scholarly journals Liquid Chromatographic/Mass Spectrometric Determination of Desmedipham and Phenmedipham and Their Metabolites in Soil

2001 ◽  
Vol 84 (5) ◽  
pp. 1407-1412 ◽  
Author(s):  
Daniela Perret ◽  
Alessandra Gentili ◽  
Stefano Marchese ◽  
Aldo Marino ◽  
Federica Bruno
Keyword(s):  
Reversed Phase ◽  
Soil Types ◽  
Liquid Chromatography Mass Spectrometry ◽  
Reversed Phase Liquid Chromatography ◽  
Soil Suspension ◽  
Simple Method ◽  
Phase Liquid ◽  
Liquid Chromatographic ◽  
Chromatographic Mass

Abstract A simple method is described for the simultaneous determination of residues of 2 carbamate herbicides (phenmedipham and desmedipham) and related metabolites (m-aminophenol, aniline, and m-toluidine) in soil. The analytes are extracted from spiked soils with methanol. The solvent/soil suspension is centrifuged, and the supernatant is directly injected, without any further cleanup, into a reversed-phase liquid chromatography/mass spectrometry apparatus equipped with a TurboIonSpray interface. The method was tested on 5 soils having different physicochemical properties. Recoveries from the soil types, spiked over the range of 50–200 ppb, were essentially quantitative for each analyte. The detection limits of the method are ≤25 ng/g.

Chloramphenicol Extraction from Milk by Using the Diphasic Dialysis Method Followed by Liquid Chromatographic Determination

1994 ◽  
Vol 77 (4) ◽  
pp. 854-856 ◽  
Author(s):  
Javier Bayo ◽  
Miguel A Moreno ◽  
Javier Prieta ◽  
Susana Díaz ◽  
Guillermo Suárez ◽  
...  
Keyword(s):  
Working Conditions ◽  
Chromatographic Determination ◽  
Reversed Phase ◽  
Reversed Phase Liquid Chromatography ◽  
Simple Method ◽  
Dialysis Method ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract An economical, fast, and simple method for the extraction and liquid chromatographic determination of chloramphenicol (CAP) in milk is described. CAP is extracted by using a recently developed membrane-based method named “diphasic dialysis.” CAP is detected and quantitated in the organic solvent used in dialysis without additional cleanup steps by reversed-phase liquid chromatography and UV detection (270 nm). The determination imit of CAP in milk was about 5 μg/L, although as little as 1 μg/L could be detected under optimal working conditions.

scholarly journals Simultaneous Determination of Hyoscine Butylbromide and Ketoprofen in Pharmaceutical Preparations by Spectrophotometric and Liquid Chromatographic Methods

2007 ◽  
Vol 90 (1) ◽  
pp. 102-112 ◽  
Author(s):  
Yasser Shaker El-Saharty ◽  
Fadia H Metwally ◽  
Mohamed Refaat ◽  
Sonia Zaki El-Khateeb
Keyword(s):  
Pharmaceutical Preparations ◽  
Standard Addition ◽  
Reversed Phase ◽  
Reversed Phase Liquid Chromatography ◽  
Hyoscine Butylbromide ◽  
Mathematical Algorithm ◽  
Accuracy And Precision ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A binary mixture of hyoscine butylbromide and ketoprofen was determined by 4 different methods. The first involved determination of hyoscine butylbromide and ketoprofen using the ratio-spectra first-derivative spectrophotometric technique at 211 and 234 nm over the concentration ranges of 2-14 and 5-45 μg/mL with mean accuracies 99.84 ± 0.92 and 99.98 ± 0.64%, respectively. The second method utilized second-derivative spectrophotometry over the concentration ranges of 2-14 and 5-35 μg/mL with mean accuracies 99.32 ± 1.06 and 99.55 ± 1.15%, respectively. The third method was based on the resolution of the 2 components by bivariate calibration depending on a simple and rapid mathematical algorithm and quantitative evaluation of the absorbances at 206 and 254 nm over concentration ranges of 2-16 and 5-35 μg/mL; mean accuracies of 100.21 ± 1.30 and 100.19 ± 1.07% were obtained for hyoscine butylbromide and ketoprofen, respectively. The fourth method was reversed-phase liquid chromatography using 0.05 M ammonium dihydrogen phosphateacetonitrilemethanol (20 + 30 + 6, v/v) as the mobile phase with ultraviolet detection at 220 nm over concentration ranges of 1-90 and 5-70 μg/mL; mean accuracies were 99.92 ± 1.02 and 99.61 ± 0.98%, respectively. The suggested procedures were checked using laboratory-prepared mixtures and were successfully applied for the analysis of pharmaceutical preparations. The methods retained their accuracy and precision when the standard addition technique was applied. The results obtained by applying the proposed methods were statistically analyzed and compared with those obtained by the manufacturer's method.

scholarly journals Determination of Histamine in Tomatoes by Liquid Chromatography/Mass Spectrometry

2000 ◽  
Vol 83 (3) ◽  
pp. 543-548 ◽  
Author(s):  
Elek Bolygo ◽  
Paul A Cooper ◽  
K Michael Jessop ◽  
Frank Moffatt
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Reversed Phase ◽  
Liquid Chromatography Mass Spectrometry ◽  
Reversed Phase Liquid Chromatography ◽  
Absorbance Detection ◽  
Endogenous Histamine ◽  
Order Of Magnitude ◽  
Phase Liquid

Abstract The histamine level in tomato fruits and pastes was determined by 2 orthogonal techniques as a means of comparing accuracy. Close statistical agreement was found between assays for free histamine by capillary electrophoresis (with UV absorbance detection), and for the dansyl derivative by reversed-phase liquid chromatography (LC). Both techniques have adequate sensitivity for the analysis of endogenous histamine in tomatoes, but LC/electrospray tandem mass spectrometry was more sensitive by at least an order of magnitude, down to a level of 0.05 mg/kg.

