Guo Li, Zhang Yan, Li Quanmin
College of Chemistry and Environmental Science, Henan Normal University, Henan Key Laboratory for Environmental Pollution Control, Xinxiang, Henan 453007, P. R. China.
Anal Sci. 2009 Dec;25(12):1451-5. doi: 10.2116/analsci.25.1451.
In the present work, we developed a simple, sensitive and inexpensive method to determine dopamine hydrochloride using potassium ferricyanide-Fe(III) by spectrophotometry. The results show that Fe(III) is deoxidized to Fe(II) by dopamine hydrochloride at pH 4.0, and then Fe(II) reacts with potassium ferricyanide to form a soluble prussian blue (KFe(III)[Fe(II)(CN)6]). The absorbance of this product was monitored over time using a spectrophotometer at an absorption maximum of 735 nm, and the amount of dopamine hydrochloride could be calculated based on the absorbance. A good linear relationship of the concentration of dopamine hydrochloride versus absorbance was observed, and a linear regression equation of A = 0.022 + 0.16921C (microg mL(-1)) was obtained. Moreover, the apparent molar absorption coefficient for the indirect determination of dopamine hydrochloride was 3.2 x 10(4) L mol(-1) cm(-1). This described method has been used to determine dopamine hydrochloride in pharmaceutical, banana, urine and serum samples with satisfactory results.
在本研究中，我们开发了一种简单、灵敏且廉价的方法，通过分光光度法使用铁氰化钾-Fe(III)来测定盐酸多巴胺。结果表明，在pH 4.0时，盐酸多巴胺将Fe(III)还原为Fe(II)，然后Fe(II)与铁氰化钾反应形成可溶性普鲁士蓝（KFe(III)[Fe(II)(CN)6]）。使用分光光度计在735 nm的最大吸收波长下随时间监测该产物的吸光度，并且可以根据吸光度计算盐酸多巴胺的量。观察到盐酸多巴胺浓度与吸光度之间具有良好的线性关系，得到线性回归方程A = 0.022 + 0.16921C（μg mL(-1)）。此外，间接测定盐酸多巴胺的表观摩尔吸收系数为3.2 x 10(4) L mol(-1) cm(-1)。所描述的方法已用于测定药物、香蕉、尿液和血清样品中的盐酸多巴胺，结果令人满意。
