Evaluation of mesoporous silica nanomatrial for extraction of chlordiazepoxide from aqueous samples; central composite design

Chlordiazepoxide (CLD) belonging to benzodiazepines category has medicine properties such as antianxiety, sedative, anticonvulsant, and muscle relaxant. This drug inhibits monosynaptic and polysynaptic reflexes by inactivity neuronal transmitters or by blocking excitatory synaptic transmission. The drug may also directly depress motor nerve and muscle function [1]. For these reasons, the development of highly sensitive and selective methods for analysis of BDs in complicated matrices is of great interest to clinicians and forensic toxicologists[2]. A new extraction method, based on dispersive mesoporous silica-ultrasound assisted microextraction, was used for the preconcentration of the chlordiazepoxide (CLD) in the water samples prior to high performance liquid chromatography (HPLC). The properties mesoporous silica (MCF-NH2) nanomaterial are characterized by FT-IR, SEM, and BET. This nanomaterial showed great adsorptive ability towards the CLD. The effective variables such as pH, the amount of adsorbent (mg), adsorption time (min), and Volume of desorption solvent (mL) are investigated by central composite design (CCD) were combined by a desirability function (DF). At optimum conditions, the method has linear response over 0.004–10 µg mL−1 with detection limit between 0.005 µg mL−1 with relative standard deviations (RSDs) less than 5% (n=3). The method has been successfully applied for the determination of the CLD in the water samples.