流动注射电化学发光法测定半胱氨酸和谷胱甘肽

Flow injection analysis of cysteine and glutathione based on luminol electrochemiluminescence

采用流动注射分析技术研究了半胱氨酸和谷胱甘肽对鲁米诺微弱电化学发光的增敏行为。对影响电化学发光的各因素进行了试验和探讨 ,提出了可能的反应机理 ,并建立一种电化学发光测定半胱氨酸和谷胱甘肽的新方法。半胱氨酸和谷胱甘肽的浓度在 1 .0× 1 0 - 6 mol/L～ 5 .0× 1 0 - 5 mol/L和 1 .0× 1 0 - 6mol/L～ 2 .0× 1 0 - 5 mol/L之间呈良好的线性关系 ,相关系数分别为 0 .993和0 998,检出限分别为 0 .67μmol/L和 0 .72 μmol/L。对 1 .0× 1 0 - 5mol/L的半胱氨酸和谷胱甘肽进行 1 1次平行测定 ,相对标准偏差分别为 4.5 %和 3.7%。

Luminol electrochemiluminescence (ECL) could be sensitized by cysteine (CySH) and glutathione (GSH), and was investigated with the flow injection analysis technique. The experimental parameters influencing the ECL intensity were studied in detail. The possible mechanism of the ECL reaction was also proposed. A new flow injection method for the determination of cysteine and glutathione based on the system was established under the optimal experimental conditions. The method allowed the determination in the ranges of 1.0×10 -6 ～5.0×10 -5 mol/L for CySH, and 1.0×10 -6 ～2.0×10 -5 mol/L for GSH with the detection limits of 0.67 μmol/L for CySH and 0.72 μmol/L for GSH, respectively. The relative standard deviation of eleven determinations was 4.5% for 1.0×10 -5 mol/L CySH and 3.7% for 1.0×10 -5 mol/L GSH, respectively.