研究发现,在碱性条件下,邻苯二甲醛和β-巯基乙醇组合试剂可与多巴胺发生化学反应生成异吲哚类化合物。当用340nm光激发时产生462nm的荧光,且荧光强度与多巴胺含量呈良好的线性关系,从而建立了一种可视化荧光检测多巴胺的新方法。在pH9.8的H3BO3-NaOH缓冲条件下,检测的线性范围为5.2×10^-8~1.7×10^-5mol/L,相关系数为0.9993,检出限(3σ)为4.1×10~mol/L。对7.0×10^-6mol/L的多巴胺进行11次平行测定,其相对标准偏差为1.4%。方法用于盐酸多巴胺注射液含量的分析,平均加标回收率为97.7%。以波长为365nm紫外灯激发多巴胺样品,可实现多巴胺可视化半定量检测。
A visual method for the determination of dopamine is described based on the fluorescence emission of a new isoindole compound formed by the reaction between dopamine and o-phthaldialdehyde-β-mercaptoethanol fluorogenic reagent in alkaline medium. A linear relationship has been obtained between the fluorescence intensity at 462 nm when excited by 340 nm and dopamine concentration in the range of 5.2 × 10^-8 - 1.7 ×10^-5 mol/L with the correlation coefficient of 0.9993 in borate buffer solution (pH = 9.8 ). The detection limit is 4.1 × 10^-8s moL/L (3σ), and the relative standard deviation is 1.4% ( c =7.0 × 10^-6 mol/L, n = 11 ). The recommended method has been used for analysis of the injection containing dopamine hydrochloride with the recovery of 97.7%. A visual semi-quantificational method of dopamine could be proposed under the excitation of an ultraviolet light source.