Search

Triple quadrupole mass spectrometry was used for the direct, quick and quantitative determination of chlorpyrifos residue in bell peppers using the QuEChERS extraction method. The method was validated, and the parameters were confirmed to be within the regulated limits. The limit of detection was 2.6 [micro]g/kg with a linear dynamic range from 5 to 200 [micro]g/kg. The percent recoveries of fortified bell pepper samples at 5, 10, and 50 [micro]g/kg were 84.6, 99.9, and 98.5% with the relative standard deviations of 3.3, 1.8, and 0.6%, respectively. As a result, the bell pepper samples collected from markets in Ho Chi Minh city contained chlorpyrifos despite the fact that in 2019 the Ministry of Agriculture and Rural Development removed the pesticides containing chlorpyrifos from the list of pesticides permitted for use in Vietnam. This method is suitable for the determination of chlorpyrifos residue in bell peppers with high sensitivity, accuracy, good precision, rapid analysis, and high specificity in a complex matrix., Author(s): Van-Trong Nguyen [sup.1], Long-Ho Tran [sup.1] [sup.2], Thanh-Khue Van [sup.1], Dinh-Vu Le [sup.1] Author Affiliations: (1) grid.448730.c, 0000 0004 0518 008X, Faculty of Chemical Engineering, Industrial University of Ho [...]

The level of carboxyhemoglobin (CO-Hb) in the forensic blood sample is a critical evidence to the conclusion that the fatality was related to CO poisoning or other reason causing death. In this study, we validated the method for CO-Hb determination in blood using headspace gas chromatography-flame ionization detector (HS-GC/FID) for further application to the analysis of forensic samples. The liberated CO from CO-Hb was reduced to methane by a specific catalyst and then analyzed by GC-FID. The quantitative range for CO-Hb was from 2.5 to 100% with the limit of detection down to 0.5%. The average recovery at different levels of CO-Hb was from 96.8 to 98.5% with high repeatability and intermediate precision. The obtained parameters presented that the method was highly sensitive and accurate for CO-Hb determination in blood samples. The method was also applied to the analysis of 27 forensic samples that had the questionable cause of death. Eighteen samples were related to CO poisoning with the level of CO-Hb exceeding 15%. All the results demonstrated that this method could be applied for forensic diagnosis., Author(s): Dinh-Vu Le [sup.1], Minh-Thu Dang [sup.2] Author Affiliations: (1) grid.448730.c, 0000 0004 0518 008X, Faculty of Chemical Engineering, Industrial University of Ho Chi Minh City, , Go Vap, 70000, [...]