scholarly journals Microanalysis of β-Lactam Antibiotics and Vancomycin in Plasma for Pharmacokinetic Studies in Neonates

2008 ◽  
Vol 53 (1) ◽  
pp. 75-80 ◽  
Author(s):  
Maurice J. Ahsman ◽  
Enno D. Wildschut ◽  
Dick Tibboel ◽  
Ron A. Mathot
Keyword(s):  
Mass Spectrometry ◽  
Tandem Mass Spectrometry ◽  
Dynamic Range ◽  
Matrix Effects ◽  
Ultra Performance Liquid Chromatography ◽  
Sample Volume ◽  
Reversed Phase ◽  
Pharmacokinetic Studies ◽  
Tandem Mass ◽  
Reliable Quantification

ABSTRACT Rational dosing of antibiotics in neonates should be based on pharmacokinetic (PK) parameters assessed in specific populations. PK studies of neonates are hampered by the limited total plasma volume, which restricts the sample volume and sampling frequency. Available drug assay methods require large sample volumes and are labor-intensive or time-consuming. The objective of this study was to develop a rapid ultra-performance liquid chromatographic method with tandem mass spectrometry detection for simultaneous quantification of amoxicillin, meropenem, cefazolin, cefotaxime, deacetylcefotaxime, ceftriaxone, and vancomycin in 50 μl of plasma. Cleanup consisted of protein precipitation with cold acetonitrile (1:4) and solvent evaporation before reversed-phase chromatographic separation and detection using electrospray ionization tandem mass spectrometry. Standard curves were prepared over a large dynamic range with adequate limits of quantitation. Intra- and interrun accuracy and precision were within 100% ± 15% and 15%, respectively, with acceptable matrix effects. Coefficients of variation for matrix effects and recovery were <10% over six batches of plasma. Stability in plasma and aqueous stocks was generally sufficient, but stability of meropenem and ceftriaxone in extracts could limit autosampler capacity. The instrument run time was approximately 3.50 min per sample. Method applicability was demonstrated with plasma samples from an extracorporeal membrane oxygenation-treated neonate. Different β-lactam antibiotics can be added to this method with additional ion transitions. Using ultra-performance liquid chromatography mass spectrometry, this method allows simple and reliable quantification of multiple antibiotics in 50 μl of plasma for PK studies of neonates.

Determination of 12 Carbamate Insecticides in Typical Vegetables and Fruits by Rapid Multi-Plug Filtration Cleanup and Ultra-Performance Liquid Chromatography/Tandem Mass Spectrometry Detection

2019 ◽  
Vol 58 (2) ◽  
pp. 109-116
Author(s):  
Lili Ma ◽  
Liuwei Zhao ◽  
Jiaqi Wang ◽  
Canping Pan ◽  
Cong Liu ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Matrix Effects ◽  
Solid Phase ◽  
Ultra Performance Liquid Chromatography ◽  
Tandem Mass ◽  
Liquid Chromatography Tandem Mass ◽  
Vegetables And Fruits

Abstract A multiresidue method for determining 12 carbamate pesticides in purple cabbage, orange, watermelon, cucumber, cowpea and Lactuca sativa L. employing multi-plug filtration cleanup (m-PFC) and ultra-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS) was developed. M-PFC was carried out by cleanup at dispersive solid phase extraction (d-SPE), one m-PFC tip-filtration, two m-PFC tip-filtration and other methods (1–3 m-PFC cleanups). Results demonstrated that filtration simplified the cleanup method compared with d-SPE and other m-PFC methods (1–3 m-PFC cleanups). The method validation results showed that the method was linear, selective and accurate. The limits of quantification (LOQs) were 0.05–5.0 μg/kg, and the recoveries were in the range of 70.1–119.9% in different matrices. Although matrix effects were observed, they were successfully compensated using matrix-matched calibration. Finally, the developed method was successfully applied to detect pesticides in real samples.

scholarly journals Approaches to liquid chromatography tandem mass spectrometry assessment of glyphosate residues in wine

2021 ◽  
Author(s):  
L. Pérez-Mayán ◽  
G. Castro ◽  
M. Ramil ◽  
R. Cela ◽  
I. Rodríguez
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Matrix Effects ◽  
Direct Determination ◽  
Reversed Phase ◽  
Multistep Method ◽  
Chromatographic Behavior ◽  
Tandem Mass ◽  
Purification Method

