共振散射光谱法测定多巴胺的分析应用研究

摘要

The interaction between I3-and malachite green (MG)and its application for determining trace dopamine by resonance light scattering(RLS) method were studied.It was found that malachite green could react with I3-to form an ion-association complex(MG(I3)2)with the composition ratio of 1 ∶ 2 by electrostatic forces in citric acid-sodium citrate buffer solution (pH 4.5),in the presence of polyvinyl alcohol(PVA) and p-octyl polyethylene glycol phenyl ether (OP).Dopamine could convert I3-to I-,resulting in the decrease of resonance light scattering intensity of the malachite green-I3-system.Based on this,a new simple method with high sensitivity and good repeatability was developed to determine dopamine by resonance light scattering.Under the optimal conditions,the calibration curve was linear in the range of 2.0 × 10-7-4.5 × 10-6 mol · L-1,with a correlation coefficient of 0.999 1 and a detection limit(3S/k)of 9.5 × 10-8 mol · L-1.The proposed method was used to determine dopamine in injection and human serum samples with mean recoveries of 100.1％-102.4％ and relative standard deviations of 0.41％-4.8％.%研究了I3-与孔雀石绿(MG)间的相互作用,并用于共振散射光谱法测定痕量多巴胺.在pH4.5的柠檬酸-柠檬酸钠缓冲液中,在聚乙烯醇(PVA)与聚乙二醇辛基苯基醚(OP)存在的条件下,孔雀石绿与I3-通过静电作用力生成络合比为1∶2的离子缔合物MG(I3)2,而多巴胺具有还原性,可将I3-还原成I-,从而导致I3--孔雀石绿体系的共振散射强度下降.据此建立了一种灵敏度高、重现性好、快速测定多巴胺的共振散射光谱新方法.在优化的实验条件下,多巴胺的线性范围为2.0×10-7～4.5 ×10-6 mol·L-1,相关系数(r)为0.9991;检出限(3S/k)为9.5 ×10-8 mol·L-1.将方法应用于针剂和人血清中多巴胺含量的测定,其加标回收率为100.1％～102.4％,相对标准偏差为0.41％ ～4.8％.