Residual pesticides in grape leaves (Vitis vinifera L.) on the Egyptian market and human health risk.

A QuEChERS method, followed by GC-MS/MS and LC-MS/MS was used for determining more than 400 pesticide residues in grape leaves collected from the Egyptian markets during the 2021 summer season. Seventy-eight samples contained 36 pesticide residues of different chemical groups above the EU-MRLs. Fungicides were the most frequently detected pesticides (59%), followed by insecticides (35%) and herbicides (5%).Hazard Quotients and Hazard Indexes were calculated where the results showed that both do not pose any health risk to consumers. Furthermore, cumulative risk assessment parameters (cHI) according to pesticide chemical group were calculated, resulting in 0.06, 0.09, 0.20, 0.28, 0.7 and 1.1% for strobin, organophosphorus, neonicotinoid, pyrethroid, benzimidazole and azole compounds, respectively. Fungicides were the major contributors to cHI, above insecticides by a factor of 2.7. Hence, there is a need for continuous survey and monitoring to protects consumers from exposure to unauthorized substances such as carbendazim, benomyl and profenofos.

Enhanced removal of fifteen pesticide mixture by a single bacterial strain using response surface methodology and its application in raw milk.

PURPOSE: Environmental contamination with various pesticides accompanied by uncontrolled use contributes to severe ecological and health problems. Although extensive research was conducted on pesticides degradation, very few reports have demonstrated the degradation of mixed pesticides. Consequently, this study aimed to evaluate the removal efficacy of highly potent bacterial isolate for pesticide mixture under optimal culture conditions, followed by their application in milk. METHODS: Isolation and selection of bacterial isolates were performed from 40 milk samples by enrichment culture technique and were screened to obtain highly potent bacterial strain identified by 16 S rDNA analysis. The statistics-based experimental designs were applied to optimize the culture conditions towards the best degradation of pesticides mixture, followed by subsequent utilization in milk. The degradation ratio of pesticides was analyzed using gas chromatography-mass spectrometry. RESULTS: In this study, a bacterial strain S6A identified as Bacillus subtilis-mw1 efficiently eliminated environmental contaminants from different groups of pesticide residues. The statistical optimization showcased optimum settings that accomplished the highest pesticide mixture degradation (61.59 %). The application experiment manifested that degradation of pesticide mixtures of sterile milk (STM) was relatively faster than non-sterile milk (NSTM). CONCLUSIONS: The obtained results assist in eliminating environmental contamination with various groups of pesticide residues. Furthermore, it can be employed in reducing pesticide residues that cause milk contamination to increase safety and quality.Graphical abstract. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40201-021-00683-0.

QuEChERS Method Followed by Solid Phase Extraction Method for Gas Chromatographic-Mass Spectrometric Determination of Polycyclic Aromatic Hydrocarbons in Fish.

A gas chromatography equipped with mass spectrometer (GCMS) method was developed and validated for determination of 16 polycyclic aromatic hydrocarbons (PAHs) in fish using modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) method for extraction and solid phase extraction for sample cleanup to remove most of the coextract combined with GCMS for determination of low concentration of selected group of PAHs in homogenized fish samples. PAHs were separated on a GCMS with HP-5ms Ultra Inert GC Column (30 m, 0.25 mm, and 0.25 µm). Mean recovery ranged from 56 to 115%. The extraction efficiency was consistent over the entire range where indeno(1,2,3-cd)pyrene and benzo(g,h,i)perylene showed recovery (65, 69%), respectively, at 2 µg/kg. No significant dispersion of results was observed for the other remaining PAHs and recovery did not differ substantially, and at the lowest and the highest concentrations mean recovery and RSD% showed that most of PAHs were between 70% and 120% with RSD less than 10%. The measurement uncertainty is expressed as expanded uncertainty and in terms of relative standard deviation (at 95% confidence level) is ±12%. This method is suitable for laboratories engaged daily in routine analysis of a large number of samples.