El-Naby Eman H
Narcotic Department, National Center for Social and Criminal Research, P. O. Zamalek Post, 11561, Cairo, Egypt.
Anal Sci. 2008;24(11):1409-14. doi: 10.2116/analsci.24.1409.
The construction and electrochemical response characteristics of poly(vinyl chloride) matrix ion-selective electrodes (ISEs) for dextromethorphan (DXM) hydrobromide are described. The membranes incorporate ion-association complexes of DXM with reineckate salt {[Cr(NH3)2(SCN)4]NH4} or phosphomolybdic acid [H3(PMo12O40)], as electroactive materials and dioctylphthalate or dibutylsebacate as a plasticizing solvent mediator. The sensors display a fast, stable and linear response with slopes of 54.4 to 59.5 mV/decade at pH 2.5-6.5 and a detection limit of 1.0 x 10(-6) M. Moreover, the sensors exhibit very good selectivity for DXM over opiate alkaloids, as well as organic and inorganic cations. The sensors proved to be useful for the determination of 5.0 x 10(-5)-1.0 x 10(-3) M DXM hydrobromide in pure as well as in dosage forms by direct potentiometry and standard addition methods. Determination of 5.0 x 10(-4) M DXM using the standard addition method and a sensor based on phosphomolybdate and dioctylphthalate shows an average recovery of 99.8% and a relative standard deviation (RSD) of 0.4%.
描述了用于氢溴酸右美沙芬（DXM）的聚氯乙烯基质离子选择电极（ISE）的构建及其电化学响应特性。这些膜包含DXM与雷氏盐{[Cr(NH3)2(SCN)4]NH4}或磷钼酸[H3(PMo12O40)]的离子缔合配合物作为电活性材料，以及邻苯二甲酸二辛酯或癸二酸二丁酯作为增塑溶剂介质。该传感器在pH 2.5 - 6.5范围内显示出快速、稳定且线性的响应，斜率为54.4至59.5 mV/十倍浓度变化，检测限为1.0×10(-6) M。此外，该传感器对DXM相对于阿片生物碱以及有机和无机阳离子具有非常好的选择性。通过直接电位法和标准加入法，该传感器被证明可用于测定纯品以及剂型中5.0×10(-5) - 1.0×10(-3) M的氢溴酸右美沙芬。使用标准加入法和基于磷钼酸盐和邻苯二甲酸二辛酯的传感器测定5.0×10(-4) M的DXM，平均回收率为99.8%，相对标准偏差（RSD）为0.4%。
