No abstract

The present study was carried out in the northeastern part of Bangladesh to investigate organochlorine pesticide (OCP) residues in and microbiological quality of dried barb (Puntius sophore). Samples were collected from both producers and retailers from December 2016 to April 2017. A control sample was also prepared in the laboratory with the same raw fish used by the producers to compare the results. Gas chromatography with electron capture detector (GC-ECD) was used to detect and quantify OCP residues. Six samples out of 27 (about 22%) were found to be contaminated with OCP residues. Among these six adulterated samples, four were from retailers and two from producers. Only aldrin was detected in four samples, and in the other two samples both aldrin + dieldrin and aldrin + endrin were detected. Aldrin was found in quantities between 0.332 and 0.967 ppm, dieldrin 0.762 ppm, and endrin 0.828 ppm. All these values were much higher than the maximum residual limit (MRL) of 0.1 ppm. Total plate count (TPC) of producer samples ranged from 5.3 ± 0.02 log cfu g−1 to 5.4 ± 0.03 log cfu g−1 and 6.2 ± 0.02 log cfu g−1 to 6.4 ± 0.02 log cfu g−1 for retailer samples and 5.0 ± 0.03 log cfu g−1 to 5.2 ± 0.04 log cfu g−1 for control samples. Fungal count ranged from 3.2 ± 0.04 log cfu g−1 to 3.5 ± 0.04 log cfu g−1, 3.4 ± 0.04 log cfu g−1 to 3.6 ± 0.03 log cfu g−1, and 2.2 ± 0.05 log cfu g−1 to 2.5 ± 0.03 log cfu g−1 for producer, retailer, and control samples, respectively. All the producer and retailer samples and one-third of the control samples were found to be contaminated with Escherichia coli, whereas Salmonella spp. were detected in amounts of 13.3% in producer samples and 20% in retailer samples and none in the control. In case of Vibrio spp., maximum count was found in retailer samples (13.3%), whereas producer and control samples showed none. The findings of the present study show that the presence of pesticides and poor microbiological quality of dried barb are alarming for consumers in Bangladesh and might cause prolonged disease and impending longstanding risk to human health.

The present study was aimed to validate an analytical method for the quantification of 19 organochlorine and 2 synthetic pyrethroid pesticide residues in water samples using modified quick, easy, cheap, effective, rugged and safe (QuEChERS) extraction and Gas Chromatography coupled with Electron Capture Detector (ECD). The selected pesticide residues were determined by inhouse validated method. The analytical method was validated by evaluating the accuracy, precision, linearity, limit of detection (LOD) and limit of quantification (LOQ). The average recoveries of the selected pesticides ranged from 78% to 117% with RSDr ≤ 12% in two fortification levels of 0.02 and 0.1 mg/L. The linearity was ≥0.995 for all of the selected pesticides. The LOD ranged from 0.003 to 0.006 mg/L and the LOQ was 0.02 mg/L for all the selected analytes. This method was applied satisfactorily for the residue analysis of 108 water samples collected from nine districts of Bangladesh. Among the analyzed samples, only 4 had cypermethrin residues (0.026 mg/L, 0.034 mg/L, 0.045 mg/L and 0.05 mg/L). The level of detected cypermethrin residues were above the WHO recommended guide line values of water quality.

A simple, sensitive and economical spectrophotometric method has been developed for the determination of zidovudine in commercial dosage forms. The method was based on the formation of chloroform extractable complex of zidovudine with wool fast blue. The absorbance of the extractable ion pair complex is measured at the wavelength of maximum absorbance 590 nm against the reagent blank treated similarly. Statistical analysis proves that the proposed methods are reproducible and selective for the estimation of zidovudine in bulk drug and in its tablet dosage form.

This study was initiated to develop an accurate analytical method for the determination of neonicotinoid and organophosphorus insecticide using Liquid Chromatography tandem Mass Spectrometry (LC-MS/MS). Several experiments were conducted to select the parent ion and precusor ion and based on this outcome, the analytical method for the determination of thiamethoxam and dimethoate using LC-MS/MS was developed. The heated electrospray ionization (HESI) mode was used to develop the method.  The linearity of the developed analytical method was very good and it was 0.998 for both of the selected pesticides. The optimization of MS/MS parameters has been done properly for both of the selected pesticides through direct infusion of 100 ug/L standard solutions. Asian Australas. J. Food Saf. Secur. 2022, 6 (2), 65-72