[Objective] A method was developed for the determination of 10 pyrethroids pesticide residues in rice by GC-MS-MS. [Method] Pyrethroids were extracted with acetonitrile, followed by a salting-out step with anhydrous m...[Objective] A method was developed for the determination of 10 pyrethroids pesticide residues in rice by GC-MS-MS. [Method] Pyrethroids were extracted with acetonitrile, followed by a salting-out step with anhydrous magnesium sulfate and sodium chloride, cleaned up by florisil solid phase extraction （SPE） cartridge, and determined by multiple reaction monitoring mode. [Result] The method showed good linearity over the range of 0.010-0.500 mg/L for 10 pyrethroid pesticide with correlation coefficients over 0.99. The detection limits were 0.005 -0.010 mg/kg. The method was validated by analyzing samples spiked with 0.05, 0.10, 0.20 mg/kg of 10 pyrethroid pesticides, respectively. The average recoveries in rice ranged from 75.0-115.5%, and the relative standard deviations （RSD） were between 3.9%-6.9%. [Conclusion] The method is easy, accurate and reliable, which can meet the requirement for the simultaneous determination and confirmation of pyrethroid pesticide residues in rice.展开更多
The acrylamide level of some commercial bread assortments have been evaluated. The influence of several flour types on the content of acrylamide in 14 samples of bread, purchased from 5 different suppliers from the ma...The acrylamide level of some commercial bread assortments have been evaluated. The influence of several flour types on the content of acrylamide in 14 samples of bread, purchased from 5 different suppliers from the market in Bucharest, Romania was studied. For all bread assortments which have been analyzed for acrylamide, the International Commission of Illumination （CIELab） parameters, L＊, a＊ and b＊ have been also measured in an attempt to correlate the colour of the final product with its acrylamide content. Determination of acrylamide in bread samples was performed by Gas Chromatography coupled with tandem Mass Spectrometry （GC-MS/MS）, using isotope dillution calibration after derivatization （bromination）. The results revealed that the acrylamide level vary between bread assortments of different brands and bread assortments of same brand, but different lots. In the case of commercial bread samples, the use of whole wheat flours lead to formation of higher quantity in acrylamide （165.53 μg/kg）, compared to the use of white wheat flours （28.02μg/kg）.展开更多
文摘[Objective] A method was developed for the determination of 10 pyrethroids pesticide residues in rice by GC-MS-MS. [Method] Pyrethroids were extracted with acetonitrile, followed by a salting-out step with anhydrous magnesium sulfate and sodium chloride, cleaned up by florisil solid phase extraction （SPE） cartridge, and determined by multiple reaction monitoring mode. [Result] The method showed good linearity over the range of 0.010-0.500 mg/L for 10 pyrethroid pesticide with correlation coefficients over 0.99. The detection limits were 0.005 -0.010 mg/kg. The method was validated by analyzing samples spiked with 0.05, 0.10, 0.20 mg/kg of 10 pyrethroid pesticides, respectively. The average recoveries in rice ranged from 75.0-115.5%, and the relative standard deviations （RSD） were between 3.9%-6.9%. [Conclusion] The method is easy, accurate and reliable, which can meet the requirement for the simultaneous determination and confirmation of pyrethroid pesticide residues in rice.
文摘The acrylamide level of some commercial bread assortments have been evaluated. The influence of several flour types on the content of acrylamide in 14 samples of bread, purchased from 5 different suppliers from the market in Bucharest, Romania was studied. For all bread assortments which have been analyzed for acrylamide, the International Commission of Illumination （CIELab） parameters, L＊, a＊ and b＊ have been also measured in an attempt to correlate the colour of the final product with its acrylamide content. Determination of acrylamide in bread samples was performed by Gas Chromatography coupled with tandem Mass Spectrometry （GC-MS/MS）, using isotope dillution calibration after derivatization （bromination）. The results revealed that the acrylamide level vary between bread assortments of different brands and bread assortments of same brand, but different lots. In the case of commercial bread samples, the use of whole wheat flours lead to formation of higher quantity in acrylamide （165.53 μg/kg）, compared to the use of white wheat flours （28.02μg/kg）.
