The measurement of urine catecholamine and metanephrine concentrations is important for biochemical screening and diagnosis of pheochromocytoma.The goal of this work was to develop a simple liquid chromatography-tande...The measurement of urine catecholamine and metanephrine concentrations is important for biochemical screening and diagnosis of pheochromocytoma.The goal of this work was to develop a simple liquid chromatography-tandem mass spectrometry(LC-MS/MS)method for determining catecholamines and metanephrines in urine to replace an existing liquid chromatographic method using electrochemical detection.Urine samples were prepared using Oasis weak-cation-exchange cartridges.The eluate was analyzed on an Agilent ZORBAX Eclipse Plus Phenyl-Hexyl column in 3 min.Adrenaline,noradrenaline,dopamine,metanephrine,normetanephrine,and their deuterated internal standards were monitored in positive electrospray ionization mode by multiple reaction monitoring(MRM).No evidence of ion suppression was observed.The assay was linear up to 5μmol/L for adrenaline,5μmol/L for noradrenaline,6.1μmol/L for dopamine,5.6μmol/L for metanephrine,and 34.6μmol/L for normetanephrine,with lower limits of quantification of 5,5,12,6 and 7nmol/L,respectively.The intra-day and inter-day precisions for all analytes ranged from 0.59%to 4.64%and1.98%to 4.80%,respectively.External quality assurance samples were assayed and showed excellent agreement with the target values.This simple method provides an improved assay for determining urine catecholamines and metanephrines.展开更多
The major objective of this study was to determine the effect of corn straw or mixed diet on the small molecule metabolites of liver and milk production of healthy Chinese Holstein cows during lactation.In this study,...The major objective of this study was to determine the effect of corn straw or mixed diet on the small molecule metabolites of liver and milk production of healthy Chinese Holstein cows during lactation.In this study,metabolomic methods based on ultra performance liquid chromatography-mass spectrometry(LC-MS)were used to study the liver metabolites of dairy cows fed on corn straw diet or mixed diet.Ten healthy Chinese Holstein cows were randomly assigned to two groups,under the same management condition,fed different diets respectively,corn straw group(CS)or a mixture of alfalfa hay and Chinese wild rye hay mixed forage group(MF).All the cows were fed for 8 weeks and recorded body weight,dry matter intake,body condition score,fat,protein,lactose,milk yield and the total solids.Livers were sampled from each cow through a liver puncture needle for analysis of a significant difference in small molecule metabolites in cow liver samples from the two different diets.The results suggested that different diet types had significant effects on liver metabolism and milk components in dairy cows.The contents of milk fat,the total solids,milk protein,lactose,dry matter intake(DMI),milk yield,milk protein(%),lactose(%)and milk fat(%)of the corn straw group were significantly lower than those of the mixed forage group(p<0.05);the contents of phosphatidylcholine(PC),histidine,hypoxanthine and mridine in liver tissues of the corn straw group were significantly lower than those in the mixed forage group(p<0.05);acetylcarnitine,uric acid,triacylglycerol(TG),acetal phosphatidylcholine(plasmenyl-PC),acetalphosphatidylethanolamine(plasmenyl-PE)and sphingomyelin(SM)of the corn straw group were significantly higher than those in the mixed forage group(p<0.05).In summary,cows fed on mixed forage diet significantly improved milk yield and lactation performance clearly.展开更多
Surfactant is widely used in the industry,and its determination is important in both performance and quality control consideration.A liquid chromatography coupling mass spectrometry(LC-MS)method was established for an...Surfactant is widely used in the industry,and its determination is important in both performance and quality control consideration.A liquid chromatography coupling mass spectrometry(LC-MS)method was established for analyzing surfactants in lubricant.Three surfactants,including polyoxyethylene(9)nonyl phenyl ether,polyoxyethylene(10)decanamine ether,and polyoxyethylene(5)oleylamine ether were identified.展开更多
To establish HPLC electrospray ionization mass spectrometry (HPLC-ESI MS) method for determination of osthole in food additive.The samples were dipped in methanol overnight and extracted with it by ultrasonic instrume...To establish HPLC electrospray ionization mass spectrometry (HPLC-ESI MS) method for determination of osthole in food additive.The samples were dipped in methanol overnight and extracted with it by ultrasonic instrument,then the supernatant was send to sampler for detection.Sample was chromatographed using 0.4%HAc solution-MeOH (35:65,by volume) mobile phase on an Xterra MS C18 column.Analyte determination was performed by ESI MS/MS in the multiple reaction monitoring(MRM)mode.The established method of LC-MS/MS determining the concentration of osthole in food additive has the characteristic of strong specificity,high sensitivity and good reproducibility.The linear range of papaverine was 0.001-10 μg/mL,method recovery was 97.42%,RSD was 8.37%,the limit of detection was 1 ng/mL and the limit of quantitation was 0.001 μg/mL.展开更多
