Ultrasound-assisted dispersive liquid-liquid microextraction followed by ion mobility spectrometry for the simultaneous determination of bendiocarb and azinphos-ethyl in water, soil, food and beverage samples.

A sensitive and fast ultrasound-assisted dispersive liquid-liquid microextraction procedure combined with ion mobility spectrometry has been developed for the simultaneous extraction and determination of bendiocarb and azinphos-ethyl. Experimental parameters affecting the analytical performance of the method were optimized: type and volume of extraction solvent (chloroform, 150 µL), pH (9.0), type and volume of buffer (ammonium buffer pH = 9.0, 4.5 mL) and extraction time (3.0 min). Under optimum conditions, the linearity was found to be in the range of 2-40 and 6-100 ng/mL and the limits of detection (LOD) were 1.04 and 1.31 ng/mL for bendiocarb and azinphos-ethyl, respectively. The method was successfully validated for the analysis of bendiocarb and azinphos-ethyl in different samples such as waters, soil, food and beverage samples.

Application of cation-modified sulfur nanoparticles as an efficient sorbent for separation and preconcentration of carbamazepine in biological and pharmaceutical samples prior to its determination by high-performance liquid chromatography.

A simple and rapid solid phase extraction procedure using a mini-column packed with modified sulfur nanoparticles as a new, efficient and reusable sorbent has been developed for the preconcentration of carbamazepine prior to its determination by high performance liquid chromatography. This method is based on the retention of carbamazepine by modified sulfur nanoparticles which are quite efficient for fast adsorption and desorption of carbamazepine. An HPLC system including C18, 250×4.6mm column, methanol-acidic water (pH=2.6 by acetic acid) (60:40) as mobile phase and UV detector (λ=276nm) was used. The effects of multiple experimental conditions such as the effect of pH, type and volume of buffer, type and volume of eluent, sample and eluent flow rate, sorbent amount and interfering ions, on the analytical performance of the method were investigated. The calibration curve was linear in the range of 0.5-200ngmL-1 and LOD of the proposed method was found to be 0.16ngmL-1. The procedure was successfully applied for the determination of carbamazepine in pharmaceutical samples, human plasma and breast milk.