Determination of formic acid in urine of workers occupationally exposed to formaldehyde

2010 ◽  
Vol 196 ◽  
pp. S74 ◽  
Author(s):  
C. Mautempo ◽  
M.D.L. Bastos ◽  
F. Carvalho ◽  
F. Remião ◽  
H. Carmo ◽  
...  

Author(s):  
Shixing Zhu ◽  
Jiayuan Zhang ◽  
Zhihua Lv ◽  
Mingming Yu

Background: Apigenin, a natural plant flavone, has been shown to possess a variety of biological properties. Objective: In this report, a highly selective and sensitive LC-MS/MS method was developed and validated for the determination of apigenin in rat plasma. Methods: Analysts were separated on the HSS T3 column (1.8 μm 2.1×100 mm) using acetonitrile and 0.1% formic acid in 2 mM ammonium acetate buffer at a supply rate of 0.200 mL/min as eluent in gradient model. Results: Plasma samples were treated by protein precipitation using acetonitrile for the recovery ranging from 86.5% to 90.1% for apigenin. The calibration curves followed linearity in the concentration range of 0.50-500 ng/mL. The inter-day and intra-day precisions at different QC levels within 13.1% and the accuracies ranged from -10.6% to 8.6%. Conclusion: The assay has been successfully applied to the pharmacokinetic study of apigenin in rats.



Separations ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 78
Author(s):  
Sevasti Karampela ◽  
Jessica Smith ◽  
Irene Panderi

An ever-increasing need exists within the forensic laboratories to develop analytical processes for the qualitative and quantitative determination of a broad spectrum of new psychoactive substances. Phenylethylamine derivatives are among the major classes of psychoactive substances available on the global market and include both amphetamine analogues and synthetic cathinones. In this work, an ultra-high-performance liquid chromatography-positive ion electrospray ionization tandem mass spectrometric method (UHPLC-ESI-MS/MS) has been developed and fully validated for the determination of 19 psychoactive substances, including nine amphetamine-type stimulants and 10 synthetic cathinone derivatives, in premortem and postmortem whole blood. The assay was based on the use of 1 mL premortem or postmortem whole blood, following solid phase extraction prior to the analysis. The separation was achieved on a Poroshell 120 EC-C18 analytical column with a gradient mobile phase of 0.1% formic acid in acetonitrile and 0.1% formic acid in water in 9 min. The dynamic multiple reaction monitoring used in this work allowed for limit of detection (LOD) and lower limit of quantitation (LOQ) values of 0.5 and 2 ng mL−1, respectively, for all analytes both in premortem and postmortem whole blood samples. A quadratic calibration model was used for the 12 quantitative analytes over the concentration range of 20–2000 ng mL−1, and the method was shown to be precise and accurate both in premortem and postmortem whole blood. The method was applied to the analysis of real cases and proved to be a valuable tool in forensic and clinical toxicology.



2013 ◽  
Vol 634-638 ◽  
pp. 1586-1590
Author(s):  
Su Fang Wang ◽  
Shou Jie Zhang ◽  
Chun Hong Dong ◽  
Guo Qing Wang ◽  
Jun Feng Guo ◽  
...  

A method for simultaneous determination of residuals of four herbicides and pesticides, simazine, carboxin, diflubenzuron and rotenone, in Chinese green tea was developed. In the proposed method, the tea powder was placed in a centrifuge tube with a plug, extracted in saturated aqueous sodium chloride solution and acetonitrile, agitated using vortex oscillator, and then centrifuged 5 min at 4000 rpm. The supernatant solution was purified by primary secondary amine (PSA) sorbent, C18 power, and graphitized carbon black powder, respectively. Then the purified extracts were dissolved with acetonitrile:0.1% formic acid aqueous solution (40:60, V/V) and agitated, filtered using a syringe with 0.22 μm nylon filter prior to UPLC-MS/MS analysis. The UPLC analysis was performed on an ACQUITY UPLC® HSS T3 column (2.1 mm×100 mm, 1.8 µm), using acetonitrile-0.1% formic acid as mobile phase with the flow rate as 0.3 mL•min-1. Injection volume was 10 µL. Positive ionization mode was applied, and the ions were monitored in the multiple reaction monitoring (MRM) mode with curtain gas 0.069 MPa, collision gas 0.052 MPa, ESI ion spray voltage 5000 V, temperature 550 °C, nebulizer gas 0.24 MPa, and turbo gas 0.28 MPa. The limit of detection (LOD) and limit of quantitation (LOQ) of the proposed method are 1 μg•kg-1and 5 μg•kg-1, respectively. The average recoveries of the four pesticides at 10, 20, and 50 µg•kg-1spiking levels range from 77.4% to 95.3%. TheSupersSuperscript textcript textrelative standard deviation (RSD) (n=6) range form 11.83% to 4.52%.



