[Objective]The aim was to identify the composition of pigments from Jujube fruit skin.[Method]Pigments were extracted from＇Lubei Dongzao＇,＇Lajiao Zao＇,＇Chengwu Dongzao＇,＇Dabailing＇and identificated by using hi...[Objective]The aim was to identify the composition of pigments from Jujube fruit skin.[Method]Pigments were extracted from＇Lubei Dongzao＇,＇Lajiao Zao＇,＇Chengwu Dongzao＇,＇Dabailing＇and identificated by using high performance liquid chromatography-mass spectrometry（HPLC-MS）.[Result]The results showed that eight flavanols and four to five flavonols were detected,no anthocyanins was detected.The contents of flavonoids were differnt in four varieties.The contents of flavanols（11 mg/g） and flavonols（1.78 mg/g） in＇Dabailing＇ were one-time higher than other varieties.Quercetin 3 rutinoside was the major flavonol.[Conclusion]The research provided theoretical basis for further study on mechanism of Jujube pigment turnning into the red.展开更多
[Objective] This study aimed to develop a method of C_18-functionalized magnetic silica nanoparticles solid phase extraction-high performance liquid chro- matography-tandem mass spectrometry for the determination of s...[Objective] This study aimed to develop a method of C_18-functionalized magnetic silica nanoparticles solid phase extraction-high performance liquid chro- matography-tandem mass spectrometry for the determination of sulfadimidine in royal jelly. [Method] The royal jelly samples were pretreated by MCX SPE column and C_18-functionalized magnetic silica nanoparticles, and the purified samples were de- tected by HPLC-MS/MS. [Result] The detection method showed a good linear rela- tionship in the range of 5-80 ugkg （r=0.993 1）. The recovery ranges were between 93%- 104% with the relative standard deviations （RSD） below 11.3%. [Conclusion] Combined with automation equipment, the method is simple, fast, time-saving, and easy to real- ize the automation of sulfadimidine in the royal jelly samples before determination.展开更多
Pectenotoxins (PTXs) are a group of marine algal toxins. In this study, the accumulation and depuration of pectenotoxins in brown crab Cancer pagurus were investigated. Crabs were fed with toxic blue mussels Mytilus e...Pectenotoxins (PTXs) are a group of marine algal toxins. In this study, the accumulation and depuration of pectenotoxins in brown crab Cancer pagurus were investigated. Crabs were fed with toxic blue mussels Mytilus edulis for 21 days and then depurated for 42 days. Toxins were extracted with methanol from the digestive glands of contaminated crabs, uncontaminated crabs (control group) and from blue mussels for comparison. Extracts were analyzed by liquid chromatograph coupled with tandem mass spectrometry (LC-MS-MS). The concentrations of PTX-2, PTX-2 SA, 7-epi-PTX-2 SA, and PTX-12 were analyzed in two batches of toxic blue mussels and the crabs. A one-compartment model was applied to describe the depuration of PTXs. The half-life of PTXs was estimated to be 6–7.5 days. After depuration for 42 days, the amount of PTXs measured in the crab digestive glands was less than 1 μg/kg.展开更多
The composition of fatty acids in triacylglycerides （TAGs） and their position on the glycerol backbone de- termine the nutritional value of vegetable oil. In this study, gas chromatography and high-performance liqui...The composition of fatty acids in triacylglycerides （TAGs） and their position on the glycerol backbone de- termine the nutritional value of vegetable oil. In this study, gas chromatography and high-performance liquid chromatography-tandem mass spectrometry （HPLC-MS/MS） were used to analyze the compo- sition and distribution of fatty acids in TAGs of different rapeseed oils. Our results show the content of oleic acid in higb-oleic-acid rapeseed oil to be about 80%. In terms of the number of acyl carbon atoms （CN）, TAGs with CN52-54 were most abundant, with a maximum concentration at CN54 （80%）. The main type of TAG was oleic-oleic-oleic （OOO）, accounting for 71.75%, while oleic-oleic-linoleic （OOL） accounted for ？.56%, oleic-oleic-linolenic （OOLn） accounted for 4.81%, and stearic-oleic-oleic （SO0） accounted for 4.74%. Oleic acid in high-oleic-acid rapeseed oil was distributed in the following order of preference： sn-2 〉 sn-1/3. In high-erucic-acid rapeseed oil, however, oleic acid was enriched at the sn-1/3. These data show that the content of oleic acid can be as high as about 80% in high-oleic-acid material. This finding suggests that high-oleic-acid rapeseed oil has high nutritional value.展开更多
