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6.6 Appendix 
6.6.1 Reagents and solvents 
The reagents and solvents were of the highest purity available. The following solvents 
were used: acetone (Merck, SupraSolv®), dichloromethane, /7-hexane (Baker, Ultra resi- 
analyzed) methanol (Baker, Hplc-analyzed). Deionized water was obtained from an 
ultra-filtration system (Millipore milli-Q academic A10, 18.2 Milcm). 
All glassware was washed twice with acetone, dried, and then washed twice with n- 
hexane. After that the glassware was heated at 180°C for 5 h. 
6.6.2 GC-MS method for the determination of Chlorpyrifos, Endosulfan 
and Trifluralin 
All analyses were carried out with a Trace GC capillary gas chromatograph coupled to 
a Trace MS mass spectrometer (both Thermo Finnigan). Analyses were conducted with 
the following parameters: 
Column: 
Carrier gas: 
Oven temperature: 
Injector: 
Interface temperature: 
Detection mode: 
ZB-5 from Phenomenex (5 % Phenyl-, 95 % 
dimethylpolysiloxan) 30 m x 0.25 i. d. x 0.25 pm; 1 m 
precolumn ZB-5 
Helium 1.5 mL/min 
40 °C, 1 min isotherm; linear temperature gradient 
(5.5 °C/min to 320 °C; then 10 min isotherm) 
PTV splitless (Inlet temperature: 50 °C; split flow: 
30 ml/Min; splitless time: 1 Min; injection phases: 
injection: 40 kPa, 50 °C, 50 mL/Min , 0.01 Min; 
evaporation: 140 kPa, 14.5 °C/s, 60 °C, 0.5 Min; transfer: 
210 kPa, 14.5 °C/Min, 280 °C, 10 Min) 
280 °C 
NCI 
Reagent gas: 
Source temperature: 
Emission current: 
Dwell time per mass: 
Methane 
130 °C (NCI) 
150 pA 
50 ms