AbstractThe performance of two different analytical methodologies to investigate the presence of glyphosate (GLY) and aminomethylphosphonic acid (AMPA) residues in wine samples was evaluated. Transformation of compounds in their fluorene-9-methyloxycarbonyl derivatives permitted their separation under reversed-phase liquid chromatography with tandem mass spectrometry (LC–MS/MS) determination. Although the wine matrix severely impaired the efficiency of GLY derivatization, this drawback was solved using a molecularly imprinted sorbent for the previous, selective extraction of GLY and AMPA from wine. Alternatively, the use of a strong anionic exchange, polyvinyl alcohol-based LC column, turned to be the most effective alternative for direct determination of both compounds in diluted wine samples. The chromatographic behavior of this column and the magnitude of matrix effects observed during analysis of diluted wine samples were significantly affected by the composition of the mobile phase. Under final working conditions, this column permitted the separation of AMPA and the fungicide fosetyl (which shows common transitions in tandem MS/MS methods), it improved significantly the sample throughput versus extraction-derivatization-purification method, and it allowed the use of solvent-based calibration standards. Both analytical procedures provided similar limits of quantification (LOQs) for GLY (0.5–1.0 ng mL−1), while the multistep method was 8 times more sensitive to AMPA than the direct procedure. GLY residues stayed above method LOQs in 70% of the processed wines; however, concentrations measured in 95% of positive samples remained 100 times below the maximum residue limit (MRL) set for GLY in vinification grapes. Graphical abstract

Pharmacokinetic Study of Multiple Components of Gelsemium elegans in Goats by Ultra-Performance Liquid Chromatography Coupled to Tandem Mass Spectrometry

2020 ◽  
Vol 44 (4) ◽  
pp. 378-390 ◽  
Author(s):  
Jun-Jie Cao ◽  
Kun Yang ◽  
Chong-Yin Huang ◽  
Yu-Juan Li ◽  
Hui Yu ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Pharmacokinetic Study ◽  
Ultra Performance Liquid Chromatography ◽  
Pharmacokinetic Parameters ◽  
Pharmacokinetic Studies ◽  
Tandem Mass ◽  
Veterinary Clinic ◽  
Multiple Components

Abstract Gelsemium elegans (G. elegans) has been used in traditional Chinese medicine. This plant is highly toxic to humans, but can promote the growth of pigs and goats in the veterinary clinic. It is a very complex mixture containing tens or hundreds of different components. Therefore, multiple-component pharmacokinetic studies of G. elegans are a major challenge due to the lack of authentic standards of the components. The purpose of this study was to investigate the plasma pharmacokinetics of multiple components after a single oral dose of G. elegans in goat using a sensitive ultra-performance liquid chromatography coupled to tandem mass spectrometry method for the simultaneous semiquantification of multiple alkaloids without standards. The method was validated in terms of the specificity, LOD, LOQ, linearity, accuracy, precision and matrix effects. To validate the global pharmacokinetic characteristics, the results obtained from the semiquantitative analysis of three authentic compounds (gelsemine, koumine and humantenmine) were compared with the absolute quantification from our recently published method. The results showed that the two methods had similar analytical results, and the obtained values of Tmax, T1/2 and MRT0−t of the three alkaloids were similar between the two methods. In addition, the values of Cmax and AUC0−t of the three alkaloids after normalization were close to the real values, which indicated that this semiquantitative method could be used in the pharmacokinetic study of multiplecomponents. Then the pharmacokinetic parameters of 23 other G. elegans alkaloids in goats were obtained. The results suggested that the gelsedine-type alkaloids were the major active ingredients that predict and explain the efficacy and toxicity of G. elegans.

scholarly journals Ultra performance liquid chromatography-tandem mass spectrometry for the determination of 5-nitroimidazoles and their metabolites in egg

2009 ◽  
Vol 7 (3) ◽  
pp. 267-273 ◽  
Author(s):  
Vytautas Tamošiūnas ◽  
Audrius Padarauskas
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Tandem Mass Spectrometry ◽  
Solid Phase ◽  
Correlation Coefficients ◽  
Ultra Performance Liquid Chromatography ◽  
Reversed Phase ◽  
Tandem Mass ◽  
Sample Extract

AbstractAn ultra performance liquid chromatography (UPLC) coupled to tandem mass spectrometry (MS/MS) procedure was developed for the determination of five 5-nitroimidazoles (dimetridazole, ipronidazole, metronidazole, ronidazole and ternidazole) and three of their metabolites (1-methyl-2-hydroxymethyl-5-nitroimidazole, 1-(2-hydroxyethyl)-2-hydroxymethyl-5-nitroimidazole and 1-methyl-2-(2′-hydroxyisopropyl)-5-nitroimidazole) in egg matrices. Conditions for UPLC separation and electrospray ionization MS/MS in the positive ion mode were optimized. Samples were prepared by liquid-liquid extraction with buffered aqueous 2.5% trichloroacetic acid followed by solid-phase extraction on a Strata-X-C cartridge with reversed-phase and cation-exchange functionalities. The method’s performance was evaluated in accordance with Commission Decision 2002/657/EC, applying the alternative matrix-comprehensive in-house validation approach using specially designed InterVal software. The method was robust against different sample matrix and SPE cartridges, operator change, and changes in sample extract storage. Acceptable apparent recoveries (76 to 109%) were obtained for all analytes. The decision limits (CCα) and detection capabilities (CCα) were within the ranges of 0.19–2.62 and 0.26–4.29 μg kg−1. For all compounds the calibration curve linearity was good with correlation coefficients greater than 0.99. Fifteen eggs and ten whole egg powder samples obtained commercially in Lithuania were analyzed by UPLC-MS/MS; none were found contaminated by 5-nitroimidazoles or their metabolites.

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