Matrix effects can significantly hamper the accuracy and precision of the analysis results of perfluorinated acids （PFAs） in environmental solid samples. Several methods, such as standard addition, isotopically labe...Matrix effects can significantly hamper the accuracy and precision of the analysis results of perfluorinated acids （PFAs） in environmental solid samples. Several methods, such as standard addition, isotopically labeled internal standards, clean-up of SPE （solid phase extraction） eluents by dispersive graphitized carbon sorbent and substitution of eletrospray ionization （ESI） source by atmosphere pressure photoionization （APPI） source, were demonstrated for elimination of matrix effects in quantitative analysis of PFAs in solid samples. The resuRs indicate that matrix effects can be effectively eliminated by standard addition, but instrumental analysis time will be multiplied. Isotopically labeled internal standards can effectively negate matrix effects of PFAs with the same perfluorocarbon chain length, but is not valid for the other analytes. Although APPI can eliminate matrix effects for all analytes, it is only suitable for analysis of high pollution levels samples. Clean-up of SPE eluents by dispersive graphitized carbon sorbent not only effectively negate the impact of matrix effect, but also avoid frequent clean of the ESI in order to maintain instrumental sensitivity. Therefore, the best method for elimination of matrix effects is the usage of dispersive graphitized carbon sorbent for clean-up of SPE elution.展开更多
[Objective] A quick extraction method of QuEChERS-HPLC-MS/MS was established to determine forechlorfenuron in fruits and vegetables. [Method] Fruits and vegetables were extracted with 0.1% acetic acid of acetonitrile ...[Objective] A quick extraction method of QuEChERS-HPLC-MS/MS was established to determine forechlorfenuron in fruits and vegetables. [Method] Fruits and vegetables were extracted with 0.1% acetic acid of acetonitrile solution and pu- rified by QuEChERS, and then forechlorfenuron residues were determined by HPLC- MS/MS. [Result] The limits of detection （LODs） and low determination limit （LOQ） for the forechlorfenuron was 1.0 vg/kg and 5.0 pg/kg in fruits and vegetables, re- spectively. Regression equations of these hormones had a good linear relationship （FF〉0.999） within 2.0-100.0 vg/L. The average recoveries of forechlorfenuron was in the range of 72.0-115. 0% with the coefficients of variation between 1.5% and 9.8% at the spiked levels of 10.0-500.0 μg/kg. [Conclusion] The method can be applied for the determination of the forechlorfenuron in fruits and vegetables.展开更多
Among pharmaceuticals and personal care products released into the aquatic environment, antibiotics are of particular concern, because of their ubiquity and health effects. Although scientists have recently paid more ...Among pharmaceuticals and personal care products released into the aquatic environment, antibiotics are of particular concern, because of their ubiquity and health effects. Although scientists have recently paid more attention to the threat of antibiotics to coastal ecosystems, researchers have often focused on relatively few antibiotics, because of the absence of suitable analytical methods. We have therefore developed a method for the rapid detection of 36 antibiotic residues in coastal waters, including tetracyclines （TCs）, sulfanilamides （SAs）, and quinolones （QLs）. The method consists of solid-phase extraction （SPE） and liquid chromatography-tandem mass spectrometry （LC-MS/MS） analysis, using electrospray ionization （ESI） in positive