Famphur

Materials. HPLC-grade acetonitrile, water, hexafluorobenzene (99%) and chlorobenzene (99.9%), iodobenzene (>99%) and fluorobenzene (>99.5%) were obtained from Sigma-Aldrich (Buchs, Switzerland), and toluene (99.85%) and acetone (99.9%) from Acros Organics (Geel, Belgium). Analytical-grade pesticide and drug standards were purchased from Sigma-Aldrich, and were: ametryn, atrazine, prometon, prometryn, propazine, simazine, terbutryn, disulfoton, famphur, parathion, parathion-methyl, phorate, sulfotep, thionazin, triethyl thiophosphate, dimethoate, metolachlor, pyrimethanil, malathion, cyprodinil, flusilazole, cyproconazole, trifloxystrobin, quinoxyfen, tebuconazole, pyriproxyfen, pyridaben, difenoconazole, azoxystrobin, diazepam, cocaine, methadone, desipramine, imipramine, MDMA, ketamine, lidocaine and fentanyl. Phenanthrene-d10, pyrene-d10, and a polycyclic aromatic hydrocarbon mix (CRM 47930) were purchased from Sigma-Aldrich.

Materials. HPLC-grade water and acetonitrile and dimethyldichlorosilane (DMDCS, 5% in toluene) were obtained from Sigma-Aldrich (Buchs, Switzerland). PESTANAL© analyticalgrade standards were purchased from Sigma-Aldrich: famphur, parathion, parathion-met, sulfotep, thionazin, ametryn, atrazine, atrazine-D 5 , metolachlor, prometon, prometryn, terbutryn, propazine, simazine, pyrimethanil, cyproconazole, quinoxyfen, flusilazole, trifloxystrobin, azoxystrobin, pyridaben, pyraclostrobin, pyriproxyfen, tebuconazole, cyprodinil, difenoconazole and malathion. Organic grape juice was purchased at local grocery stores in Zurich (Switzerland) and in Waterloo (ON, Canada). PDMS/DVB/PDMS coatings were prepared in-house following the procedure described by Souza-Silva et al. 16 Sample preparation. Individual pesticide standard stock solutions were prepared at a concentration of 5 mg/mL in acetonitrile, and stored at -20 °C. A mix of the pesticides at 100 µg/mL in acetonitrile was prepared from the stock solutions. Diluted solutions used for SPME analysis were prepared in ACN from the mix and were stored at a temperature of 4 °C.
The grape juice samples were spiked with an aliquot of the pesticides standards mixtures, always keeping the total amount of solvent spiked in the matrix below 1% (v:v).