石墨炉原子吸收法间接测定氨基酸注射液中游离氨基酸含量

采用Pd-Rh化学基体改进剂,建立了石墨炉原子吸收光谱法（GFAAS）间接测定游离氨基酸的新方法．本方法基于磷酸铜悬浮液与氨基酸发生络合反应生成铜-氨基酸络合物,铜络合物可以采用GFAAS进行测定,而后根据铜-氨基酸络合物中的铜与氨基酸的摩尔比,依据铜的浓度计算出氨基酸的浓度．实验考察了多种金属离子化合物与氨基酸的反应,最终选择了硫酸铜悬浮液．实验选择Pd-Rh化学基体改进剂做铜的稳定剂,热解温度可以达到1630℃．在最佳实验条件下,成功地测定了氨基酸注射液中游离氨基酸含量,回收率为92%～108%．

Indirect Determination of Free Amino Acids in Amino Acid Injection by Graphite Furnace Atomic Absorption Spectrometry

An indirect method has been developed for the determination of free amino acids by graphite furnace atomic absorption spectrometry (GFAAS) using RH-Pd chemical matrix modifier in this paper. The proposed method is based on the complex reaction of copper(Ⅱ) slurry in the form of copper phosphate with amino acid to form Cu(Ⅱ)-amino acid chelates. The copper as complex was determined by GFAAS and the amounts of free amino acids were calculated from the amount of copper. In this paper, the reactions of different metallic compounds with amino acid were investigated and copper phosphate slurry selected. The Pd-Rh chemical matrix modifier was used to stabilize copper in the graphite furnace and a pyrolysis temperature of 1 630 ℃ was obtained. The experimental conditions were optimized and the proposed method was successfully applied to the determination of free amino acids in amino acid injection samples with a recovery range of 92%～108%.