mode. The SPE was performed with Oasis HLB and Oasis MCX cartridges. Chromatographic separation on a Cr8 column was achieved using a binary eluent containing methanol and water with 0.1% formic acid. Typical recoveries of the analytes ranged from 67.4% to 109.3% at a fortification level of 100 ng/L. The precision of the method, calculated as relative standard deviation （RSD）, was below 14.6% for all the compounds. The limits of detection （LODs） varied from 0.45 pg to 7.97 pg. The method was applied to detemaine the target analytes in coastal waters of the Yellow Sea in Liaoning, China. Among the tested antibiotics, 31 were found in coastal ＇waters, with their concentrations between the LOD and 212.5 ng/L. These data indicate that this method is valid for analysis of antibiotics in coastal waters. The study first reports such a large number of antibiotics along the Yellow Sea coast of Liaoning, and should facilitate future comprehensive evaluation of antibiotics in coastal ecosystems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
A procedure based on the QuEChERS methodology and Liquid Chromatography Tandem Mass Spectrometry （LC/MS/MS） is described, for the determination of Nicotine in mushrooms. QuEChERS methodology was used to determine Ni...A procedure based on the QuEChERS methodology and Liquid Chromatography Tandem Mass Spectrometry （LC/MS/MS） is described, for the determination of Nicotine in mushrooms. QuEChERS methodology was used to determine Nicotine in dried and fresh mushrooms under basic conditions with primary secondary amino sorbent （PSA） clean up. The chromatography was performed on C 18 reversed phase column using a gradient of acetonitrile and ammonium formiate lmM pH = 3.4 as mobile phase at a flow rate of 0.3 mL min^-1. Nicotine was determined by using Nicotine-d3 as internal standard. Limit of quantification （LOQ） was 0.01 mg kg^-1 for both fresh and dried mushrooms. Calibration curve was linear over the concentration range of 0.01-2.3 mg mL^-1, with r2 〉 0.99. As for recoveries in dried mushrooms, spiking levels of 0.32 mg kg^-1 and 2 mg kg^-1 were considered whereas for the fresh mushrooms the recoveries were determined at 0.036 mg kg^-1 and 0.36 mg kg^-1. Satisfactory results were obtained for both matrices and the recoveries proved to range from 105% to 135%, with a standard deviation in the range 17-20. The method was applied to the analysis of Nicotine to assess the levels of nicotine in fresh and dried mushrooms.展开更多
A randomized, two-way, crossover study was conducted in 15 fasting, healthy, Algerian volunteers to compare the bioavailability of two brands of Valsartan 80 mg coated breakable tablets. The present study aimed to eva...A randomized, two-way, crossover study was conducted in 15 fasting, healthy, Algerian volunteers to compare the bioavailability of two brands of Valsartan 80 mg coated breakable tablets. The present study aimed to evaluate the intra-subject variability of this active substance in the Algerian population. The test brand was compared to TAREG （Novartis） as the reference product. The study was performed at the bioequivalence center of the national control laboratory for pharmaceuticals products, in joint venture with University Hospital Center Ibn Badis, Constantine, Algeria. The drug was administered with 200 mL of water after a 10 h overnight fasting on two treatment days separated by one week washout period. After dosing, serial blood samples were collected for a period of 24 h. A reliable, simple, and robust liquid chromatography-tandem mass spectro-metric （LC-MS/MS） method has been developed and validated that employs protein precipitation （or denaturation） for the estimation of valsartan in human plasma using losartan as internal standard. The assay was found to be linear over the range of 50-5,000 ng/mL, with a lower limit of quantitation of 50ng/mL. Various pharnaacokinetic parameters including AUC0-t, AUC∞, Cmax, Tmax, and TI/2 were determined from plasma concentrations of both formulations and found to be in good agreement with reported