碳纳米管修饰电极安培检测器离子色谱法测定儿茶酚胺类化合物

Determination of catecholamines by electrochemical modified ion chromatography

目的用碳纳米管修饰电极安培检测器离子色谱方法测定儿茶酚胺类化合物,为建立一种测定方法简单、灵敏度大大提高的分析测试方法提供依据。方法本实验采用离子色谱分离、碳纳米管修饰电极、直流安培检测,Dionex Ion Pac CS12分离柱(2 mm×250 mm)和Dionex Ion Pac CG12保护柱(2 mm×50 mm),以10 mmol/L硫酸溶液-10%乙腈溶液为淋洗液测定儿茶酚胺类化合物。结果该方法具有良好的重现性、线性关系和较低的检测限。修饰前被测物的检出限为0.000 3 mg/L^0 007 2 mg/L,修饰后的检出限为0.000 04 mg/L^0.000 09 mg/L,样品测定的回收率为96%~102%。结论该方法的准确度、精密度均较好,可以满足分析测试的要求。采用碳纳米管修饰电极测定,使峰高和峰面积都显著提高,从而大大提高了检测的灵敏度,是一种简便快速、分离效果良好的分析方法。

Objective An electrochemical modified ion chromatography method was established for the determination of catecholamine,so as to offer basis for establishing the method with simpleness and sensitivity great improved. Methods In this study,the ion chromatographic separation,carbon nanotube modified electrode,DC amperometric detection,Dionex Ion Pac CS12 separation column（ 2 mm × 250 mm） and Dionex Ion Pac CG12 protective column（ 2 mm × 50 mm） were adopted,with10 mmol / L sulfuric acid solution-10% acetonitrile solution as eluent to determine catecholamines. Results With this method,good linear relationship,sensitivity and reproducibility and lower detection limit were obtained. Before electrochemical modification,detection limit was among 0. 000 3 mg / L-0. 007 2 mg / L,and after that,the detection limit was among 0. 000 04 mg / L-0. 000 09 mg / L. And the recovery rate of catecholamine was among 96%-102%. Conclusion The test results show that the method accuracy and precision are better,meet the test requirements analysis. The adoption of carbon nanotube modified electrode makes the peak height and peak area significantly increased,thus,which greatly improved the detection sensitivity,indicating that it is a simple and rapid analysis method with good separation results.