scholarly journals Determination of Imidacloprid and Benzimidazole Residues in Fruits and Vegetables by Liquid Chromatography–Mass Spectrometry after Ethyl Acetate Multiresidue Extraction

2000 ◽  
Vol 83 (3) ◽  
pp. 748-755 ◽  
Author(s):  
Amadeo R Fernández-Alba ◽  
Ana Tejedor ◽  
Ana Agüera ◽  
Mariano Contreras ◽  
Juan Garrido
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Ethyl Acetate ◽  
Fruits And Vegetables ◽  
Monitoring Program ◽  
Reversed Phase ◽  
Food Samples ◽  
Ionization Mass ◽  
Vegetables And Fruits

Abstract A simple and sensitive method based on liquid chromatography–atmospheric pressure ionization–mass spectrometry is described for the determination of 4 benzimidazole pesticides (carbendazim, thiabendazole, benomyl, and thiophanate-methyl) and imidacloprid in vegetables and fruits. Food samples were typically extracted with ethyl acetate to draw the analytes into the organic phase. No cleanup step was necessary before injection into the liquid chromatographic (LC) system with electrospray mass spectrometric detection. The analytes were separated on a reversed-phase C8LC column. Limits of detection for the compounds were in the μg/L range. Results are reported for validation studies with fortified pear and tomato samples and for residues of the target compounds found in the pesticide residue monitoring program during 1998.

Coupling of capillary-channeled polymer (C-CP) fibers for reversed phase liquid chromatography and ESI-MS for the determination of proteins in a urine matrix

2016 ◽  
Vol 8 (48) ◽  
pp. 8410-8419 ◽  
Author(s):  
Lei Wang ◽  
Marissa A. Pierson ◽  
R. Kenneth Marcus
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Reversed Phase ◽  
Ionization Mass ◽  
Reversed Phase Liquid Chromatography ◽  
Esi Ms ◽  
Detection Mode ◽  
Phase Liquid ◽  
Urine Matrix

Electrospray ionization mass spectrometry (ESI-MS) analysis provides a great deal of analytical information as a detection mode when coupled with liquid chromatography (LC) and capillary electrophoresis (CE) separations of proteins.

scholarly journals Determination of the Appetite Suppressant P57 in Hoodia gordonii Plant Extracts and Dietary Supplements by Liquid Chromatography/Electrospray Ionization Mass Spectrometry (LC-MSD-TOF) and LC-UV Methods

2006 ◽  
Vol 89 (3) ◽  
pp. 606-611 ◽  
Author(s):  
Bharathi Avula ◽  
Yan-Hong Wang ◽  
Rahul S Pawar ◽  
Yatin J Shukla ◽  
Brian Schaneberg ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Dietary Supplements ◽  
Reversed Phase ◽  
Ionization Mass ◽  
Active Constituent ◽  
Appetite Suppressant ◽  
Hoodia Gordonii ◽  
Relative Standard

Abstract Hoodia gordonii is traditionally used in South Africa for its appetite suppressant properties. P57AS3 (P57), an oxypregnane steroidal glycoside, is the only reported active constituent from this plant as an appetite suppressant. Effective quality control of these extracts or products requires rapid methods to determine P57 content. New methods of liquid chromatography/mass spectrometry (LC/MS) and LC-UV for analysis of P57 from H. gordonii have been developed. The quantitative determination of P57 was achieved with a Phenomenex Gemini (Torrance, CA) reversed-phase column using gradient mobile phase of water and acetonitrile, both containing 0.1% acetic acid. The method was validated for linearity, repeatability, and limits of detection and quantification. Good results were obtained in terms of repeatability (relative standard deviation <5.0%) and recovery (98.5103.5%). The developed methods were applied to the determination of P57 for H. gordonii plant samples, one related genus (Opuntia ficus-indica), and dietary supplements that claim to contain H. gordonii.

scholarly journals Determination of Residues of Pirimicarb and Its Desmethyl and Desmethylformamido Metabolites in Fruits and Vegetables by Liquid Chromatography–Electrospray/Mass Spectrometry

2000 ◽  
Vol 83 (3) ◽  
pp. 735-741 ◽  
Author(s):  
James R Startin ◽  
Mark D Sykes ◽  
John C Taylor ◽  
Simon J Hird ◽  
Kirsty Jackson ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Electrospray Mass Spectrometry ◽  
Fruits And Vegetables ◽  
Limit Of Detection ◽  
Signal To Noise Ratio ◽  
Reversed Phase ◽  
Green Beans ◽  
Broad Beans

Abstract A method was developed for the simultaneous determination of residues of pirimicarb (I) and its desmethylformamido (II) and desmethyl (III) metabolites in plums, peas, green beans, broad beans, carrots, and swedes. The compounds were extracted with ethyl acetate and determined, without cleanup, by reversed-phase liquid chromatography and electrospray mass spectrometry (MS). MS and MS/MS were used concurrently to monitor the protonated molecules and their common collision-induced dissociation product. The limit of detection (signal-to-noise ratio of >3) was 1 ng/mL, corresponding to crop concentrations of <0.0015 mg/kg. All 3 compounds were determined in plums, broad beans, and green beans by MS without interference. Interferences which affected the determination of desmethylformamido-pirimicarb in peas, and to a lesser extent in carrots and swedes, were eliminated by MS/MS. Recoveries for all 3 compounds, at 0.05 mg/kg for plums and 0.005 mg/kg for other commodities, were in the range 83–124%. No interconversion of I, II and III, occurred during extraction, and the compounds were stable in extracts for ≥7 days under appropriate conditions.

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