Departamento de Química Analítica, Facultad de Ciencias, Universidad de Cádiz, 11510 Puerto Real, Cádiz, Spain.
Talanta. 2012 Jan 30;89:448-54. doi: 10.1016/j.talanta.2011.12.061. Epub 2011 Dec 28.
Sonogel-Carbon electrode (SngCE) modified with bentonite (BENT) shows an interesting alternative electrode to be used in the determination of 1,4-benzodiazepines by square wave adsorptive cathodic stripping voltammetry (SWAdCSV). Diazepam (DZ) and chlordiazepoxide hydrochloride (CPZ), were determined using SngCE modified by 5% BENT. An electrochemical study of different parameters (such as pH, buffer type, ionic strength, accumulation potential, scan rate, and accumulation time) which affect the determination of DZ and CPZ is reported. Linear concentration ranges of 0.028-0.256 μg mL(-1) DZ (r=0.9997) and 0.034-0.302 μg mL(-1) CPZ (r=0.9997) are successfully obtained after an accumulation time of 60s. The quantification and detection limits were calculated to be 14.0 and 4.0 ng mL(-1) for DZ, and 16.0 and 5.0 ng mL(-1) for CPZ, respectively. The surface of the proposed electrode was characterized by scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDAX). The developed method was applied to the analysis of commercially available tablets and human urine real samples. Analysis was performed with better precision, very low detection limits, and faster than previously reported voltammetric techniques.
膨润土修饰的声凝胶-碳电极（SngCE）作为一种很有前途的替代电极，可用于通过方波吸附阴极溶出伏安法（SWAdCSV）测定 1,4-苯并二氮杂卓。使用 5%膨润土修饰的 SngCE 来测定地西泮（DZ）和盐酸氯氮䓬（CPZ）。报道了影响 DZ 和 CPZ 测定的不同参数（如 pH、缓冲液类型、离子强度、积累电位、扫描速率和积累时间）的电化学研究。在 60s 的积累时间后，成功获得了 DZ 的线性浓度范围为 0.028-0.256μg mL(-1)（r=0.9997）和 CPZ 的线性浓度范围为 0.034-0.302μg mL(-1)（r=0.9997）。DZ 的定量和检测限分别计算为 14.0 和 4.0ng mL(-1)，CPZ 的定量和检测限分别计算为 16.0 和 5.0ng mL(-1)。通过扫描电子显微镜（SEM）和能谱分析（EDAX）对提出的电极表面进行了表征。所开发的方法已应用于市售片剂和人尿实际样品的分析。与以前报道的伏安技术相比，该方法具有更好的精密度、更低的检测限和更快的分析速度。
