A LC-MS /MS method was developed for the determination of ten sulfonamides residues in milk.The MS was operated in the positive ion mode using multiple reaction monitoring.The protein of the sample was separated by ac...A LC-MS /MS method was developed for the determination of ten sulfonamides residues in milk.The MS was operated in the positive ion mode using multiple reaction monitoring.The protein of the sample was separated by acetonitrile.The extract was concentrated under the stream of nitrogen.The analytes were separated on a reversed-phase column of ZORBAX SB-C18(5 μm,4.6 mm×150 mm i.d.) by using methanol-acetonitrile-0.2% formic acid 10 mmol/L ammonium acetate solution as the mobile phase and gradient elution.The limits of detection were 0.5 and 1.0 μg/L,respectively,and the recoveries were between 91% and 102%.展开更多
This thesis developed a LC-ESI-TRAP-MS method for twelve β-lactam antibiotics residues in milk.The massspectrometer was operated in the positive ion mode using multiple reaction monitoring.The limit of detection is 1...This thesis developed a LC-ESI-TRAP-MS method for twelve β-lactam antibiotics residues in milk.The massspectrometer was operated in the positive ion mode using multiple reaction monitoring.The limit of detection is 1.0 and 2.0 μg/L.Overall recoveries were between 55.2% and 109.5%.展开更多
The effect of rare earths on the morphology and microstructure of eutectic carbides in M2 high speed steel was studied. The results showed that rare earths promoted the forrmation of fishbone-like M6C eutectic carbide...The effect of rare earths on the morphology and microstructure of eutectic carbides in M2 high speed steel was studied. The results showed that rare earths promoted the forrmation of fishbone-like M6C eutectic carbides, compared to plate-like M2C carbides in ingots without modification. The formation of M6C was expected to be caused by rare earth inclusions which acted effectively as the substratc for nucleation of M6C carbides during solidification. M2C and M6C eutectic carbides exhibited different stability during heating. M2C eutectic carbides were much less stable than M6C carbides, and decomposed at high temperatures, favoring the spheroidization and refmement of carbides inhigh speed steels.展开更多
文摘A LC-MS /MS method was developed for the determination of ten sulfonamides residues in milk.The MS was operated in the positive ion mode using multiple reaction monitoring.The protein of the sample was separated by acetonitrile.The extract was concentrated under the stream of nitrogen.The analytes were separated on a reversed-phase column of ZORBAX SB-C18(5 μm,4.6 mm×150 mm i.d.) by using methanol-acetonitrile-0.2% formic acid 10 mmol/L ammonium acetate solution as the mobile phase and gradient elution.The limits of detection were 0.5 and 1.0 μg/L,respectively,and the recoveries were between 91% and 102%.
文摘This thesis developed a LC-ESI-TRAP-MS method for twelve β-lactam antibiotics residues in milk.The massspectrometer was operated in the positive ion mode using multiple reaction monitoring.The limit of detection is 1.0 and 2.0 μg/L.Overall recoveries were between 55.2% and 109.5%.
基金Project supported by Fund of Transformation of Scientific and Technological Achievements from Jiangsu Province(BA2010139)the Opening Project of Jiangsu Key Laboratory of Advanced Metallic Materials(AMM201203)
文摘The effect of rare earths on the morphology and microstructure of eutectic carbides in M2 high speed steel was studied. The results showed that rare earths promoted the forrmation of fishbone-like M6C eutectic carbides, compared to plate-like M2C carbides in ingots without modification. The formation of M6C was expected to be caused by rare earth inclusions which acted effectively as the substratc for nucleation of M6C carbides during solidification. M2C and M6C eutectic carbides exhibited different stability during heating. M2C eutectic carbides were much less stable than M6C carbides, and decomposed at high temperatures, favoring the spheroidization and refmement of carbides inhigh speed steels.
