scholarly journals Controlling formation of metal ion adducts and enhancing sensitivity in Liquid Chromatography Mass Spectrometry

2020 ◽  
Vol 12 (2) ◽  
pp. 180-192
Author(s):  
Padma Marwah ◽  
Ashok K. Marwah ◽  
Paul V. Zimba
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Formic Acid ◽  
Metal Ion ◽  
Multiple Reaction Monitoring ◽  
Adduct Formation ◽  
Liquid Chromatography Mass Spectrometry ◽  
Electronic Interactions ◽  
Chromatography Mass Spectrometry ◽  
Alkanoic Acids

Formation of metal ion adducts in mass spectrometry, particularly in electrospray ionization liquid chromatography mass spectrometry (ESI-LC-MS), is a nightmare scenario for an analyst dealing with quantitative analysis. We have studied in detail the metal adduct formation and concluded  that the use of fluorinated alkanoic acids along with formic acid and volatile ammonium salts was extremely useful in suppressing metal adduct formation in positive ion mode of ESI-LC-MS. The extremely high electronegativity of fluorine atom and unique electrostatic nature of C—F bond coupled with stereo-electronic interactions with neighboring bonds or lone pairs enables the polyfluorinated alkanoic acids in trapping highly electropositive ions (Na+, K+) thereby letting proton do its job efficiently. Addition of formic acid, trifluoroacetic acid, heptafluorobutyric acid and ammonium acetate was found to be extremely effective in controlling metal ion adducts and producing [M+H]+ ions almost exclusively resulting in significant increase in the sensitivity. This technique has been successfully used in our laboratory for the estimation of targeted and nontargeted analysis of pesticides, marine toxins, drugs and pharmaceuticals etc. in various matrices including environmental waters using liquid chromatography-time of flight mass spectrometer operated in all ion acquisition mode and triple quadruples (QQQ) in multiple reaction monitoring (MRM) mode.

scholarly journals A HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY-MASS SPECTROMETRY METHOD DEVELOPMENT FOR THE QUANTITATIVE DETERMINATION OF ENALAPRIL MALEATE FROM CACO-2 CELL MONOLAYERS

2018 ◽  
Vol 11 (7) ◽  
pp. 89
Author(s):  
Liliya Logoyda
Keyword(s):  
Mass Spectrometry ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Formic Acid ◽  
High Performance ◽  
Liquid Chromatography Mass Spectrometry ◽  
Enalapril Maleate ◽  
Cell Monolayers ◽  
Chromatography Mass Spectrometry

Objective: A simple, rapid high-performance liquid chromatography-mass spectrometry (HPLC MS/MS) method was developed for the determination of enalapril maleate from confluent Caco-2 monolayers and aqueous solution.Methods: Chromatography was achieved on Discovery C18, 50×2.1 mm, 5 μm column. Samples were chromatographed in a gradient mode (eluent A [acetonitrile-water-formic acid, 5: 95:0.1 v/v] and eluent B [acetonitrile-formic acid, 100:0.1 v/v]). The initial content of the eluent B is 0%, which increases linearly by 1.0 min to 100% and 1.01 min returns to the initial 0%. The mobile phase was delivered at a flow rate of 0.4 ml/min into the mass spectrometer ESI chamber. The sample volume was 5 μl.Results: Under these conditions, enalapril maleate was eluted at 1.52 min. According to the Caco-2 test results, enalapril showed low permeability. It should be noted that the recovery value for enalapril is 100.62 %. Low in vitro permeability data for enalapril are in good agreement with the literature data.Conclusion: From results of the analysis, it can be concluded that developed method is simple and rapid for determination of enalapril maleate from confluent Caco-2 monolayers and aqueous solution. Acquired results demonstrate that proposed strategy can be effortlessly and advantageously applied for examination of enalapril from Caco-2 cell monolayers.

scholarly journals NEW METHOD DEVELOPMENT AND VALIDATION FOR THE DETERMINATION OF FEBUXOSTAT IN HUMAN PLASMA BY LIQUID CHROMATOGRAPHY–MASS SPECTROMETRY

2016 ◽  
Vol 8 (9) ◽  
pp. 61 ◽  
Author(s):  
Narottam Pal ◽  
Avanapu Srinivasa Rao ◽  
Pigilli Ravikumar
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Human Plasma ◽  
Method Development ◽  
Multiple Reaction Monitoring ◽  
Internal Standard ◽  
New Method ◽  
Liquid Chromatography Mass Spectrometry ◽  
Chromatography Mass Spectrometry

