This paper describes a simple, rapid and sensitive liquid chromatography tandem mass spectrometry assay for the determination of duloxetine in human plasma. A duloxetine stable labeled isotope （duloxetine ds） was us...This paper describes a simple, rapid and sensitive liquid chromatography tandem mass spectrometry assay for the determination of duloxetine in human plasma. A duloxetine stable labeled isotope （duloxetine ds） was used as an internal standard. Analyte and the internal standard were extracted from 100 btL of human plasma via solid phase extraction technique using Oasis HLB cartridges. The chromatographic separation was achieved on a Cl8 column by using a mixture of acetonitrile 5 mM ammonium acetate buffer （83：17, v/v） as the mobile phase at a flow rate of 0.9 mL/min. The calibration curve obtained was linear （r2≥0.99） over the concentration range of 0.05 101 ng/mL. Multiple-reaction monitoring mode （MRM） was used for quantification of ion transitions at rn/z 298.3/154.1 and 303.3/159.1 for the drug and the internal standard, respectively. Method validation was performed as per FDA guidelines and the results met the acceptance criteria. A run time of 2.5 min for each sample made it possible to analyze more than 300 plasma samples per day. The proposed method was found to be applicable to clinical studies.展开更多
The quantitative estimation of amikacin （AMK） in AMK sulfate injection samples is reported using FTIR-derivative spectrometric method in a continuous flow system. Fourier transform of mid-IR spectra were recorded wi...The quantitative estimation of amikacin （AMK） in AMK sulfate injection samples is reported using FTIR-derivative spectrometric method in a continuous flow system. Fourier transform of mid-IR spectra were recorded without any sample pretreatment. A good linear calibration （r40.999, %RSDo 2.0） in the range of 7.7-77.0 mg/mL was found. The results showed a good correlation with the manufacturer＇s and overall they all fell within acceptable limits of most pharmacopoeial monographs on AMK sulfate.展开更多
The comparison of solid phase extraction（SPE） for the preconcentration and isolation of polyphenols in tobacco samples was carried out by ultra-high performance liquid chromatography/tandem mass spectrometry （UPLC/...The comparison of solid phase extraction（SPE） for the preconcentration and isolation of polyphenols in tobacco samples was carried out by ultra-high performance liquid chromatography/tandem mass spectrometry （UPLC/MS/MS） and multivariate analysis.Several adsorbing materials of SPE（C18,NH2,SAX and OASIS） were investigated.It was found that the C18 and OASIS cartridges can not only speed up the purification process,but also simplify the SPE operation.A UPLC/MS/MS was used for the determination of polyphenols in tobacco samples after purification.All analytes were separated and determined in 2min.The limit of detection was 0.05 ng/mL.Cluster analysis（CA） and principal component analysis（PCA） were used for the analysis of 4 varieties（flue-cured tobacco,oriental tobacco,sun-cured tobacco and burley） in order to interpret the effect of planting and machining process on the concentration of polyphenols.The different types of tobacco samples could be easily clustered by CA.PCA on the chemical composition of tobacco resulted in two principal components（PCs） that take 84.2% of the total variance.The PCA and CA indicate that the polyphenols can be used for distinguishing tobacco types.展开更多
In the present method of trace elements wire has been developed work, a new preconcentration by adsorption onto a niobium for electrothermal atomization atomic absorption spectrometry （ETAAS） with a tungsten tube at...In the present method of trace elements wire has been developed work, a new preconcentration by adsorption onto a niobium for electrothermal atomization atomic absorption spectrometry （ETAAS） with a tungsten tube atomizer. Detection limits （pg. mL-1） by this method combined with ETAAS were 45 for bismuth, 7.0 for cadmium, 20 for copper, 1.3 for gold, 36 for lead, 65 for manganese, 9.5 for rhodium and 19 for silver.展开更多
文摘This paper describes a simple, rapid and sensitive liquid chromatography tandem mass spectrometry assay for the determination of duloxetine in human plasma. A duloxetine stable labeled isotope （duloxetine ds） was used as an internal standard. Analyte and the internal standard were extracted from 100 btL of human plasma via solid phase extraction technique using Oasis HLB cartridges. The chromatographic separation was achieved on a Cl8 column by using a mixture of acetonitrile 5 mM ammonium acetate buffer （83：17, v/v） as the mobile phase at a flow rate of 0.9 mL/min. The calibration curve obtained was linear （r2≥0.99） over the concentration range of 0.05 101 ng/mL. Multiple-reaction monitoring mode （MRM） was used for quantification of ion transitions at rn/z 298.3/154.1 and 303.3/159.1 for the drug and the internal standard, respectively. Method validation was performed as per FDA guidelines and the results met the acceptance criteria. A run time of 2.5 min for each sample made it possible to analyze more than 300 plasma samples per day. The proposed method was found to be applicable to clinical studies.
基金the CDCHTA of the University of Los Andes for providing financial support through several approved projectsthe National Fund for Science, Technology and Innovation (FONACIT) of Venezuelan Ministry of Science and Technology for providing financial support, SPE 112–370 and Project G-2005000641
文摘The quantitative estimation of amikacin （AMK） in AMK sulfate injection samples is reported using FTIR-derivative spectrometric method in a continuous flow system. Fourier transform of mid-IR spectra were recorded without any sample pretreatment. A good linear calibration （r40.999, %RSDo 2.0） in the range of 7.7-77.0 mg/mL was found. The results showed a good correlation with the manufacturer＇s and overall they all fell within acceptable limits of most pharmacopoeial monographs on AMK sulfate.
基金Supported by the Foundation of State Tabacco Monopoly Bureau(China) in Research Project(No.110200902008)
文摘The comparison of solid phase extraction（SPE） for the preconcentration and isolation of polyphenols in tobacco samples was carried out by ultra-high performance liquid chromatography/tandem mass spectrometry （UPLC/MS/MS） and multivariate analysis.Several adsorbing materials of SPE（C18,NH2,SAX and OASIS） were investigated.It was found that the C18 and OASIS cartridges can not only speed up the purification process,but also simplify the SPE operation.A UPLC/MS/MS was used for the determination of polyphenols in tobacco samples after purification.All analytes were separated and determined in 2min.The limit of detection was 0.05 ng/mL.Cluster analysis（CA） and principal component analysis（PCA） were used for the analysis of 4 varieties（flue-cured tobacco,oriental tobacco,sun-cured tobacco and burley） in order to interpret the effect of planting and machining process on the concentration of polyphenols.The different types of tobacco samples could be easily clustered by CA.PCA on the chemical composition of tobacco resulted in two principal components（PCs） that take 84.2% of the total variance.The PCA and CA indicate that the polyphenols can be used for distinguishing tobacco types.
文摘In the present method of trace elements wire has been developed work, a new preconcentration by adsorption onto a niobium for electrothermal atomization atomic absorption spectrometry （ETAAS） with a tungsten tube atomizer. Detection limits （pg. mL-1） by this method combined with ETAAS were 45 for bismuth, 7.0 for cadmium, 20 for copper, 1.3 for gold, 36 for lead, 65 for manganese, 9.5 for rhodium and 19 for silver.
