Department of Analytical Chemistry, Faculty of Chemistry and Technology, University of Split, Ruđera Boškovića 35, 21000 Split, Croatia.
Department of Chemistry, Faculty of Science and Education, University of Mostar, Matice hrvatske bb, 88000 Mostar, Bosnia and Herzegovina.
Molecules. 2021 Nov 11;26(22):6826. doi: 10.3390/molecules26226826.
A new flow injection spectrophotometric method for the determination of -acetyl-l-cysteine ethyl ester (NACET) was developed and validated. The method is based on the reduction of Cu(II)-ligand complexes to chromophoric Cu(I)-ligand complexes with the analyte. The studied ligands were neocuproine (NCN), bicinchoninic acid (BCA) and bathocuproine disulfonic acid (BCS). The absorbance of the Cu(I)-ligand complex was measured at 458, 562 and 483 nm for the reactions of NACET with NCN, BCA and BCS, respectively. The method was validated in terms of linear dynamic range, limit of detection and quantitation, accuracy, selectivity, and precision. Experimental conditions were optimized by a univariate method, yielding linear calibration curves in a concentration range from 2.0 × 10 mol L to 2.0 × 10 mol L using NCN; 2.0 × 10 mol L to 1.0 × 10 mol L using BCA and 6.0 × 10 mol L to 1.2 × 10 mol L using BCS. The achieved analytical frequency was 90 h for all three ligands. The method was successfully employed for NACET determination in pharmaceutical preparations, indicating that this FIA method fulfilled all the essential demands for the determination of NACET in quality control laboratories, as it combined low instrument and reagent costs with a high sampling rate.
一种新的流动注射分光光度法用于测定 -乙酰-l-半胱氨酸乙酯（NACET）被开发并验证。该方法基于分析物将 Cu(II)-配体络合物还原为显色的 Cu(I)-配体络合物。研究的配体是新铜试剂（NCN）、双缩脲酸（BCA）和 3,5-二溴-4-羟基苯磺酸（BCS）。与 NCN、BCA 和 BCS 反应时，Cu(I)-配体络合物的吸光度分别在 458、562 和 483nm 处测量。该方法在线性动态范围、检测限和定量限、准确度、选择性和精密度方面进行了验证。通过单变量方法优化实验条件，使用 NCN 时在 2.0×10-6mol L 至 2.0×10-6mol L 浓度范围内得到线性校准曲线；使用 BCA 时在 2.0×10-6mol L 至 1.0×10-6mol L 浓度范围内得到线性校准曲线；使用 BCS 时在 6.0×10-6mol L 至 1.2×10-6mol L 浓度范围内得到线性校准曲线。所有三种配体的分析频率均为 90h。该方法成功用于药物制剂中 NACET 的测定，表明该 FIA 方法满足质量控制实验室中 NACET 测定的所有基本要求，因为它结合了低仪器和试剂成本与高采样率。
