高效液相色谱法测定出口腐植酸钾中缩二脲的含量

Determination of Biuret in Export Potassium Humate by High Performance Liquid Chromatography

本研究建立了出口腐植酸钾中缩二脲含量检测的高效液相色谱分析方法。本方法以硫酸锌和氢氧化钾生成絮凝沉淀净化腐植酸钾,采用C18色谱柱(4.6 mm×250 mm,5.0μm),以磷酸二氢钾溶液+甲醇(95+5)为流动相,测定波长为200 nm,外标法定量。结果显示,当称样量为0.5 g时,检出限(LOD)和定量限(LOQ)分别为0.003%和0.01%,在0.01~0.2 mg/mL范围内线性相关系数大于0.999,3个上机浓度水平添加平均回收率为100.0%~104.0%,相对标准偏差(RSD)为1.8%~2.0%(n=6)。该方法准确、简便,可用于出口腐植酸钾中缩二脲的测定,填补了非无机肥料中缩二脲含量的检测方法的空白,为海关执法提供技术支撑。

In this study a high performance liquid chromatography analytical method for the determination of biuret content in export potassium humate was established.Potassium humate was purified by flocculation precipitation of zinc sulfate and potassium hydroxide.HPLC Column C18(4.6 mm×250 mm,5.0μm)was used as mobile phase with potassium dihydrogen phosphate solution+methanol(95+5).The measurement wavelength was 200 nm,and the external standard method was used for quantification.The experimental results showed that when the sample weight was 0.5 g,the limit of detection(LOD)and limit of quantitation(LOQ)was 0.003%and 0.01%,respectively.The linear correlation coefficients were more than 0.999 in the range of 0.01 to 0.2 mg/mL.The average recoveries of the three mass concentration levels were in the range of 100.0%to 104.0%,with the relative standard deviation(RSD)in the range of 1.8%to 2.0%(n=6).The method is accurate and simple,and can be used for the determination of biuret in export potassium humate.It fills the blank of the detection of biuret in non-inorganic fertilizers,and provides technical support for Customs law enforcement.