This study explores the potential existence of local stocks of Synechogobius ommaturus using otolith chemical signatures. The concentrations of 10 elements （K, Ca, Na, Mg, St, Pb, Ba, Mn, Co, Zn） in the otoliths fro...This study explores the potential existence of local stocks of Synechogobius ommaturus using otolith chemical signatures. The concentrations of 10 elements （K, Ca, Na, Mg, St, Pb, Ba, Mn, Co, Zn） in the otoliths from eight stocks （Dandong, Dalian, Tianjin, Dongying, Weihai, Qingdao, Ganyu and Xiamen） ofS. ommaturus were measured by Inductively Coupled Plasma Mass Spectrometry and regressed against otolith weight. No significant correlation between otolith weight and concentrations of Na, Mg, Ca, Sr, Co, Ba, Zn and Pb were observed. Concentrations of K and Mn were correlated with otolith weight. Consequently, the residuals of the regressions were used instead of the original concentrations in subsequent analyses. Analysis of variance （ANOVA） showed no significant difference between males and females in otolith chemical signatures. Differences were found among the locations for K, Sr, Mn, Co, Ba, Pb, but not for Ca, Na, Mg and Zn. Residuals of the regressions of elemental concentrations against otolith weight that fitted the normal distribution and homogeneity were studied by discriminant analysis. The success of the discriminant function to predict the location of S. ommaturus capture ranged from 100% for Weihai and Xiamen stocks, to only 44.4% and 62.5% for Qingdao and Dandong stocks, respectively. The average prediction success was 80.3%.展开更多
An inductively coupled plasma mass spectrometry(ICP-MS) method was developed for the determination of Na, Mg, Al,K, Ca, Ti, Cr, Co, Ni, Cu, Ga, As, Mo, Ag, Cd and Pb in MnZn ferrites. The sample was digested by HNO3+H...An inductively coupled plasma mass spectrometry(ICP-MS) method was developed for the determination of Na, Mg, Al,K, Ca, Ti, Cr, Co, Ni, Cu, Ga, As, Mo, Ag, Cd and Pb in MnZn ferrites. The sample was digested by HNO3+HCl with microwave digestion followed by dilution with ultrapure water, then the above 16 impurity elements in the solution were analyzed directly by ICP-MS. The impurity elements were introduced by the helium gas or hydrogen gas into the octopole reaction system(ORS) to eliminate the polyatomic interferences caused by the high salty matrixes. The matrix effect was minimized through matrix matching,and Be, Y and Rh were used as internal standard elements. The working parameters of the instrument were optimized. The results show that the method has good precision and high accuracy. The detection limits for the investigated elements are in the range of0.9-37.5 ng/L, the relative standard deviation of each element is within 1.1%-4.8%, and the recovery of each element is 90%-108%.展开更多
The objective of the study was to research the aroma profile of volatile compounds in garlic subspecies originating from Latvia, and compare them with the aroma composition of garlic grown in the region of Midi-Pyrene...The objective of the study was to research the aroma profile of volatile compounds in garlic subspecies originating from Latvia, and compare them with the aroma composition of garlic grown in the region of Midi-Pyrenees （France）. It was established that hard-neck garlic tends to contain more diallyl disulfide （DADS）, the main decomposition product of allicin. Compared to the hard-neck subspecies, the content of allyl mercaptan, one of the major compounds producing the strong odor detectable after ingestion of garlic, was significantly lower in the soft-neck garlic clones. The amount of cyclic compound 3-vinyl-1,2-dithiin differed considerably with higher contents in the soft-neck subspecies. The results also demonstrate the soft-neck garlic as a more suitable subspecies for long-term storage. In general, the results show no significant difference in the content of DADS and the total content of other flavor compounds between hard-neck and soft-neck garlic grown in the region of Midi-Pyrenees and Latvia. However, comparing garlic subspecies originating from France and Latvia by the content of allyl mercaptan, 1,2-dithiolane and 3-vinyl-1,2-dithiin, a considerable proportional difference of these volatiles was determined. Also, a significant difference was established in the content of DADS between the white garlic variety ＂Blanc de Lomagne＂ （France, region of Midi-Pyrenees） and white garlic grown in other countries. The results of this study suggest the suitability of solid phase microextraction （SPME） and gas chromatography （GC） methods for quality control of garlic originating from France.展开更多
