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
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.
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.