2021 ◽  
Vol 37 (2) ◽  
pp. 321-329
Author(s):  
Nilesh Takale ◽  
Neelakandan Kaliyaperumal ◽  
Gopalakrishnan Mannathusamy ◽  
Rajarajan Govindasamy

The Pharmaceutical industry uses formic acid in the manufacturing of various drug substances or API. At the time of manufacturing of API formic acid is use as an oxidizing agent. Formic acid is the simplest carboxylic acid. It also called methanoic acid.Formic acid present in API at high concentrations is very hazardous but in low concentrations is very beneficial. The developed and validated method was short, precise, cost effective and reproducible with FID detector and easy to use. The method is a selective and superficial analytical method for determination of formic acid in different drug substances. We report here the development and validation study of headspace gas chromatographic method to determine formic acid in different drug substances we are reported here. As per this method, the drug sample was dissolved in 0.1% (v/v) of concentrated sulfuric acid in isopropyl alcohol (IPA) in a GC headspace vial and 0.1% (v/v) of concentrated sulfuric acid in isopropyl alcohol used as a diluent. A AB-Inowax capillary column (30 m x 0.32 mm I.D. and 0.5 µm film thickness) was used under gradient conditions with FID. The formic acid peak was well separated from all other solvents that are used in synthesis of particular drug substance. The LOD and LOQof the method for formic acid are 82 ppm and 249 ppm respectively. Formic acid are low toxic class-III solvent as per ICH guideline.



Author(s):  
Liliya Logoyda

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.



Author(s):  
Silmara Bianchi ◽  
Clarice Amaral ◽  
Caroline Silva ◽  
Ana Rita Nogueira


1985 ◽  
Vol 18 (14) ◽  
pp. 1733-1742
Author(s):  
Anna C. P. Baptista ◽  
Henrique A. Salles andrade


2009 ◽  
Vol 92 (2) ◽  
pp. 680-688 ◽  
Author(s):  
Pei Chen ◽  
Renata Atkinson ◽  
Wayne R Wolf

Abstract The purpose of this study was to develop a single-laboratory validated (SLV) method using high-performance liquid chromatography with different detectors diode array detector (DAD); fluorescence detector (FLD); and mass spectrometry (MS) for determination of 7 B-complex vitamins (B1-thiamin, B2-riboflavin, B3-nicotinamide, B6-pyridoxine, B9-folic acid, pantothenic acid, and biotin) and vitamin C in multivitamin/multimineral dietary supplements. The method involves the use of a reversed-phase octadecylsilyl column (4 m, 250 2.0 mm id) and a gradient mobile phase profile. Gradient elution was performed at a flow rate of 0.25 mL/min. After a 5 min isocratic elution at 100 A (0.1 formic acid in water), a linear gradient to 50 A and 50 B (0.1 formic acid in acetonitrile) at 15 min was employed. Detection was performed with a DAD as well as either an FLD or a triple-quadrupole MS detector in the multiple reaction monitoring mode. SLV was performed using Standard Reference Material (SRM) 3280 Multivitamin/Multimineral Tablets, being developed by the National Institute of Standards and Technology, with support by the Office of Dietary Supplements of the National Institutes of Health. Phosphate buffer (10 mM, pH 2.0) extracts of the NIST SRM 3280 were analyzed by the liquid chromatographic (LC)-DAD-FLD/MS method. Following extraction, the method does not require any sample cleanup/preconcentration steps except centrifugation and filtration.



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