Lead(Pb)isotopes have been extensively employed in tracing sources of Pb and its transport pathways through the environment.However,Pb isotopic ratios in related geochemical reference materials are scarce.Here,we repo...Lead(Pb)isotopes have been extensively employed in tracing sources of Pb and its transport pathways through the environment.However,Pb isotopic ratios in related geochemical reference materials are scarce.Here,we report high-precision Pb isotopic ratios measured by Nu Plasma II MC-ICP-MS using calibrated ^(205)Tl/^(203)Tl=2.38865(NIST SRM 997)for mass discrimination correction.The long-term external precision(2SD)for NISTSRM 981 of Pb,BCR-2,and BHVO-2 are 0.31‰(n=105),0.42‰(n=11),and 0.25‰(n=5)for ^(208)Pb/ ^(206)Pb and 0.16‰,0.53‰,and 0.07‰for ^(206)Pb/ ^(207)Pb,both respectively,and their Pb isotopic ratios are in excellent agreement with the recommended values.Using this method,we report for the first time Pb isotopic compositions in shale SGR-1b(USGS);coal CLB-1(USGS);stream sediments GSD-17,-21,and-23(IGGE);soils GSS-12,-13,-14,-15,and-16(IGGE);plants GSV-1,-2,and-3(IGGE);and human hair GSH-1(IGGE).展开更多
Artemisinin is a potent anti-malarial drug isolated from traditional Chinese medicinal herb, Artemisia annua. The objective of this study was to develop and validate a sensitive and specific LC-MS/MS method for the de...Artemisinin is a potent anti-malarial drug isolated from traditional Chinese medicinal herb, Artemisia annua. The objective of this study was to develop and validate a sensitive and specific LC-MS/MS method for the determination of artemisinin in rat plasma using amlodipine as Internal Standard. The method consist of a simple liquid-liquid extraction with methyl tertiary butyl ether （MTBE） with subsequent evaporation of the supernatant to dryness followed by the analysis of the reconstituted sample by LC-MS/？vIS with a Z-spray atmospheric pressure ionization （API） interface in the positive ion-multiple reaction monitoring mode to monitor precursor--〉product ions of m/z 282.70--〉m/z 209.0 for artemisinin and m/z 408.9--〉m/z 237.0 for amlodipine respectively. The method was linear （0.999） over the concentration range of 7.8-2000 ng/mL in rat plasma. The intra and inter-day accuracy were measured to be within 94-104.2% and precision （CV） were all less than 5%. The extraction recovery means for internal standard and all the artemisinin concentrations used were between 82-85%.展开更多
基金Supported by the National Basic Research Program of China (973 program) (No. 2005CB422306)the Natural Science Foundation of Shandong Province (No. Y2008D21)+1 种基金the National Natural Science Foundation of China for Creative Research Groups (No. 40821004)the Open Fund of Key Laboratory of Marine and Estuarine Fisheries Resources and Ecology, Ministry of Agriculture
文摘This study explores the potential existence of local stocks of Synechogobius ommaturus using otolith chemical signatures. The concentrations of 10 elements （K, Ca, Na, Mg, St, Pb, Ba, Mn, Co, Zn） in the otoliths from eight stocks （Dandong, Dalian, Tianjin, Dongying, Weihai, Qingdao, Ganyu and Xiamen） ofS. ommaturus were measured by Inductively Coupled Plasma Mass Spectrometry and regressed against otolith weight. No significant correlation between otolith weight and concentrations of Na, Mg, Ca, Sr, Co, Ba, Zn and Pb were observed. Concentrations of K and Mn were correlated with otolith weight. Consequently, the residuals of the regressions were used instead of the original concentrations in subsequent analyses. Analysis of variance （ANOVA） showed no significant difference between males and females in otolith chemical signatures. Differences were found among the locations for K, Sr, Mn, Co, Ba, Pb, but not for Ca, Na, Mg and Zn. Residuals of the regressions of elemental concentrations against otolith weight that fitted the normal distribution and homogeneity were studied by discriminant analysis. The success of the discriminant function to predict the location of S. ommaturus capture ranged from 100% for Weihai and Xiamen stocks, to only 44.4% and 62.5% for Qingdao and Dandong stocks, respectively. The average prediction success was 80.3%.
