Safavi Afsaneh, Ahmadi Raheleh, Mahyari Farzaneh Aghakhani
Department of Chemistry, College of Sciences, Shiraz University, Shiraz, 71454, Iran,
Amino Acids. 2014 Apr;46(4):1079-85. doi: 10.1007/s00726-014-1668-4. Epub 2014 Jan 24.
A linear sweep voltammetric method is used for direct simultaneous determination of L-cysteine and L-cysteine disulfide (cystine) based on carbon ionic liquid electrode. With carbon ionic liquid electrode as a high performance electrode, two oxidation peaks for L-cysteine (0.62 V) and L-cysteine disulfide (1.3 V) were observed with a significant separation of about 680 mV (vs. Ag/AgCl) in phosphate buffer solution (pH 6.0). The linear ranges were obtained as 1.0-450 and 5.0-700 μM and detection limits were estimated to be 0.298 and 4.258 μM for L-cysteine and L-cysteine disulfide, respectively. This composite electrode was applied for simultaneous determination of L-cysteine and L-cysteine disulfide in two real samples, artificial urine and nutrient broth. Satisfactory results were obtained which clearly indicate the applicability of the proposed electrode for simultaneous determination of these compounds in complex matrices.
采用线性扫描伏安法，基于碳离子液体电极直接同时测定L-半胱氨酸和L-半胱氨酸二硫化物（胱氨酸）。以碳离子液体电极为高性能电极，在pH 6.0的磷酸盐缓冲溶液中，观察到L-半胱氨酸（0.62 V）和L-半胱氨酸二硫化物（1.3 V）的两个氧化峰，二者显著分离，分离度约为680 mV（相对于Ag/AgCl）。L-半胱氨酸和L-半胱氨酸二硫化物的线性范围分别为1.0 - 450 μM和5.0 - 700 μM，检测限分别估计为0.298 μM和4.258 μM。该复合电极用于同时测定两个人造尿液和营养肉汤实际样品中的L-半胱氨酸和L-半胱氨酸二硫化物。获得了令人满意的结果，清楚地表明了所提出的电极用于在复杂基质中同时测定这些化合物的适用性。
