Prometryn

Atrazine, Atrazine-desethyl (DEA), Atrazine-desisopropyl (DIA), bromacil, carbendazim, chlorpyrifos, diuron, imazalil, linuron, metolachlor, prometryn, simazine, terbumeton, terbumeton-desethyl (TED) , terbuthylazine, terbuthylazine-desethyl (TD), terbutryn, thiabendazole, 3,4-dichloroaniline (3,4-DCA), 3,5,6-trichloro-2-pyridinol (TCP) were purchased from Sigma-Aldrich (Madrid, Spain), with a purity higher than 97%. The list of pesticides and TPs available for this study, as well as some physicochemical properties, are listed in Supplementary Material (Table SM1).
HPLC-grade methanol (MeOH), acetone (pesticide residue analysis quality) and formic acid (98-100%, LC-MS grade), were supplied by Scharlau S.L (Barcelona, Spain).
HPLC-grade water (resistivity of 18 MΩ cm) was obtained by purifying demineralised water (Millipore Ltd., Bedford, MA, USA).
Standard stock solutions (500 mg L -1 ) of each compound (except carbendazim) were prepared by dissolving 25 mg (±0.01 mg) of each solid compound in 50 mL of acetone considering the purity of each solid standard. Standard stock solution of carbendazim was prepared in MeOH. Individual stock solutions and working standard solutions were stored at -20 and 4℃ in the dark, respectively.

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).