values. The pharmacokinetical and statistical analysis was conducted with Kinetica 4.4.1. AUC0.t, AUC0-∞ and Cmax were tested for bioequivalence after log-transformation of data. No significant difference was found based on ANOVA; 90% confidence interval （[85.82%, 118.76%] for AUC0.t [86.09%, 118.83%] for AUC0-∞） of test/reference ratio for these parameters were found within bioequivalence acceptance range of 80-125%. But for the Cmax, the 90% confidence interval of test/reference ratio wasn＇t in this acceptance range [90.18%, 131.07%] .The results of PK analysis suggested that the reference and test formulations ofvalsartan 80 mg coated breakable tablets weren＇t bioequivalent during fasting state in these healthy algerian volunteers.展开更多
A randomized, two-way, crossover study was conducted in 12 fasting, healthy, algerian volunteers to compare the bioavailability of two brands of metformin hydrochloride 850 mg coated tablets. The present study aimed t...A randomized, two-way, crossover study was conducted in 12 fasting, healthy, algerian volunteers to compare the bioavailability of two brands of metformin hydrochloride 850 mg coated tablets. The present study aimed to appreciate the bioequivalence of the generic product and to evaluate the intra-subject variability of this active substance in the Algerian population. The test brand was compared to Glucophage （Merck UK） as the reference product. The study was performed at the bioequivalence center of the national control laboratory for pharmaceuticals products from 03 to 04, 2011, in joint venture with specialized medical hospital center of E1 Hadi Flici, Algiers, Algeria. The drug was administered with 200 mL of water after a 10 h overnight fasting on two treatment days separated by one week washout period. After dosing, serial blood samples were collected for a period of 12 h. A reliable, simple, and robust liquid chromatography-tandem mass spectro-metric （LC-MS/MS） method has been developed and validated for estimation of metformin in human plasma using propranolol as internal standard. The analytes were extracted from plasma by using the protein precipitation extraction technique. The assay was found to be linear over the range of 50-3000 ng/mL with a lower limit of quantitation of 50 ng/mL. Various pharmacokinetic parameters including AUC0-t, AUC0-∞, Cmax, Tmax, and T1/2 were determined from plasma concentrations of both formulations and found to be in good agreement with reported values. The pharmacokinetical and statistical analysis was conducted with Kinetica 4.4.1. AUC0-t, AUC0-∞ and Cmax were tested for bioequivalence after log-transformation of data. No significant difference was found based on ANOVA; 90% confidence interval （[91.62 %, 115.66%] for AUC0-t, [92.07 %, 115.53 %] for AUC0-∞; [94.58%, 119.58 %] for Cmax） of test/reference ratio for these parameters were found within bioequivalence acceptance range of 80-125%. Based on these statistical inferences, it was concluded that Metformin hydrochloride test is bioequivalent to Glucophage.展开更多
We investigated the metabolism of pectenotoxins in brown crabs(Cancer pagurus).The crabs were fed with blue mussels(Mytilus edulis) for 21 d then depurated for 42 d.We extracted the toxins from the digestive glands of...We investigated the metabolism of pectenotoxins in brown crabs(Cancer pagurus).The crabs were fed with blue mussels(Mytilus edulis) for 21 d then depurated for 42 d.We extracted the toxins from the digestive glands of contaminated crabs,uncontaminated crabs(control group),and the meat of blue mussels using methanol.Extracts of the crab digestive glands were fractionated by liquid-liquid partitioning and solid phase extraction.The fractions were analyzed by liquid chromatography coupled with tandem mass spectrometry(LC-MS/MS) and liquid chromatography coupled with ion-trap mass spectrometry(LC-MSn).We detected a new PTX-like compound,designated as metabolite-1.The MS2 mass spectrum of the metabolite-1 [M+Na]+ ion at m/z 897.5 revealed fragment ions at m/z 853.5 and 555.5,typical of those exhibited by other pectenotoxins.展开更多
