采用气相色谱-氢火焰离子化检测器法(gas chromatography with hydrogen flame ionization detection,GCFID)、顶空固相微萃取-气相色谱-质谱(headspace solid-phase microextraction coupled with gas chromatography-mass spectrometr...采用气相色谱-氢火焰离子化检测器法(gas chromatography with hydrogen flame ionization detection,GCFID)、顶空固相微萃取-气相色谱-质谱(headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry,HS-SPME-GC-MS)和电子鼻技术分析6种果酒中的挥发性成分,评价果酒风味轮廓特征的差异性。结果表明,GC-FID定量测定樱桃李酒,其中异戊醇、活性戊醇、β-苯乙醇含量最高,乙酸乙酯含量最低;木瓜酒中正丙醇、2,3-丁二醇、癸酸乙酯、乙酸含量最高; 3-羟基-2-丁酮含量在樱桃李酒中最高,山楂酒、甜橙酒中最少。HP-SPME-GC-MS鉴定果酒中挥发性物质94种,其中醇类23种,酯类43种,醛酮类10种,酸类8种,酚类2种,苯环类5种,烷烃类3种。山楂酒、菠萝酒、木瓜酒、甜橙酒、无花果酒和樱桃李酒中香气物质数量分别为34、44、45、45、33、47种。其中山楂酒、木瓜酒和无花果酒中未检出酚类、烷烃类物质。电子鼻对不同果酒香气的区分效果无重叠,W5S传感器区分果酒香气能力最强。比较而言,菠萝酒和樱桃李酒的口感更圆润,香气更愉悦,感官得分最高。展开更多
Mango fruit has a great national and international market, and Brazilian production is 1,900 thousand tons/year exporting to North America and Europe. However, the loss could occur during the production when it is aff...Mango fruit has a great national and international market, and Brazilian production is 1,900 thousand tons/year exporting to North America and Europe. However, the loss could occur during the production when it is affected by pests and climate conditions, so the increased use of chemical substances and their presence should be monitored. A task for governmental agencies, producers and food sales, attending the sanitary barriers requirements, is to distribute food free from contaminants, so laboratories involved in this type of work usually employ multi-residues analysis. The objective of this study was to evaluate the presence of pesticide residues in mango using QuEChERS method and mass spectrometry technique. Positive samples were compared with Brazilian maximum residues level （MRL） and the health risk exposure was evaluated using the acute dietary intake （ADI） parameter. A total of 20 samples were collected from January to March, in Sao Paulo city markets. The recoveries were in the range of 70% to 120%, and standard deviation was below 20%. The category of pesticides not permitted for the crop were found in l0 samples; eight samples presented pesticides below MRL and two samples above MRL for the fungicide procloraz. The ADI values were below 20% of ADI for an adult and the worst case was dimethoate with 69% of ADI for children. The time spent in monitoring studies and the viability of method chosen must be considered by pesticide residues laboratories during routine analysis of food quality control.展开更多
应用基于气相色谱-质谱联用(GC-MS)的代谢组学方法结合细胞周期实验,研究羽扇豆醇体外抑制人乳腺癌细胞MCF-7增殖的作用机理。代谢组学的研究结果表明:通过正交偏最小方差判别分析(OPLS-DA)可以很好地区分羽扇豆醇作用的MCF-7细胞代谢...应用基于气相色谱-质谱联用(GC-MS)的代谢组学方法结合细胞周期实验,研究羽扇豆醇体外抑制人乳腺癌细胞MCF-7增殖的作用机理。代谢组学的研究结果表明:通过正交偏最小方差判别分析(OPLS-DA)可以很好地区分羽扇豆醇作用的MCF-7细胞代谢谱与对照组细胞代谢谱,模型参数为:R2 Ycum=0.988,Q2 Ycum=0.964。VIP(variable importance in the projection)值大于1的差异代谢物进一步用t检验进行单位分析,选择t<0.05(VIP>1)的代谢物作为羽扇豆醇作用组的生物标志物,得到琥珀酸、磷酸、亮氨酸、异亮氨酸等11种代谢差异物。结合羽扇豆醇将细胞周期抑制在G1期这一现象,推测羽扇豆醇可能是主要抑制了三羧酸循环中的琥珀酰辅酶A的生成和底物磷酸化生成ATP的反应来抑制MCF-7细胞的增殖。本实验从代谢组学角度为乳腺癌抗肿瘤机制提供新的线索。展开更多
为了考察水产品中二甲苯麝香和酮麝香的残留量，建立了水产品中痕量二甲苯麝香和酮麝香测定的多重吸附同步净化（MASP）-气相色谱-质谱联用法（GC-MS）。以乙腈高速匀浆提取样品，应用 MASP 方法对样品同时进行提取、盐析和净化，并采用...为了考察水产品中二甲苯麝香和酮麝香的残留量，建立了水产品中痕量二甲苯麝香和酮麝香测定的多重吸附同步净化（MASP）-气相色谱-质谱联用法（GC-MS）。以乙腈高速匀浆提取样品，应用 MASP 方法对样品同时进行提取、盐析和净化，并采用 GC-MS 在选择离子监测（ SIM）模式下测定水产品中的痕量二甲苯麝香和酮麝香，以基质匹配标准溶液外标法定量。选用 DB-5 MS 石英毛细管柱（30 m×0.25 mm×0.25μm），采用电子轰击电离源，二甲苯麝香的选择监测离子为 m / z 282、297、265，酮麝香为 m / z 279、294、191。结果表明：在优化条件下，二甲苯麝香和酮麝香在1～100μg / kg 范围内线性良好，相关系数不低于0.999，检出限（S / N =3）为0.30μg / kg。明虾、花蛤和鳗鱼空白样品中1.0、2.0、10.0μg / kg 3个添加水平下二甲苯麝香和酮麝香的加标回收率为79％～104％，相对标准偏差（RSD）为1.6％～13.3％。本方法具有操作简便、快速、准确的特点，可用于水产品中痕量二甲苯麝香和酮麝香的日常检测。展开更多
