双波长叠加分光光度法测定盐酸尼卡地平

目的：建立一种盐酸尼卡地平的双波长叠加分光光度测定方法。方法：在 pH 为3.4的Britton‐Robinson缓冲溶液中，曙红Y（EY）与适量的盐酸尼卡地平（NP? HCl）相互作用，在最大褪色波长516 n m和最大增色波长548 n m处测量吸光度ΔA。结果：褪色法和增色法的摩尔吸光系数（ε）分别为1.52×105 L／（mol?cm）和3.20×104 L／（mol?cm）。采用双波长叠加法测定时，ε提高到1.84×105 L／（mol?cm），检出限为26 ng／mL。结论：该法简便、快速、可靠，可用于市售盐酸尼卡地平缓释胶囊的含量测定。

Determination of Nicardipine Hydrochloride by Dual-wavelength Overlapping Spectrophotometry

Objective:To develop a dual‐wavelength overlapping spectrophotometry method for the determination of Nicardipine Hydrochloride(NP?HCl) .Methods:In a Britton‐Robinson buffer solution of pH 3.4 ,Eosin Y(EY) could interact with NP?HCl . The absorbance ΔA was measured at the maximum fading wavelength (516 nm) and the maximum coloring revealing wavelength (548 nm) .Results:The molar absorptivity (ε) of fading wavelength method and revealing wavelength were 1.52 × 105 L/(mol?cm) and 3.20 × 104 L/(mol?cm) ,respectively .Theεincreased to 1.84 × 105 L/(mol?cm) by using the dual‐wavelength overlapping spectrophotometry to determine the NP ? HCl ,detection limit of proposed method was found to be 26 ng/mL .Conclusion :The method is simple ,accurate and sensitive ,which can be applied to the determination of the content of commercial available nicardipine hydrochloride sustained release capsules .