Nitrogen-containing herbicides extracted from water

sample/matrix

4 mL (water + 100ng/mL each analyte 1g/mL NaCl), pH 2, in 4.6 mL vial

SPME fiber

polyacrylate, 85 μm (57304)

extraction

immersion, ambient temp., 50 min (constant stirring)

desorption process

5 min, 230 °C

column

5% phenyl polysiloxane, 30 m × 0.25 mm I.D., 0.25 μm (Supelco equivalent, SLB-5ms, 28471-U)

oven

40 °C (5 min) to 100 °C at 30 °C/min, to 275 °C at 5 °C/min

inj. temp.

splitless, 230 °C

detector

MS (Ion Trap Manifold: 250°C; scan range m/z=45-400 at 0.6 sec/scan)

carrier gas

helium, 40 cm/sec, set at 40 °C