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
Pesticides having different structures and biological activities are widely used for agricultural and non-agricultural purposes throughout the world. Monitoring of pesticides in water contribute to the protection of h...Pesticides having different structures and biological activities are widely used for agricultural and non-agricultural purposes throughout the world. Monitoring of pesticides in water contribute to the protection of human health and the protection of environment too. Analysis of a big number of water samples each year is revealed a clear image for pollution by pesticides. Twenty-four pesticides are monitored in drinking, surface and ground waters of Cyprus according to the European legislation. During the last 4 years (2013-2016) 2860 samples were analysing using two different techniques of extraction and determination. Pesticides were separated at two groups according to their polarity and stability and determined using GC/MS and UPLC/MS/MS. The limit of quantification is 0.01 μg/L for those determined with UPLC/MS/MS and 0.01 - 0.03 μg/L for those determined with GC/MS. The results revealed that only 1.5% of the samples analysed found to contain some of these compounds at concentration over the limit of quantification. Only nine of the pesticides were found at the samples and those with the highest frequency were Chloropyrifos, Prosulfocarb and Simazine.展开更多
目的:建立中药材中8种真菌毒素的超高效液相色谱—串联质谱检测方法。方法:样品经粉碎过筛后用乙腈水溶液提取,经多功能净化柱Pribo Fast 100进行净化,采用XTerra MS C18色谱柱进行分离,以20mmol/L乙酸铵溶液和乙腈梯度洗脱,利用超高效...目的:建立中药材中8种真菌毒素的超高效液相色谱—串联质谱检测方法。方法:样品经粉碎过筛后用乙腈水溶液提取,经多功能净化柱Pribo Fast 100进行净化,采用XTerra MS C18色谱柱进行分离,以20mmol/L乙酸铵溶液和乙腈梯度洗脱,利用超高效液相色谱—串联质谱进行分析。结果:8种真菌毒素在测定浓度范围内线性关系良好,各组分相关系数R2> 0. 998,加标回收率范围72. 1%~92. 8%,方法精密度范围6. 3%~12. 2%,测定各组分真菌毒素定量限范围1. 2~2. 0μg/kg。结论:方法前处理过程简洁、灵敏度高、重现性好,适用于中药材中8种真菌毒素的测定。展开更多
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Pesticides having different structures and biological activities are widely used for agricultural and non-agricultural purposes throughout the world. Monitoring of pesticides in water contribute to the protection of human health and the protection of environment too. Analysis of a big number of water samples each year is revealed a clear image for pollution by pesticides. Twenty-four pesticides are monitored in drinking, surface and ground waters of Cyprus according to the European legislation. During the last 4 years (2013-2016) 2860 samples were analysing using two different techniques of extraction and determination. Pesticides were separated at two groups according to their polarity and stability and determined using GC/MS and UPLC/MS/MS. The limit of quantification is 0.01 μg/L for those determined with UPLC/MS/MS and 0.01 - 0.03 μg/L for those determined with GC/MS. The results revealed that only 1.5% of the samples analysed found to contain some of these compounds at concentration over the limit of quantification. Only nine of the pesticides were found at the samples and those with the highest frequency were Chloropyrifos, Prosulfocarb and Simazine.
