scholarly journals Rapid liquid chromatography/tandem mass spectrometer (LCMS) method for clozapine and its metabolite N-desmethyl Clozapine (Norclozapine) in human serum

2009 ◽  
Vol 23 (6) ◽  
pp. 394-398 ◽  
Author(s):  
L.V. Rao ◽  
M.L. Snyder ◽  
G.M. Vallaro
Keyword(s):  
Liquid Chromatography ◽  
Human Serum ◽  
Mass Spectrometer ◽  
Tandem Mass ◽  
Tandem Mass Spectrometer ◽  
Liquid Chromatography Tandem Mass

Determination of 18 phthalate metabolites in human urine using a liquid chromatography-tandem mass spectrometer equipped with a core–shell column for rapid separation

2015 ◽  
Vol 7 (19) ◽  
pp. 8048-8059 ◽  
Author(s):  
Yong-Lai Feng ◽  
Xiangjun Liao ◽  
Genevieve Grenier ◽  
Nathalie Nguyen ◽  
Peter Chan
Keyword(s):  
Liquid Chromatography ◽  
Mass Spectrometer ◽  
Human Urine ◽  
Core Shell ◽  
Tandem Mass ◽  
Rapid Separation ◽  
Tandem Mass Spectrometer ◽  
Phthalate Metabolites ◽  
Liquid Chromatography Tandem Mass

Phthalates are a group of chemicals used in a variety of products worldwide.

scholarly journals RAPID, METHOD FOR DETERMINATION OF METFORMIN AND CANAGLIFLOZIN IN PLASMA BY LIQUID CHROMATOGRAPHY-TANDEM MASS SPECTROMETER, APPLICATION TO BIOEQUIVALENCE STUDY

2019 ◽  
pp. 93-97
Author(s):  
SAMBASIVA RAO PURAM ◽  
NITHYA G ◽  
SUBBA RAO NB ◽  
RAMAN BATHEJA
Keyword(s):  
Liquid Chromatography ◽  
Mass Spectrometer ◽  
Mobile Phase ◽  
Solid Phase ◽  
Bioequivalence Study ◽  
Simultaneous Estimation ◽  
Tandem Mass ◽  
Tandem Mass Spectrometer ◽  
Liquid Chromatography Tandem Mass

Objective: The objective of the study was to develop and validate a rapid selective bioanalytical method for the simultaneous determination of metformin and canagliflozin in plasma by liquid chromatography-tandem mass spectrometer (LC-MS/MS) to facilitate bioequivalence study sample analysis. Stock solutions and spiking solutions were prepared accurately in methanol and 80% methanol in water, respectively. Methods: Chromatography monitored using Analyst 1.6.2 software. Method was found selective, no matrix effect, reproducible and consistent recovery, accuracy, precision, and stable in aqueous as well as extracted/matrix samples. Method found linear over the range 10–2000 ng/ml for metformin and 30–6000 ng/ml for canagliflozin. The method is successfully applied to analyze samples collected in a bioequivalence study after administration of metformin/canagliflozin 1000/150 mg to 24 healthy male volunteers. Results: Extraction was carried out using a simple solid phase extraction using mobile phase elution. 5 μl sample delivered as injection volume in 1.000 ml/min isocratic mobile phase flow on turbo ion electron spray technique for positive mode on API 4000 MS. Discussion: Chromatography achieved within 3 min using a mobile phase containing acetonitrile and 10 mM ammonium formate buffer in a ratio of 70:30 on chromolith C18 analytical column. Q1/Q3 are 130.1/70.1, 136.3/77.1, 462.2/267.2 (with ammonium adduct), and 466.4/267.1 for metformin, metformin D6, canagliflozin, and canagliflozin D4, respectively. Conclusion: Rapid, sensitive method for the simultaneous estimation of metformin and canagliflozin in plasma by LC-MS/MS is successfully developed, validated and applied to analyze 960 unknown samples of a bioequivalence study. Incurred sample reanalysis was revealed great reproducibility.

scholarly journals The Dirt and The Bees: The Epidemiology of Neonicotinoids

Elements ◽  
2016 ◽  
Vol 12 (1) ◽  
Author(s):  
Katelyn Johnson
Keyword(s):  
Liquid Chromatography ◽  
Mass Spectrometer ◽  
Honey Bees ◽  
Aquatic Organisms ◽  
Aquatic System ◽  
Tandem Mass ◽  
Tandem Mass Spectrometer ◽  
Sediment Samples ◽  
Solid Extraction ◽  
Liquid Chromatography Tandem Mass

Neonicotinoids, such as Thiamethoxam (TMX ) and its metabolite Clothianidin (CLO ), are widely used insecticides commonly coated on planting seeds. Due to their contamination of waterways, their accumulation in aquatic organisms is often lethal and possibly contributes to the decline of honey bees. In order to understand the distribution of TMX and CLO in an agricultural-urban-mixed impacted stream, their levels in sediments from seven locations along Stroubles Creek, Blacksburg were investigated. The sediment samples were extracted using liquid/solid extraction, cleaned up using PSA , and analyzed on a liquid chromatography-tandem mass spectrometer (UPLC /MS /MS). The following study suggests the ability of insecticide to travel through the soil to the creek, shows lower levels of CLO than TMX , and reveals the necessity of further research in regards to CLO concentration. Overall, this study re-affirms that TMX can travel into an adjacent aquatic system, which honey bees use for their water foraging needs.

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