scholarly journals Multiclass analysis of antibacterial residues in milk using RP-liquid chromatography with photodiode array and fluorescence detection and tandem mass spectrometer confirmation

Talanta ◽  
2012 ◽  
Vol 99 ◽  
pp. 616-624 ◽  
Author(s):  
Isabela Maia Toaldo ◽  
Gabriel Zandonadi Gamba ◽  
Lidia Almeida Picinin ◽  
Gabriel Rubensam ◽  
Rodrigo Hoff ◽  
...  
2015 ◽  
Vol 7 (19) ◽  
pp. 8048-8059 ◽  
Author(s):  
Yong-Lai Feng ◽  
Xiangjun Liao ◽  
Genevieve Grenier ◽  
Nathalie Nguyen ◽  
Peter Chan

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


Author(s):  
SAMBASIVA RAO PURAM ◽  
NITHYA G ◽  
SUBBA RAO NB ◽  
RAMAN BATHEJA

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.


Molecules ◽  
2021 ◽  
Vol 26 (5) ◽  
pp. 1383
Author(s):  
Aurélien Millet ◽  
Nihel Khoudour ◽  
Dorothée Lebert ◽  
Christelle Machon ◽  
Benjamin Terrier ◽  
...  

Rituximab is a chimeric immunoglobulin G1-kappa (IgG1κ) antibody targeting the CD20 antigen on B-lymphocytes. Its applications are various, such as for the treatment of chronic lymphoid leukemia or non-Hodgkin’s lymphoma in oncology, and it can also be used in the treatment of certain autoimmune diseases. Several studies support the interest in therapeutic drug monitoring to optimize dosing regimens of rituximab. Thus, two different laboratories have developed accurate and reproductive methods to quantify rituximab in human plasma: one using liquid chromatography quadripolar tandem mass spectrometer (LC-MS/MS) and the other, liquid chromatography orbitrap tandem mass spectrometer (LC-MS/HRMS). For both assays, quantification was based on albumin depletion or IgG-immunocapture, surrogate peptide analysis, and full-length stable isotope-labeled rituximab. With LC-MS/MS, the concentration range was from 5 to 500 µg/mL, the within- and between-run precisions were <8.5%, and the limit of quantitation was 5 µg/mL. With LC-MS/HRMS, the concentration range was from 10 to 200 µg/mL, the within- and between-run accuracy were <11.5%, and the limit of quantitation was 2 µg/mL. Rituximab plasma concentrations from 63 patients treated for vasculitis were compared. Bland–Altman analysis and Passing–Bablok regression showed the interchangeability between these two methods. Overall, these methods were robust and reliable and could be applied to routine clinical samples.


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