Polyphenols were obtained from the natural dried Lonicerae flos by ultrasound-assisted extraction with ethanol as the solvent.Single factor experiment and response surface methodology were employed to optimize the ext...Polyphenols were obtained from the natural dried Lonicerae flos by ultrasound-assisted extraction with ethanol as the solvent.Single factor experiment and response surface methodology were employed to optimize the extraction conditions.Ultra-performance liquid chromatrography(UPLC)-tandem mass spectrometry(MS/MS)was employed to identify polyphenols based on the plant widely targeted metabolomics database in a qualitative and quantitative manner.The results showed that the optimal extraction conditions for total phenols from Lonicerae flos were ultrasound-assisted extraction with a solid-to-liquid ratio of 10∶1 g/mL and 57%ethanol at 70 W and 60°C for 11 min.The yield of total phenols extracted under the optimal conditions reached 71.08 mg/g.The phenols in Lonicerae flos were mainly chlorogenic acid isomers,and the flavonoids were mainly nobiletin,galuteolin,and homoarbutin.展开更多
基金Supported by National Key Technology R & D Program 2006BAD01A1701 and 2006BAD18B02Shandong Agriculture Good Cultivar Engineering Project (2008LZ09)~~
文摘[Objective]The aim was to identify the composition of pigments from Jujube fruit skin.[Method]Pigments were extracted from＇Lubei Dongzao＇,＇Lajiao Zao＇,＇Chengwu Dongzao＇,＇Dabailing＇and identificated by using high performance liquid chromatography-mass spectrometry（HPLC-MS）.[Result]The results showed that eight flavanols and four to five flavonols were detected,no anthocyanins was detected.The contents of flavonoids were differnt in four varieties.The contents of flavanols（11 mg/g） and flavonols（1.78 mg/g） in＇Dabailing＇ were one-time higher than other varieties.Quercetin 3 rutinoside was the major flavonol.[Conclusion]The research provided theoretical basis for further study on mechanism of Jujube pigment turnning into the red.
基金Supported by the Innovation Fund for Technology Based Firms of Ministry of Science and Technology(09C26214425280)the National Key Technology R&D Program during the 12th Five-Year Plan Period(2012BAK17B10)the International S&T Cooperation and Communication Program of China(2011DFA32930)~~
文摘[Objective] This study aimed to develop a method of C_18-functionalized magnetic silica nanoparticles solid phase extraction-high performance liquid chro- matography-tandem mass spectrometry for the determination of sulfadimidine in royal jelly. [Method] The royal jelly samples were pretreated by MCX SPE column and C_18-functionalized magnetic silica nanoparticles, and the purified samples were de- tected by HPLC-MS/MS. [Result] The detection method showed a good linear rela- tionship in the range of 5-80 ugkg （r=0.993 1）. The recovery ranges were between 93%- 104% with the relative standard deviations （RSD） below 11.3%. [Conclusion] Combined with automation equipment, the method is simple, fast, time-saving, and easy to real- ize the automation of sulfadimidine in the royal jelly samples before determination.
基金Supported by Norwegian Education Funding "Quata"(2005)
文摘Pectenotoxins (PTXs) are a group of marine algal toxins. In this study, the accumulation and depuration of pectenotoxins in brown crab Cancer pagurus were investigated. Crabs were fed with toxic blue mussels Mytilus edulis for 21 days and then depurated for 42 days. Toxins were extracted with methanol from the digestive glands of contaminated crabs, uncontaminated crabs (control group) and from blue mussels for comparison. Extracts were analyzed by liquid chromatograph coupled with tandem mass spectrometry (LC-MS-MS). The concentrations of PTX-2, PTX-2 SA, 7-epi-PTX-2 SA, and PTX-12 were analyzed in two batches of toxic blue mussels and the crabs. A one-compartment model was applied to describe the depuration of PTXs. The half-life of PTXs was estimated to be 6–7.5 days. After depuration for 42 days, the amount of PTXs measured in the crab digestive glands was less than 1 μg/kg.
