scholarly journals Determination of Nonylphenol and Octylphenol Ethoxylates in Effluent by Liquid Chromatography with Fluorescence Detection

1997 ◽  
Vol 80 (2) ◽  
pp. 401-407 ◽  
Author(s):  
Lindsey G Mackay ◽  
Marguerite Y Croft ◽  
David S Selby ◽  
Robert J Wells
Keyword(s):  
Fluorescence Detection ◽  
Nonionic Surfactants ◽  
Solid Phase ◽  
Graphitized Carbon Black ◽  
Phase Extraction ◽  
Matrix Interferences ◽  
Graphitized Carbon ◽  
Cleanup Procedure ◽  
Liquid Chromatographic

Abstract A robust liquid chromatographic (LC) method with fluorescence detection is described for the simultaneous determination of the nonionic surfactants nonylphenol ethoxylates (NPEO) and octylphenol ethoxylates (OPEO) in effluent samples from sewerage treatment plants. The cleanup procedure uses graphitized carbon black solid-phase extraction cartridges. A subsequent derivatization step removes matrix interferences that are no longer fluorescent after acetylation. The efficiency of the method is monitored by inclusion of a surrogate compound designed and synthesized specifically for this purpose. The limit of reporting for the method is 5 μg/L for 100 mL effluent samples. Studies on confirmation of identity of NPEO and OPEO by electrospray LC/mass spectrometry are described.

scholarly journals Application of a Mixed-Mode Solid-Phase Extraction and Cleanup Procedure for LC/MS Determination of Thiabendazole and Carbendazim in Apple Juice

2001 ◽  
Vol 84 (5) ◽  
pp. 1608-1614 ◽  
Author(s):  
Michael S Young ◽  
Michael F Early ◽  
Claude R Mallet ◽  
Jim Krol
Keyword(s):  
Solid Phase Extraction ◽  
Mixed Mode ◽  
Apple Juice ◽  
Solid Phase ◽  
Ionization Mass ◽  
Phase Extraction ◽  
Cleanup Procedure ◽  
Sample Preparation Procedure ◽  
Liquid Chromatographic

Abstract Recently, a mixed-mode solid-phase extraction (SPE) procedure was developed for rapid extraction and cleanup for determination of the fungicides thiabendazole and carbendazim in various fruit juices. This paper reports the application of that sample preparation procedure to the liquid chromatographic/mass spectrometric determination of these fungicides in apple juice with detection by positive electrospray ionization mass spectrometry (ESI/MS). Response was linear for sample concentrations from 2 to 500 μg/L (ppb). Recoveries averaged 74% (9% RSD) for carbendazim and 93% (9% RSD) for thiabendazole. After SPE cleanup, no matrix supression was observed for the ESI+ response for either compound studied. The method was applied to the analysis of incurred residues in 4 store-bought apple juices; carbendazim levels ranged from 10 to 70 μg/L and thiabendazole levels ranged from less than 2 to 130 μg/L.

scholarly journals Determination of Tetracycline Antibiotics in Salmon Muscle by Liquid Chromatography Using Post-Column Derivatization with Fluorescence Detection

2003 ◽  
Vol 86 (5) ◽  
pp. 925-929 ◽  
Author(s):  
Angelina L Pena ◽  
Celeste M Lino ◽  
M Irene N Silveira
Keyword(s):  
Fluorescence Detection ◽  
Solid Phase ◽  
Polymeric Sorbent ◽  
Tetracycline Antibiotics ◽  
Liquid Chromatographic Method ◽  
Limit Of Quantitation ◽  
Ethylenediaminetetracetic Acid ◽  
Cleanup Procedure ◽  
Liquid Chromatographic

Abstract A simple and accurate cleanup procedure using polymeric sorbent was developed for the determination of oxytetracycline (OTC) and tetracycline (TC) residues in salmon muscle. It was applied to the analysis of 20 salmon samples during a month period. The OTC and TC residues were extracted with ethylenediaminetetracetic acid (EDTA)–McIlvaine buffer acidified at pH 4.0 and cleaned up by solid-phase extraction with a polymeric sorbent. The advantages of the polymeric sorbent over the silica-based sorbent in the cleanup of salmon muscle samples are described. A liquid chromatographic method with post-column derivatization and fluorescence detection is proposed because of its sensitivity and specificity. The average recoveries of OTC and TC from muscle salmon tissue fortified at 50, 100, and 200 μg/kg levels, ranged from 83.9 to 93.4% with a coefficient of variation between 4.09 and 5.80%. The limit of quantitation for OTC and TC in salmon muscle was 50 μg/kg.

Liquid Chromatographic Determination of Abamectin in Fruits and Vegetables

1993 ◽  
Vol 76 (3) ◽  
pp. 691-694 ◽  
Author(s):  
Narong Chamkasem ◽  
Michael L Papathakis ◽  
S Mark Lee
Keyword(s):  
Fruits And Vegetables ◽  
Solid Phase ◽  
Ammonium Hydroxide ◽  
Chromatographic Determination ◽  
Phase Extraction ◽  
Fluorescence Detector ◽  
Cleanup Procedure ◽  
Liquid Chromatographic Determination ◽  
Liquid Chromatographic

Abstract A simplified extraction and cleanup procedure was developed for determining abamectin in fruits and vegetables. Abamectin is extracted from sample matrices by acetonitrile, and the acetonitrile phase is separated from the aqueous phase by saturating the extract with sodium chloride. Abamectin is then partitioned into hexane from the acetonitrile, and the hexane layer is cleaned up with an aminopropyl solid-phase extraction (SPE) system. The fluorescent abamectin derivative is formed by dehydration with trifluoroacetic anhydride-1-methylimidazole in dimethylformamide for 1 h at 30°C and with methanolic ammonium hydroxide for another 30 min at 30°C. The derivatized residues are separated from the reaction mixture by a silica SPE. The abamectin derivative is determined by reversedphase liquid chromatography with a fluorescence detector. The method yields recoveries of 85-97% at fortification levels of 10 and 50 μg/kg for orange, pears, spinach, and celery.

scholarly journals Determination of Thiabendazole Residues in Whole Citrus Fruits by Liquid Chromatography with Fluorescence Detection

1996 ◽  
Vol 79 (2) ◽  
pp. 579-582 ◽  
Author(s):  
Rene V Arenas ◽  
Hafizur Rahman ◽  
Nelson A Johnson
Keyword(s):  
Fluorescence Detection ◽  
Solid Phase ◽  
Citrus Fruit ◽  
Extraction Column ◽  
Phase Extraction ◽  
Citrus Fruits ◽  
Average Recovery ◽  
Liquid Chromatographic ◽  
Sensitive Method

Abstract An existing liquid chromatographic (LC) methodfor determination of thiabendazole (TBZ) residues inor on whole green bananas and potatoes was applied to whole, unwashed citrus fruits. The method is applicable for determining TBZ residues in whole oranges,grapefruits, tangerines, and lemons. TBZ is extracted from citrus homogenate with ethyl acetate, and theextract is cleaned up on a cation-exchange, solid-phase extraction column. The purified extract is analyzed by LC with a cation-ex change column and fluorescence detection. Average recovery of TBZ from whole citrus fruits fortified with TBZ at 0.05-20 ppm was 96%. The assay provides a simple, rapid, and sensitive method for monitoring TBZ residues in whole citrus fruit.

Sign in / Sign up

Export Citation Format

Share Document