）测定人尿中草酸的系统。尿液用盐酸酸化，并加入过量氯化钙使草酸根离子沉淀。分离出沉淀，将其重新溶解在稀硫酸中，并使用调整至pH 2.8的乙酸-乙酸钠-四丁基四氟硼酸铵流动相在强阳离子交换柱上进行分离。使用相对于饱和甘汞电极（SCE）为1.25伏的电化学检测器，草酸的线性动态范围为1至1000毫克/升，检测限为0.1毫克/升。通过标准加入法在5至40毫克/升的临床显著范围内获得定量数据。加标尿样的回收率为97.8%，相对标准偏差为2.5%。