文摘The composition of fatty acids in triacylglycerides （TAGs） and their position on the glycerol backbone de- termine the nutritional value of vegetable oil. In this study, gas chromatography and high-performance liquid chromatography-tandem mass spectrometry （HPLC-MS/MS） were used to analyze the compo- sition and distribution of fatty acids in TAGs of different rapeseed oils. Our results show the content of oleic acid in higb-oleic-acid rapeseed oil to be about 80%. In terms of the number of acyl carbon atoms （CN）, TAGs with CN52-54 were most abundant, with a maximum concentration at CN54 （80%）. The main type of TAG was oleic-oleic-oleic （OOO）, accounting for 71.75%, while oleic-oleic-linoleic （OOL） accounted for ？.56%, oleic-oleic-linolenic （OOLn） accounted for 4.81%, and stearic-oleic-oleic （SO0） accounted for 4.74%. Oleic acid in high-oleic-acid rapeseed oil was distributed in the following order of preference： sn-2 〉 sn-1/3. In high-erucic-acid rapeseed oil, however, oleic acid was enriched at the sn-1/3. These data show that the content of oleic acid can be as high as about 80% in high-oleic-acid material. This finding suggests that high-oleic-acid rapeseed oil has high nutritional value.
基金Foundation item: Projects(51108197, 51205215) supported by the National Natural Science Foundation of ChinaProjects(2011J05135, 2011J01318) supported by the Natural Science Foundation of Fujian Province, China+1 种基金Project(11QZR08) supported by the Scientific Research Foundation of Overseas Chinese Affairs Office of the State Council,ChinaProject(10BS213) supported by the Scientific Research Foundation for Advanced Talents,Huaqiao University,China
文摘Matrix effects can significantly hamper the accuracy and precision of the analysis results of perfluorinated acids （PFAs） in environmental solid samples. Several methods, such as standard addition, isotopically labeled internal standards, clean-up of SPE （solid phase extraction） eluents by dispersive graphitized carbon sorbent and substitution of eletrospray ionization （ESI） source by atmosphere pressure photoionization （APPI） source, were demonstrated for elimination of matrix effects in quantitative analysis of PFAs in solid samples. The resuRs indicate that matrix effects can be effectively eliminated by standard addition, but instrumental analysis time will be multiplied. Isotopically labeled internal standards can effectively negate matrix effects of PFAs with the same perfluorocarbon chain length, but is not valid for the other analytes. Although APPI can eliminate matrix effects for all analytes, it is only suitable for analysis of high pollution levels samples. Clean-up of SPE eluents by dispersive graphitized carbon sorbent not only effectively negate the impact of matrix effect, but also avoid frequent clean of the ESI in order to maintain instrumental sensitivity. Therefore, the best method for elimination of matrix effects is the usage of dispersive graphitized carbon sorbent for clean-up of SPE elution.
文摘[Objective] A quick extraction method of QuEChERS-HPLC-MS/MS was established to determine forechlorfenuron in fruits and vegetables. [Method] Fruits and vegetables were extracted with 0.1% acetic acid of acetonitrile solution and pu- rified by QuEChERS, and then forechlorfenuron residues were determined by HPLC- MS/MS. [Result] The limits of detection （LODs） and low determination limit （LOQ） for the forechlorfenuron was 1.0 vg/kg and 5.0 pg/kg in fruits and vegetables, re- spectively. Regression equations of these hormones had a good linear relationship （FF〉0.999） within 2.0-100.0 vg/L. The average recoveries of forechlorfenuron was in the range of 72.0-115. 0% with the coefficients of variation between 1.5% and 9.8% at the spiked levels of 10.0-500.0 μg/kg. [Conclusion] The method can be applied for the determination of the forechlorfenuron in fruits and vegetables.
基金Supported by Young Scientists Research Program (No. 2009507)the Key Laboratory of Marine Bioactive Substances and Modern Analytical Techniques (No. MBSMAT-2010-04),SOA of China
文摘Among pharmaceuticals and personal care products released into the aquatic environment, antibiotics are of particular concern, because of their ubiquity and health effects. Although scientists have recently paid more attention to the threat of antibiotics to coastal ecosystems, researchers have often focused on relatively few antibiotics, because of the absence of suitable analytical methods. We have therefore developed a method for the rapid detection of 36 antibiotic residues in coastal waters, including tetracyclines （TCs）, sulfanilamides （SAs）, and quinolones （QLs）. The method consists of solid-phase extraction （SPE） and liquid chromatography-tandem mass spectrometry （LC-MS/MS） analysis, using electrospray ionization （ESI） in positive mode. The SPE was performed with Oasis HLB and Oasis MCX cartridges. Chromatographic separation on a Cr8 column was achieved using a binary eluent containing methanol and water with 0.1% formic acid. Typical recoveries of the analytes ranged from 67.4% to 109.3% at a fortification level of 100 ng/L. The precision of the method, calculated as relative standard deviation （RSD）, was below 14.6% for all the compounds. The limits of detection （LODs） varied from 0.45 pg to 7.97 pg. The method was applied to detemaine the target analytes in coastal waters of the Yellow Sea in Liaoning, China. Among the tested antibiotics, 31 were found in coastal ＇waters, with their concentrations between the LOD and 212.5 ng/L. These data indicate that this method is valid for analysis of antibiotics in coastal waters. The study first reports such a large number of antibiotics along the Yellow Sea coast of Liaoning, and should facilitate future comprehensive evaluation of antibiotics in coastal ecosystems
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%.
