Determination of thyreostats in bovine urine using ultra-high performance liquid chromatography-tandem mass spectrometry

Five thyreostats(TSs),namely tapazole,thiouracil,methylthiouracil,propylthiouracil,and phenylthiouracil,were determined in bovine urine using ultra-high performance liquid chromatography-tandem mass spectrometry(UHPLC-MS/MS)in positive electrospray ionization mode.Extraction and clean-up were achieved using a ChemElut cartridge with tert-butyl methyl ether,without a derivatization step.Separation was achieved on an Acquity UPLC SS T3 column.The mobile phase was acetonitrile and water containing 0.2%(v/v)formic acid.The mass spectrometer was operated in multiple reaction monitoring mode.Urine samples were spiked with TS solution at levels corresponding to 5,10,15,and 20μg/L.The accuracy(internal standard corrected)ranged from 92%to 107%,with a repeatability precision(relative standard deviation,RSD)less than 15%for all five analytes.The RSDs within-laboratory reproducibility was less than 26%.The decision limits(CCα)and detection capabilities(CCβ)were obtained from a calibration curve and were in the ranges of 3.1-6.1μg/L and 4.0-7.4μg/L,respectively.The CCαand CCβvalues were below the recommended concentration,which was set at 10μg/L.The results show that the described method is suitable for the direct detection of TSs in bovine urine.This method can also be used to determine TSs in porcine urine.

Ultra-High-Performance Liquid Chromatograph with Triple-Quadrupole Mass Spectrometer Quantitation of Twelve Phenolic Components in Different Parts of Sarcandra glabra

Objective:The study objective was to determine phenolic components for the quality control(QC)of cultivated Sarcandra glabra(Thunb.)Makino(S.glabra).Materials and Methods:A sensitive,ultra-high-performance liquid chromatography-tandem mass spectrometric method for the simultaneous determination of 12 phenolic components has been developed.Six caffeoylquinic acids,two caffeoylshikimic acids,and four flavanonol glucosides were selected for the comprehensive analysis of distribution in different parts(root,stem,and leaf).Results:Twelve phenolic components were linear in the concentration range of 0.005–5.0μg/mL(R^(2)>0.995).The relative standard deviation of intra-day and inter-day precision across three validation runs over the entire concentration range was<5%.The recovery determined was within 5%in terms of relative error.Our results showed that the 12 phenolic compounds were mainly distributed in leaves and stems far more than those in roots.Conclusions:This study provided an ultra-high-performance liquid chromatograph with triple-quadrupole mass spectrometer quantitative method of 12 phenolic components for the QC of cultivated S.glabra.It was found that the phenolic components were significantly accumulated in the aerial parts(stems and leaves)of cultivated S.glabra.

Development of a Rapid and Simultaneous Detection Method for Buprenorphine, Norbuprenorphine and Naloxone in Human Plasma Using Ultra-high Performance Liquid Chromatography- tandem Mass Spectrometer with Solid-phase Extraction

A simultaneous method was successfully established and validated for the separation and determination of bu- prenorphine （BP）, its primary metabolite, nor-buprenorphine （NBP） and a proposed co-formulate, naloxone （NLX） in human plasma. The method used buprenorphine-d4 （BP-D4）, nor-buprenorphine-d3 （NBP-D3）, naltrexone （NTX） as internal standards （ISs）. 100 μL of plasma sample fortified with the ISs was cleaned up by solid-phase extraction （SPE）, and was then separated on a Waters AcquityTM BEH C18 column with gradient elution using methanol and water （containing 0.2% formic） at a flow rate of 0.25 mL·min^-1. The mass spectrometer was used for detection and was operated in the positive electrospray ionization with multiple reaction monitoring （MRM） mode. The three compounds were effectively separated in 5 min. The linear ranges of the compounds were 0.1--25, 0.25--25 and 0.05--25 ng·mL^-1 for BP, NBP and NLX, respectively, with r≥0.9935. The method had high sensitivity （the lim- its of detection were 0.02, 0.1 and 0.01 ng.mL-1 for BP, NBP and NLX, respectively） and high recoveries （≥97.6%）. The result was shown to be linear and satisfactorily met current acceptance criteria for validation of bio- analytical method： intra and inter assay precisions within the required limits of ≤25% RSD. The LOQs fulfilled the LOQ requirements： precision≤25% RSD, and was fully validated according to the State Food and Drug Administration （SFDA） regulations. The results demonstrated that ultra-high performance liquid chromatography- tandem mass spectrometer （UPLC-MS/MS） with SPE was a powerful detection tool and contributed to pharmaceutical analysis in biological matrices.

Pharmacokinetic and Relative Bioavailability of Three Secoiridoid Glycosides in Beagle Dog Plasma After Oral Administration of Conventional and Enteric-Coated Capsules of Gentianella acuta Extract

Objective:To simultaneously investigate the pharmacokinetics of gentiopicroside,sweroside,and swertiamarin,which are constituents of Gentianella acuta,by developing and validating a simple,sensitive,and fast ultra-high-performance liquid chromatography–tandem mass spectrometry method.Materials and Methods:Blood samples were collected from the forward limb veins of six beagle dogs following oral gavage with G.acuta,the whole plant extract(39.90 mg/kg).Plasma samples were processed using liquid–liquid extraction.The analytes and paeoniflorin(internal standard[IS])were separated using an Acquity?UPLC ethylene bridged hybrid amide column(2.1 mm×100 mm,1.7μm)with isocratic elution using a mobile phase consisting of acetonitrile and 0.1%formic acid in water(80:20,v/v)at a flow rate of 0.4 mL/min.Quantification was performed using multiple reaction monitoring of the fragmentation transitions at m/z 401.1→179.0,403.1→195.0,419.1→179.0,and 525.2→449.1 for gentiopicroside,sweroside,swertiamarin,and the IS,respectively.Results:The linearity of the analytical response was good and the calibration curves were linear over concentration ranges of 1.20–192.0,0.40–159.0,and 0.20–209.3 ng/mL for gentiopicroside,sweroside,and swertiamarin,respectively.The extraction recovery was in the range of 84.72%–91.34%,84.58%–93.43%,and 82.75%–91.37%for gentiopicroside,sweroside,and swertiamarin,respectively.Conclusions:The method was successfully used to evaluate the pharmacokinetic parameters of gentiopicroside,sweroside,and swertiamarin in beagle dogs.