Clomeprop metabolite

Analyte Clomeprop Metabolite (derivative) Diflufenican Inabenfide Mefenacet Flutoranil Mepronil ... 

Since the metabolite of clomeprop, 2-(2,4-dichloro-3-methylphenoxy)propionic acid, and inabenfide could not be directly determined by GC, they are derivatized to a more stable compound with diazomethane for the metabolite of clomeprop or with anhydrous chloroacetic acid for inabenfide. 

For example, the metabolite of clomeprop is determined by the following procedures. Water (20 mL) is added to 10 g of sample and then the mixture is allowed to stand at room temperature for 2h. To the mixture, 4mL of IN hydrochloric acid and 100 mL of acetone are added and shaken for 30 min. The filtrate is extracted twice with 50 mL of dichloromethane after 50 mL of water and 5 g of sodium chloride have been added. The combined dichloromethane extract is concentrated, the final residue is dissolved in 50 mL of dichloromethane, then the dichloromethane layer is rinsed with alkaline and acid and extracted twice with 50 mL of 1 % sodium bicarbonate-5% sodium chloride (1 1, v/v) for 5 min. To the combined aqueous layer, 6 N hydrochloric acid is added and extracted twice with 50 mL of dichloromethane for 5 min. The organic extract is concentrated after drying with anhydrous sodium... 

Several methods can be used for the residue analysis of anilides, especially gas chro-matography/mass spectrometry (GC/MS) and liquid chromatography/mass spectrometry (LC/MS). GC/ECD or GC/NPD for the determination of anilides has generally been used except for the unstable metabolites of naproanilide and clomeprop, which are determined by HPLC/UV, HPLC/FL or GC/ECD after derivatization. 

The recoveries of clomeprop and its metabolite DMPA in soil after extraction with acetonitrile-water (4 1, v/v) by HPLC/UV (234 nm) are >90% The recoveries of propanil and its metabolite, 3,4-dichloroaniline, in soil are 95 and 76%, respectively, by Soxhlet extraction and LC/PAD determination. Diflufenican is added to soil in the range 0.002-0.008 mg kg to validate the method developed by Conte et al. The average recovery from the soil by this method is 92 5%. 

To determine simultaneously the parent compounds and the metabolites of ethoben-zanid and clomeprop, each parent compound is extracted with n-hexane from the water sample, and the metabolites are extracted with diethyl ether after acidification of the remaining aqueous layer. 

Thus, organic solvent extraction methods for the extraction of pesticides from water samples can be replaced by the SPE method using Ci8 and PS-2. Ethobenzanid, clomeprop, naproanilide and their acidic metabolites are determined by a multi-residue analytical method using Cig or PS-2 cartridge extraction after acidification of the water samples with hydrochloric acid or other acidic media, followed by HPLC or LC/MS detection. 

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