The chemical composition of essential oils obtained from Artemisia herba-alba and Mentha pulegium were determined. The essential oils were analyzed by gas chromatography coupled with mass spectrometry （GC/MS）. Their...The chemical composition of essential oils obtained from Artemisia herba-alba and Mentha pulegium were determined. The essential oils were analyzed by gas chromatography coupled with mass spectrometry （GC/MS）. Their antibacterial activity was studied in vitro against three standard strains： E. coli ATCC 25922, Staphylococcus aureus ATCC 29213, Pseudomonas aeruginosa ATCC 27853, and five clinical strains： Enterobacter cloacae, Staphylococcus aureus, Pseudomonas pyocyanique, Enterococcus faecium, and E. coli. Nineteen constituents were identified in A. herba-alba essential oil representing 99.57% of the total composition The major component was α-thujone （59.07%）. The bacterial strains were inhibited at concentrations ranging from 1.25 μL/mL to 5μL/mL and killed at concentrations ranging from 1.25 μL/mL to 10 μL/mL. M. pulegium resulted in the identification of eighteen constituents representing 99.48% of the total composition. The main component was pulegone （78.07%）. The minimal inhibitory （MIC） and bactericidal （MBC） concentrations were ranging from 1.25 μL/mL to 2.5 μL/mL.展开更多
文摘采用气相色谱-氢火焰离子化检测器法(gas chromatography with hydrogen flame ionization detection,GCFID)、顶空固相微萃取-气相色谱-质谱(headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry,HS-SPME-GC-MS)和电子鼻技术分析6种果酒中的挥发性成分,评价果酒风味轮廓特征的差异性。结果表明,GC-FID定量测定樱桃李酒,其中异戊醇、活性戊醇、β-苯乙醇含量最高,乙酸乙酯含量最低;木瓜酒中正丙醇、2,3-丁二醇、癸酸乙酯、乙酸含量最高; 3-羟基-2-丁酮含量在樱桃李酒中最高,山楂酒、甜橙酒中最少。HP-SPME-GC-MS鉴定果酒中挥发性物质94种,其中醇类23种,酯类43种,醛酮类10种,酸类8种,酚类2种,苯环类5种,烷烃类3种。山楂酒、菠萝酒、木瓜酒、甜橙酒、无花果酒和樱桃李酒中香气物质数量分别为34、44、45、45、33、47种。其中山楂酒、木瓜酒和无花果酒中未检出酚类、烷烃类物质。电子鼻对不同果酒香气的区分效果无重叠,W5S传感器区分果酒香气能力最强。比较而言,菠萝酒和樱桃李酒的口感更圆润,香气更愉悦,感官得分最高。
文摘Mango fruit has a great national and international market, and Brazilian production is 1,900 thousand tons/year exporting to North America and Europe. However, the loss could occur during the production when it is affected by pests and climate conditions, so the increased use of chemical substances and their presence should be monitored. A task for governmental agencies, producers and food sales, attending the sanitary barriers requirements, is to distribute food free from contaminants, so laboratories involved in this type of work usually employ multi-residues analysis. The objective of this study was to evaluate the presence of pesticide residues in mango using QuEChERS method and mass spectrometry technique. Positive samples were compared with Brazilian maximum residues level （MRL） and the health risk exposure was evaluated using the acute dietary intake （ADI） parameter. A total of 20 samples were collected from January to March, in Sao Paulo city markets. The recoveries were in the range of 70% to 120%, and standard deviation was below 20%. The category of pesticides not permitted for the crop were found in l0 samples; eight samples presented pesticides below MRL and two samples above MRL for the fungicide procloraz. The ADI values were below 20% of ADI for an adult and the worst case was dimethoate with 69% of ADI for children. The time spent in monitoring studies and the viability of method chosen must be considered by pesticide residues laboratories during routine analysis of food quality control.