文摘A procedure based on the QuEChERS methodology and Liquid Chromatography Tandem Mass Spectrometry （LC/MS/MS） is described, for the determination of Nicotine in mushrooms. QuEChERS methodology was used to determine Nicotine in dried and fresh mushrooms under basic conditions with primary secondary amino sorbent （PSA） clean up. The chromatography was performed on C 18 reversed phase column using a gradient of acetonitrile and ammonium formiate lmM pH = 3.4 as mobile phase at a flow rate of 0.3 mL min^-1. Nicotine was determined by using Nicotine-d3 as internal standard. Limit of quantification （LOQ） was 0.01 mg kg^-1 for both fresh and dried mushrooms. Calibration curve was linear over the concentration range of 0.01-2.3 mg mL^-1, with r2 〉 0.99. As for recoveries in dried mushrooms, spiking levels of 0.32 mg kg^-1 and 2 mg kg^-1 were considered whereas for the fresh mushrooms the recoveries were determined at 0.036 mg kg^-1 and 0.36 mg kg^-1. Satisfactory results were obtained for both matrices and the recoveries proved to range from 105% to 135%, with a standard deviation in the range 17-20. The method was applied to the analysis of Nicotine to assess the levels of nicotine in fresh and dried mushrooms.
文摘A randomized, two-way, crossover study was conducted in 15 fasting, healthy, Algerian volunteers to compare the bioavailability of two brands of Valsartan 80 mg coated breakable tablets. The present study aimed to evaluate the intra-subject variability of this active substance in the Algerian population. The test brand was compared to TAREG （Novartis） as the reference product. The study was performed at the bioequivalence center of the national control laboratory for pharmaceuticals products, in joint venture with University Hospital Center Ibn Badis, Constantine, Algeria. The drug was administered with 200 mL of water after a 10 h overnight fasting on two treatment days separated by one week washout period. After dosing, serial blood samples were collected for a period of 24 h. A reliable, simple, and robust liquid chromatography-tandem mass spectro-metric （LC-MS/MS） method has been developed and validated that employs protein precipitation （or denaturation） for the estimation of valsartan in human plasma using losartan as internal standard. The assay was found to be linear over the range of 50-5,000 ng/mL, with a lower limit of quantitation of 50ng/mL. Various pharnaacokinetic parameters including AUC0-t, AUC∞, Cmax, Tmax, and TI/2 were determined from plasma concentrations of both formulations and found to be in good agreement with reported values. The pharmacokinetical and statistical analysis was conducted with Kinetica 4.4.1. AUC0.t, AUC0-∞ and Cmax were tested for bioequivalence after log-transformation of data. No significant difference was found based on ANOVA; 90% confidence interval （[85.82%, 118.76%] for AUC0.t [86.09%, 118.83%] for AUC0-∞） of test/reference ratio for these parameters were found within bioequivalence acceptance range of 80-125%. But for the Cmax, the 90% confidence interval of test/reference ratio wasn＇t in this acceptance range [90.18%, 131.07%] .The results of PK analysis suggested that the reference and test formulations ofvalsartan 80 mg coated breakable tablets weren＇t bioequivalent during fasting state in these healthy algerian volunteers.
