GC Analysis of Cocaine in Urine on a 100% Methyl Column after SPME using 100 μm PDMS Fiber

sample/matrix

0.5 mL urine (250 ng each analyte, 20 μL 2.5% NaF) in 1 mL vial

SPME fiber

polydimethylsiloxane, 100 μm (57300-U)

extraction

immersion, 30 min

desorption process

3 min, 240 °C

column

100% methyl polysiloxane, 30 m × 0.32 mm I.D., 0.25 μm (Supelco equivalent, Equity-1, 28055-U)

oven

120 °C to 280 °C at 10 °C/min

inj. temp.

splitless (splitter opened after 1 min), 240 °C

detector

NPD, 280 °C

carrier gas

helium, 3 mL/min