文摘应用基于气相色谱-质谱联用(GC-MS)的代谢组学方法结合细胞周期实验,研究羽扇豆醇体外抑制人乳腺癌细胞MCF-7增殖的作用机理。代谢组学的研究结果表明:通过正交偏最小方差判别分析(OPLS-DA)可以很好地区分羽扇豆醇作用的MCF-7细胞代谢谱与对照组细胞代谢谱,模型参数为:R2 Ycum=0.988,Q2 Ycum=0.964。VIP(variable importance in the projection)值大于1的差异代谢物进一步用t检验进行单位分析,选择t<0.05(VIP>1)的代谢物作为羽扇豆醇作用组的生物标志物,得到琥珀酸、磷酸、亮氨酸、异亮氨酸等11种代谢差异物。结合羽扇豆醇将细胞周期抑制在G1期这一现象,推测羽扇豆醇可能是主要抑制了三羧酸循环中的琥珀酰辅酶A的生成和底物磷酸化生成ATP的反应来抑制MCF-7细胞的增殖。本实验从代谢组学角度为乳腺癌抗肿瘤机制提供新的线索。
文摘为了考察水产品中二甲苯麝香和酮麝香的残留量，建立了水产品中痕量二甲苯麝香和酮麝香测定的多重吸附同步净化（MASP）-气相色谱-质谱联用法（GC-MS）。以乙腈高速匀浆提取样品，应用 MASP 方法对样品同时进行提取、盐析和净化，并采用 GC-MS 在选择离子监测（ SIM）模式下测定水产品中的痕量二甲苯麝香和酮麝香，以基质匹配标准溶液外标法定量。选用 DB-5 MS 石英毛细管柱（30 m×0.25 mm×0.25μm），采用电子轰击电离源，二甲苯麝香的选择监测离子为 m / z 282、297、265，酮麝香为 m / z 279、294、191。结果表明：在优化条件下，二甲苯麝香和酮麝香在1～100μg / kg 范围内线性良好，相关系数不低于0.999，检出限（S / N =3）为0.30μg / kg。明虾、花蛤和鳗鱼空白样品中1.0、2.0、10.0μg / kg 3个添加水平下二甲苯麝香和酮麝香的加标回收率为79％～104％，相对标准偏差（RSD）为1.6％～13.3％。本方法具有操作简便、快速、准确的特点，可用于水产品中痕量二甲苯麝香和酮麝香的日常检测。
文摘The chemical composition of essential oils obtained from Artemisia herba-alba and Mentha pulegium were determined. The essential oils were analyzed by gas chromatography coupled with mass spectrometry （GC/MS）. Their antibacterial activity was studied in vitro against three standard strains： E. coli ATCC 25922, Staphylococcus aureus ATCC 29213, Pseudomonas aeruginosa ATCC 27853, and five clinical strains： Enterobacter cloacae, Staphylococcus aureus, Pseudomonas pyocyanique, Enterococcus faecium, and E. coli. Nineteen constituents were identified in A. herba-alba essential oil representing 99.57% of the total composition The major component was α-thujone （59.07%）. The bacterial strains were inhibited at concentrations ranging from 1.25 μL/mL to 5μL/mL and killed at concentrations ranging from 1.25 μL/mL to 10 μL/mL. M. pulegium resulted in the identification of eighteen constituents representing 99.48% of the total composition. The main component was pulegone （78.07%）. The minimal inhibitory （MIC） and bactericidal （MBC） concentrations were ranging from 1.25 μL/mL to 2.5 μL/mL.
