Effect on human health by residues of commonly used pesticides in vegetables cultivation

People in Bangladesh are over scared for toxicity of vegetables & fruits because of the educational level of the farmers is not up to the mark, farmers apply pesticides randomly on agricultural fields without maintaining pre-harvest intervals and dose. The aim of this work was to study dissipation pattern of some pesticides in some vegetables kept at room temperature which represent market condition and to identify and quantify pesticides applied on some vegetables. By interviewing the farmers three commonly used pesticides; cypermethrin, chlorpyrifos and fenvalerate were sprayed in the farmer’s fields of the western part of Bangladesh. Samples were extracted by QuEChERS method, cleaned-up by adsorption chromatography technique, and analyzed by GC-ECD. Recoveries were found to be between 87-107% with RSD lower than 10% at three spiking levels. Matrix matched calibration curves were linear for all the analytes with r2 ≥ 0.99. LODs were found to be 0.01 mg/kg for cypermethrin and 0.002 mg/kg for both of fenvalerate and chlorpyrifos. The samples of same cultivar’s variety were purchased from the markets of Savar, Mymemsingh and Cumilla. Our finding showed only the presence of cypermethrin in tomato but the values were below MRL and no pesticide residue was found in eggplant.

A Review on Adsorbents In Chromatography

The Adsorption chromatography only differs from adsorption in how the process operates, not the principle of separation. For adsorption chromatography, the adsorbent is used as the stationary phase. The solute binds to the adsorbent via van der Waal forces and steric interactions. Since the adsorption sites are typical only on the outer surface of the stationary phase, fairly small particles are used as the stationary phase. The technique of chromatography used presently is limited to a few adsorbents and usually to non-aqueous systems, due to the difficulty of elution of the adsorbate. However, aqueous systems could be used if adsorbents were available which permitted adsorption and desorption to be controlled by pH adjustment. Adsorption is present in many natural physical, biological, and chemical systems and is widely used in industrial applications such as activated charcoal, capturing and using waste heat to provide cold water for air conditioning and other process requirements, synthetic resins, increase storage capacity of carbide-derived carbons for tunable nanoporous carbon and water purification.