文摘The measurement of urine catecholamine and metanephrine concentrations is important for biochemical screening and diagnosis of pheochromocytoma.The goal of this work was to develop a simple liquid chromatography-tandem mass spectrometry(LC-MS/MS)method for determining catecholamines and metanephrines in urine to replace an existing liquid chromatographic method using electrochemical detection.Urine samples were prepared using Oasis weak-cation-exchange cartridges.The eluate was analyzed on an Agilent ZORBAX Eclipse Plus Phenyl-Hexyl column in 3 min.Adrenaline,noradrenaline,dopamine,metanephrine,normetanephrine,and their deuterated internal standards were monitored in positive electrospray ionization mode by multiple reaction monitoring(MRM).No evidence of ion suppression was observed.The assay was linear up to 5μmol/L for adrenaline,5μmol/L for noradrenaline,6.1μmol/L for dopamine,5.6μmol/L for metanephrine,and 34.6μmol/L for normetanephrine,with lower limits of quantification of 5,5,12,6 and 7nmol/L,respectively.The intra-day and inter-day precisions for all analytes ranged from 0.59%to 4.64%and1.98%to 4.80%,respectively.External quality assurance samples were assayed and showed excellent agreement with the target values.This simple method provides an improved assay for determining urine catecholamines and metanephrines.
基金Supported by the National Natural Science Foundation of China(31101784)Funds for Young Researchers from Northeast Agricultural University(14QC43)。
文摘The major objective of this study was to determine the effect of corn straw or mixed diet on the small molecule metabolites of liver and milk production of healthy Chinese Holstein cows during lactation.In this study,metabolomic methods based on ultra performance liquid chromatography-mass spectrometry(LC-MS)were used to study the liver metabolites of dairy cows fed on corn straw diet or mixed diet.Ten healthy Chinese Holstein cows were randomly assigned to two groups,under the same management condition,fed different diets respectively,corn straw group(CS)or a mixture of alfalfa hay and Chinese wild rye hay mixed forage group(MF).All the cows were fed for 8 weeks and recorded body weight,dry matter intake,body condition score,fat,protein,lactose,milk yield and the total solids.Livers were sampled from each cow through a liver puncture needle for analysis of a significant difference in small molecule metabolites in cow liver samples from the two different diets.The results suggested that different diet types had significant effects on liver metabolism and milk components in dairy cows.The contents of milk fat,the total solids,milk protein,lactose,dry matter intake(DMI),milk yield,milk protein(%),lactose(%)and milk fat(%)of the corn straw group were significantly lower than those of the mixed forage group(p<0.05);the contents of phosphatidylcholine(PC),histidine,hypoxanthine and mridine in liver tissues of the corn straw group were significantly lower than those in the mixed forage group(p<0.05);acetylcarnitine,uric acid,triacylglycerol(TG),acetal phosphatidylcholine(plasmenyl-PC),acetalphosphatidylethanolamine(plasmenyl-PE)and sphingomyelin(SM)of the corn straw group were significantly higher than those in the mixed forage group(p<0.05).In summary,cows fed on mixed forage diet significantly improved milk yield and lactation performance clearly.
文摘Surfactant is widely used in the industry,and its determination is important in both performance and quality control consideration.A liquid chromatography coupling mass spectrometry(LC-MS)method was established for analyzing surfactants in lubricant.Three surfactants,including polyoxyethylene(9)nonyl phenyl ether,polyoxyethylene(10)decanamine ether,and polyoxyethylene(5)oleylamine ether were identified.
文摘To establish HPLC electrospray ionization mass spectrometry (HPLC-ESI MS) method for determination of osthole in food additive.The samples were dipped in methanol overnight and extracted with it by ultrasonic instrument,then the supernatant was send to sampler for detection.Sample was chromatographed using 0.4%HAc solution-MeOH (35:65,by volume) mobile phase on an Xterra MS C18 column.Analyte determination was performed by ESI MS/MS in the multiple reaction monitoring(MRM)mode.The established method of LC-MS/MS determining the concentration of osthole in food additive has the characteristic of strong specificity,high sensitivity and good reproducibility.The linear range of papaverine was 0.001-10 μg/mL,method recovery was 97.42%,RSD was 8.37%,the limit of detection was 1 ng/mL and the limit of quantitation was 0.001 μg/mL.
