化学计量学-动力学分光光度法同时测定两种儿茶酚胺类物质

Chemometric assisted kinetic spectrophotometric method for simultaneous analysis two catecholamines

利用速差动力学分光光度法结合化学计量学对两种儿茶酚胺类物质进行同时测定。在pH=4.3的醋酸缓冲介质中,这两种儿茶酚胺类物质(多巴胺和肾上腺素)与Fe3+发生氧化还原反应,生成的Fe2+进而与邻菲啰啉络合生成桔红色物质。基于这一反应,并考虑到反应速率存在差异,提出了同时测定多巴胺和肾上腺素的新方法,实验发现该反应体系在510nm处有最大吸收峰,以该波长为检测波长,反应时间设置为400s,以此最佳实验条件,测得多巴胺和肾上腺素的线性范围分别为0.08～1.36,0.08～0.80mg.L-1,而检测限分别为0.05,0.02mg.L-1。由于测得的动力学光谱数据重叠比较严重,采用一阶导数光谱法结合化学计量学方法对重叠的动力学光谱数据进行解析,完成了多巴胺和肾上腺素的光谱法同时定量测定。

In this study,a chemometric-assisted kinetic spectrophotometric method has been developed for simultaneous analysis of trace amount of two catecholamines,dopamine and epinephrine.This method based on the difference in the kinetic rates of the reactions of analytes with a common oxidizing agent of tris（1,10-phenanthroline） and iron（III） complex（ferritin,[Fe（phen）3]3＋） at pH 4.3.The spectrophotometric-kinetic data were recorded from 0 s to 400 s at maximum absorption wavelength 510 nm,under the optimized experimental conditions.Linear ranges were obtained in the concentration of 0.08-1.36 and 0.08-0.8 mg·L-1 for dopamine and epinephrine,respectively,and their corresponding detection limits were 0.05 and 0.018 mg·L-1.The measured absorbance data obtained from the experiments were processed by chemometric methods,partial least squares（PLS）,principal component regression（PCR） and radial basis function-artifical neural networks（RBF-ANN）.The proposed method was successfully applied to determine the catecholamines in bovine serum and urine samples.