基金Project(21271187)supported by the National Natural Science Foundation of ChinaProject(cstc2013jcyj A10088)supported by the Chongqing Natural Science Foundation,China+1 种基金Projects(2013FJ3093,2013SK3268)supported by the Science and Technology Project of Hunan Province,ChinaProject(KJZH14217)supported by Achievement Transfer Education in Chongqing,China
文摘An inductively coupled plasma mass spectrometry(ICP-MS) method was developed for the determination of Na, Mg, Al,K, Ca, Ti, Cr, Co, Ni, Cu, Ga, As, Mo, Ag, Cd and Pb in MnZn ferrites. The sample was digested by HNO3+HCl with microwave digestion followed by dilution with ultrapure water, then the above 16 impurity elements in the solution were analyzed directly by ICP-MS. The impurity elements were introduced by the helium gas or hydrogen gas into the octopole reaction system(ORS) to eliminate the polyatomic interferences caused by the high salty matrixes. The matrix effect was minimized through matrix matching,and Be, Y and Rh were used as internal standard elements. The working parameters of the instrument were optimized. The results show that the method has good precision and high accuracy. The detection limits for the investigated elements are in the range of0.9-37.5 ng/L, the relative standard deviation of each element is within 1.1%-4.8%, and the recovery of each element is 90%-108%.
文摘The objective of the study was to research the aroma profile of volatile compounds in garlic subspecies originating from Latvia, and compare them with the aroma composition of garlic grown in the region of Midi-Pyrenees （France）. It was established that hard-neck garlic tends to contain more diallyl disulfide （DADS）, the main decomposition product of allicin. Compared to the hard-neck subspecies, the content of allyl mercaptan, one of the major compounds producing the strong odor detectable after ingestion of garlic, was significantly lower in the soft-neck garlic clones. The amount of cyclic compound 3-vinyl-1,2-dithiin differed considerably with higher contents in the soft-neck subspecies. The results also demonstrate the soft-neck garlic as a more suitable subspecies for long-term storage. In general, the results show no significant difference in the content of DADS and the total content of other flavor compounds between hard-neck and soft-neck garlic grown in the region of Midi-Pyrenees and Latvia. However, comparing garlic subspecies originating from France and Latvia by the content of allyl mercaptan, 1,2-dithiolane and 3-vinyl-1,2-dithiin, a considerable proportional difference of these volatiles was determined. Also, a significant difference was established in the content of DADS between the white garlic variety ＂Blanc de Lomagne＂ （France, region of Midi-Pyrenees） and white garlic grown in other countries. The results of this study suggest the suitability of solid phase microextraction （SPME） and gas chromatography （GC） methods for quality control of garlic originating from France.
基金supported by National Key Basic Research Program of China(2014CB238903)the National Natural Science Foundation of China(Nos.41473028,41673017,U1612441)the Opening Fund of State Key Laboratory of Environmental Geochemistry(SKLEG2015201)
文摘Lead(Pb)isotopes have been extensively employed in tracing sources of Pb and its transport pathways through the environment.However,Pb isotopic ratios in related geochemical reference materials are scarce.Here,we report high-precision Pb isotopic ratios measured by Nu Plasma II MC-ICP-MS using calibrated ^(205)Tl/^(203)Tl=2.38865(NIST SRM 997)for mass discrimination correction.The long-term external precision(2SD)for NISTSRM 981 of Pb,BCR-2,and BHVO-2 are 0.31‰(n=105),0.42‰(n=11),and 0.25‰(n=5)for ^(208)Pb/ ^(206)Pb and 0.16‰,0.53‰,and 0.07‰for ^(206)Pb/ ^(207)Pb,both respectively,and their Pb isotopic ratios are in excellent agreement with the recommended values.Using this method,we report for the first time Pb isotopic compositions in shale SGR-1b(USGS);coal CLB-1(USGS);stream sediments GSD-17,-21,and-23(IGGE);soils GSS-12,-13,-14,-15,and-16(IGGE);plants GSV-1,-2,and-3(IGGE);and human hair GSH-1(IGGE).
文摘Artemisinin is a potent anti-malarial drug isolated from traditional Chinese medicinal herb, Artemisia annua. The objective of this study was to develop and validate a sensitive and specific LC-MS/MS method for the determination of artemisinin in rat plasma using amlodipine as Internal Standard. The method consist of a simple liquid-liquid extraction with methyl tertiary butyl ether （MTBE） with subsequent evaporation of the supernatant to dryness followed by the analysis of the reconstituted sample by LC-MS/？vIS with a Z-spray atmospheric pressure ionization （API） interface in the positive ion-multiple reaction monitoring mode to monitor precursor--〉product ions of m/z 282.70--〉m/z 209.0 for artemisinin and m/z 408.9--〉m/z 237.0 for amlodipine respectively. The method was linear （0.999） over the concentration range of 7.8-2000 ng/mL in rat plasma. The intra and inter-day accuracy were measured to be within 94-104.2% and precision （CV） were all less than 5%. The extraction recovery means for internal standard and all the artemisinin concentrations used were between 82-85%.