Liquid Chromatographic Determination of 2-Chloro-4-nitroaniline, 2-Naphthol, and 2,4-Dinitroaniline in D&C Red No. 36

1993 ◽  
Vol 76 (2) ◽  
pp. 287-291 ◽  
Author(s):  
Alan L Scher ◽  
Nicholas C Adamo
Keyword(s):  
Chromatographic Determination ◽  
Reversed Phase ◽  
Calibration Data ◽  
Reversed Phase Liquid Chromatography ◽  
Relative Standard ◽  
Liquid Chromatographic Determination ◽  
Phase Liquid ◽  
Liquid Chromatographic ◽  
Cellulose Column

Abstract A method is described for the determination of the intermediates and a related impurity in D&C Red No. 36 by reversed-phase liquid chromatography. This method may be used to ensure that limits set forth in the Code of Federal Regulations on the amounts of these 3 impurities in the color are not exceeded. The pigment is dissolved in boiling dioxane and then precipitated. The filtrate is chromatographed by isocratic elution, and then the column is washed and reequilibrated. Impurities were identified as 2-chloro-4-nitroaniline (2-CI-4-NA), 2-naphthol, and 2,4-dinitroaniline (2,4-DNA) by comparison of their retention times and spectra with those of standards. Peak area calibrations were linear to at least 0.375% 2-CI-4-NA, 1.25% 2-naphthol, and 0.025% 2,4-DNA, all with zero intercepts. At the specification levels, 99% confidence limits were 0.30 ± 0.006% for 2-CI-4-NA, 1.0 ± 0.03% for 2-naphthol, and 0.020 ± 0.0004% for 2,4-DNA. The limits of determination calculated from calibration data were 0.019% for 2-CI-4-NA, 0.10% for 2-naphthol, and 0.0014% for 2,4-DNA at the 99% confidence level. Recoveries were 100-104% for 2-CI-4-NA added to purified D&C Red No. 36,100% for 2-naphthol, and 100-110% for 2,4-DNA; relative standard deviations were 0.8-3.4%. A survey of certified D&C Red No. 36 samples showed that the batches contained higher levels of intermediates than were determined previously by a cellulose column method in which the pigment was not dissolved.

scholarly journals Determination of Four Fluoroquinolones in Milk by On-Line Immunoaffinity Capture Coupled with Reversed-Phase Liquid Chromatography

1999 ◽  
Vol 82 (3) ◽  
pp. 607-613 ◽  
Author(s):  
Carol K Holtzapple ◽  
Sandra A Buckley ◽  
Larry H Stanker
Keyword(s):  
Raw Milk ◽  
Reversed Phase ◽  
Immunoaffinity Column ◽  
Isocratic Elution ◽  
Reversed Phase Liquid Chromatography ◽  
Sample Matrix ◽  
On Line ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract An automated, on-line immunoaffinity extraction method was developed for the analysis of 4 fluoroquinolones in milk: ciprofloxacin, difloxacin, enrofloxacin, and sarafloxacin. This method involves analyte extraction using an immunoaffinity capture column containing anti-fluoroquinolone antibodies coupled on-line with reversed-phase column chromatography. Liquid chromatographic analyses were performed by isocratic elution using a mobile phase of 2% acetic acid-acetonitrile (85 + 15) and an Inertsil phenyl column with fluorescence detection at excitation and emission wavelengths of 278 and 444 nm, respectively. No significant interferences from the sample matrix were observed, indicating good selectivity with the immunoaffinity column. Recoveries from fortified raw milk samples (5–50 ppb of each fluoroquinolone) ranged from 72 to 90%, with standard deviations of ≤8%.

scholarly journals Determination of Methomyl in Insecticidal Formulations by Reversed-Phase Liquid Chromatography: Collaborative Study

1996 ◽  
Vol 79 (4) ◽  
pp. 941-948
Author(s):  
James E Conaway ◽  
J B Audino ◽  
E Bane ◽  
S K Carrigan ◽  
R Glinsky ◽  
...  
Keyword(s):  
Liquid Chromatography ◽  
Coefficient Of Variation ◽  
Mobile Phase ◽  
Collaborative Study ◽  
Internal Standard ◽  
Reversed Phase ◽  
Reversed Phase Liquid Chromatography ◽  
Phase Liquid ◽  
Liquid Chromatographic

Abstract A reversed-phase liquid chromatographic (LC) method for methomyl was studied. Twelve collaborators analyzed 3 solid and 4 liquid formulations on both a Zorbax octadecylsilane (ODS) column and a similar column of their choice. Methomyl and the internal standard were separated by using a mobile phase consisting of approximately 8% acetonitrile in water, which was monitored at 254 nm. The coefficient of variation on the Zorbax column ranged from 0.70 to 5.23%, while the range on the collaborators' house columns was 1.08 to 6.01%. Results with the Zorbax ODS column fell within the 5% 2-tail limits, and 10 of 11 collaborators' results fell within these limits on house columns. The LC method for determination of methomyl in insecticidal formulations has been adopted first action by AOAC INTERNATIONAL.

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