文摘A randomized, two-way, crossover study was conducted in 12 fasting, healthy, algerian volunteers to compare the bioavailability of two brands of metformin hydrochloride 850 mg coated tablets. The present study aimed to appreciate the bioequivalence of the generic product and to evaluate the intra-subject variability of this active substance in the Algerian population. The test brand was compared to Glucophage （Merck UK） as the reference product. The study was performed at the bioequivalence center of the national control laboratory for pharmaceuticals products from 03 to 04, 2011, in joint venture with specialized medical hospital center of E1 Hadi Flici, Algiers, Algeria. The drug was administered with 200 mL of water after a 10 h overnight fasting on two treatment days separated by one week washout period. After dosing, serial blood samples were collected for a period of 12 h. A reliable, simple, and robust liquid chromatography-tandem mass spectro-metric （LC-MS/MS） method has been developed and validated for estimation of metformin in human plasma using propranolol as internal standard. The analytes were extracted from plasma by using the protein precipitation extraction technique. The assay was found to be linear over the range of 50-3000 ng/mL with a lower limit of quantitation of 50 ng/mL. Various pharmacokinetic parameters including AUC0-t, AUC0-∞, Cmax, Tmax, and T1/2 were determined from plasma concentrations of both formulations and found to be in good agreement with reported values. The pharmacokinetical and statistical analysis was conducted with Kinetica 4.4.1. AUC0-t, AUC0-∞ and Cmax were tested for bioequivalence after log-transformation of data. No significant difference was found based on ANOVA; 90% confidence interval （[91.62 %, 115.66%] for AUC0-t, [92.07 %, 115.53 %] for AUC0-∞; [94.58%, 119.58 %] for Cmax） of test/reference ratio for these parameters were found within bioequivalence acceptance range of 80-125%. Based on these statistical inferences, it was concluded that Metformin hydrochloride test is bioequivalent to Glucophage.
基金Supported by Norwegian International Education Funding,Quota Program
文摘We investigated the metabolism of pectenotoxins in brown crabs(Cancer pagurus).The crabs were fed with blue mussels(Mytilus edulis) for 21 d then depurated for 42 d.We extracted the toxins from the digestive glands of contaminated crabs,uncontaminated crabs(control group),and the meat of blue mussels using methanol.Extracts of the crab digestive glands were fractionated by liquid-liquid partitioning and solid phase extraction.The fractions were analyzed by liquid chromatography coupled with tandem mass spectrometry(LC-MS/MS) and liquid chromatography coupled with ion-trap mass spectrometry(LC-MSn).We detected a new PTX-like compound,designated as metabolite-1.The MS2 mass spectrum of the metabolite-1 [M+Na]+ ion at m/z 897.5 revealed fragment ions at m/z 853.5 and 555.5,typical of those exhibited by other pectenotoxins.
基金Supported by Agricultural Science and Technology Innovation Fund Project of Hunan Province(2022CX87)Huaihua Municipal Institute of Science and Technology Cooperation Project(2022N1203)Science and Technology Talent Lifting Project of Hunan Province—Training Plan for Young and Middle-aged Scholars(2023TJ-Z01)。
文摘Polyphenols were obtained from the natural dried Lonicerae flos by ultrasound-assisted extraction with ethanol as the solvent.Single factor experiment and response surface methodology were employed to optimize the extraction conditions.Ultra-performance liquid chromatrography(UPLC)-tandem mass spectrometry(MS/MS)was employed to identify polyphenols based on the plant widely targeted metabolomics database in a qualitative and quantitative manner.The results showed that the optimal extraction conditions for total phenols from Lonicerae flos were ultrasound-assisted extraction with a solid-to-liquid ratio of 10∶1 g/mL and 57%ethanol at 70 W and 60°C for 11 min.The yield of total phenols extracted under the optimal conditions reached 71.08 mg/g.The phenols in Lonicerae flos were mainly chlorogenic acid isomers,and the flavonoids were mainly nobiletin,galuteolin,and homoarbutin.