<p><strong>Objective</strong>:<strong> </strong>To develop a new method and validate the same for the determination of Febuxostat (FBS) in human plasma by liquid chromatography–mass spectrometry (LCMS).</p><p><strong>Methods</strong>:<strong> </strong>The present method utilized reversed-phase high-performance liquid chromatography with tandem mass spectroscopy. Febuxostat D9 (FBS D9) was used as internal standard (IS). The analyte and internal standard were separated from human plasma by using solid phase extraction method. Zorbax Eclipse XDB, C<sub>8</sub>, 100 mm x 4.6 mm, 3.5 µm column was used and HPLC grade acetonitrile, 5 millimolar (mM) ammonium format (80: 20, v/v) as mobile phase, detected by mass spectrometry operating in positive ion and multiple reaction monitoring modes.</p><p><strong>Results</strong>:<strong> </strong>The parent and production transitions for FBS and internal standard were at m/z 317.1→261.0 and 326.1→262.0 respectively. The method was validated for system suitability, specificity, carryover effect, linearity, precision, accuracy, matrix effect, sensitivity and stability. The linearity range was from 20.131 ng/ml to10015. 534 ng/ml with a correlation coefficient of 0.999. Precision results (%CV) across six quality control samples were within the limit. The percentage recovery of FBS and internal standard from matrix samples was found to be 76.57% and 75.03% respectively.</p><p><strong>Conclusion</strong>:<strong> </strong>Present study describes new LC-MS method for the quantification of FBS in a pharmaceutical formulation. According to validation results, it was found to be a simple, sensitive, accurate and precise method and also free from any kind of interference. Therefore the proposed analytical method can be used for routine analysis for the estimation of FBS in its formulation.</p>

scholarly journals Determination of sibutramine and phenolphthalein in weight­loss tea, coffee, and milk by ultra-­performance liquid chromatography mass spectrometry UPLC­-MS/MS

2019 ◽  
Vol 2 (4) ◽  
pp. 42-48
Author(s):  
Than Truong Van ◽  
Duy Nguyen Thanh ◽  
Kiet Ly Tuan ◽  
Vinh Hoang Ngoc ◽  
Hai Chu Van ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Formic Acid ◽  
Gradient Elution ◽  
Ultra Performance Liquid Chromatography ◽  
Distilled Water ◽  
Liquid Chromatography Mass Spectrometry ◽  
Ms Detection ◽  
Chromatography Mass Spectrometry

A rapid, simply and effective method using ultra&shy;performance liquid chromatography coupled to mass spectrometry (MS) detection was developed in order to determine sibutramine and phenolphthalein in weight&shy;loss tea, coffee, and milk. QuEChERS technique was used for cleaning&shy;up sample matrices. The extracts were separated on C18 LC columns using the gradient elution of 0.1% formic acid in distilled water and acetonitrile. The recoveries at the concentration of 50 &micro;g/kg were from 90.1 to 105.8% (with RSDR of 4.04 &shy; 4.24%), from 91.9 to 100.2% (with RSDR of 3.20 &shy; 4.71%), and from 86.5 to 100.5% (with RSDR of 5.17 &shy; 5.49%) for weight&shy;loss tea, coffee, and milk, respectively. Method quantitation limits were of 30 &micro;g/kg.

scholarly journals QUANTITATIVE DETERMINATION OF AMLODIPINE FROM CACO-2 CELL MONOLAYERS BY HIGH-PERFORMANCE LIQUID CHROMATOGRAPHY–MASS SPECTROMETRY/MASS SPECTROMETRY

2018 ◽  
Vol 11 (6) ◽  
pp. 204 ◽  
Author(s):  
Liliya Logoyda
Keyword(s):  
Mass Spectrometry ◽  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Formic Acid ◽  
High Performance ◽  
Liquid Chromatography Mass Spectrometry ◽  
Cell Monolayers ◽  
Chromatography Mass Spectrometry ◽  
Mass Spectrometry Mass Spectrometry

Objective: A simple, rapid high-performance liquid chromatography–mass spectrometry/mass spectrometry (MS/MS) method was developed for the determination of amlodipine from confluent Caco-2 monolayers and from aqueous solution.Methods: Chromatography was achieved on Discovery C18, 50×2.1 mm, 5 μm column. Samples were chromatographed in a gradient mode (eluent A [acetonitrile-water-formic acid, 5:95:0.1 v/v], eluent B [acetonitrile-formic acid, 100:0.1 v/v]). The initial content of the eluent B is 0%, which increases linearly by 1.0 min to 100% and to 1.01 min returns to the initial 0%. The mobile phase was delivered at a flow rate of 0.400 ml/min into the MS electrospray ionization chamber. The sample volume was 5 μl.Results: Under these conditions, amlodipine was eluted at 1.61 min. According to the Caco-2 test results, amlodipine appeared to have moderate to high permeability. Recovery value for amlodipine is 52.33%. Caco-2 permeability values for amlodipine are in agreement with BCS Class I classification for these drugs and their known high bioavailability in humans.Conclusion: A new rapid method was developed for the determination of amlodipine from confluent Caco-2 monolayers and from aqueous solution. Acquired results demonstrate that proposed strategy can be effortlessly and advantageously applied for the examination of amlodipine from Caco-2 cell monolayers.

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