Pesticides multiples

sample/matrix

Pesticides at 10 ppb in 0.1M phosphate buffer, pH 7, with 25% NaCl, 9 mL in 10 mL screw cap vial

SPME fiber

60 μm Carbowax (PEG) (57354-U)

extraction

30 min. direct immersion with agitation using CombiPal autosampler

column

SLB-5ms, 30 m x 0.25 mm I.D., 0.5μm film

desorption process

2 min. at 250°C, splitless for 0.75 min. then opened

oven

60°C(1 min) to 150°C @ 25°C/min to 230°C @ 5°C/min to 310°C @ 18°C/min (3 min)

inj. temp.

Splitless/split with 0.75mm ID liner and Merlin Microseal

detector

ITMS m/z=60-450 @ 0.9 μsec per scan, transfer line 310°C

carrier gas

Helium, 1mL/min constant flow