Determination of ethephon residues in water by gas chromatography with cubic mass spectrometry after ion-exchange purification and derivatisation with N-(tert-butyldimethylsilyl)-N-methyltrifluoroacetamide.
An analytical method has been developed for the determination of residues of ethephon (2-chloroethyl phosphonic acid) in drinking and surface water. The procedure is based on de-ionisation with an anion/cation-exchange resin, solid phase extraction by means of anion-exchange polystyrene-divinylbenzene extraction disks, elution with a mixture of methanol and 10 M hydrochloric acid (98/2, v/v), redisolution into acetonitrile after evaporation and silylation with N-(tert-butyldimethylsilyl)-N-methyltrifluoroacetamide (MTBSTFA). Quantification is performed by gas chromatography with ion-trap cubic mass spectrometric detection in the electron impact mode (GC-EI-MS3). Method validation was conducted using samples of mineral, tap, and river water that were fortified with ethephon at concentration levels ranging from 0.1 to 1.0 microg/L. The mean recovery from all the fortified samples (n = 36) amounted to 88% with a relative standard deviation of 17%. The method, therefore, was shown to allow accurate determination of ethephon residues in drinking and surface water with a limit of quantification of 0.1 microg/L.
Royer
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A
Groupement Interrégional de Recherche sur les Produits Agropharmaceutiques, Angers Technopole, 8 rue H. Becquerel, F-49070 Beaucouzé, France. a.royer.girpa@wanadoo.fr
Laporte
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F
Bouchonnet
S
S
Communal
P-Y
PY
D000081:Acetamides; D002852:Chromatography, Ion Exchange; D005463:Fluoroacetates; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D009943:Organophosphorus Compounds / Q000032:analysis*; D017646:Organosilicon Compounds / Q000737:chemistry; D014269:Trifluoroacetic Acid / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*
D000081:Acetamides; D005463:Fluoroacetates; D009943:Organophosphorus Compounds; D017646:Organosilicon Compounds; D014874:Water Pollutants, Chemical; C059151:N-methyl-N-(tert-butyldimethylsilyl)trifluoroacetamide; D014269:Trifluoroacetic Acid; C005073:ethephon