GC Analysis of Organophosphorus Pesticides (OP-Pest) in Cabbage, Onion, and Mushrooms on SLB-5ms after SPE using Supelclean™ ENVI-Carb™ II/PSA
Materials
analytical column
SPE tube or plate
Supelclean™ ENVI-Carb™ II/PSA SPE Tube
bed B 500 mg (Supelclean™ PSA SPE), bed A 500 mg (Supeclean™ ENVI-Carb-II SPE), volume 6 mL, pk of 30CONDITIONS
sample preparation
SPE (Solid Phase Extraction)
sample/matrix
10 g homogenized food sample (green onions, apples, Napa cabbage, button mushrooms)
SPE tube/cartridge
Supelclean ENVI-Carb II/PSA SPE Tube (54067-U)
condition
5 mL acetone:toluene (65:35)
sample addition
1 mL sample extract
elution
10 mL of acetone:toluene (65:35)
eluate post-treatment
Evaporate fraction to 0.5 mL then adjust volume to 1 mL with ethyl acetate for GC-NPD analysis
column
SLB-5ms, 30 m x 0.25 mm I.D., 0.25 μm (28471-U)
oven
110 °C (2 min), 2.5 °C/min to 205 °C, 10 °C/min to 310 °C (10 min)
inj. temp.
250 °C
detector
NPD, 310 °C
carrier gas
helium, 0.9 mL/min constant flow
injection
2 μL, splitless
liner
4 mm I.D. dual tapered
Description
Preparation Note
Sample pretreatment: To a 10 g sample of homogenized food (green onions, apples, Napa cabbage, button mushrooms) was added 10 mL acetonitrile and 4 g magnesium sulfate (that had been heated at 550 °C) and 1 g sodium chloride. After centrifugation, the supernatant was removed and mixed with 1 g magnesium sulfate and centrifuged. 5 mL of the supernatant was removed and evaporated to 1 mL for SPE loading.
Analysis Note
Organophosphorous pesticide use in agriculture is widespread due to the fact that they are more amenable to environmental degradation in comparison to organochlorine or organonitrogen compounds. There are a large number of pesticides in the organophosphorous group, and because of their potential health effects, they are of particular concern on produce imported from areas in which they are commonly used. This chromatogram illustrates the separation of 63 of these pesticides by GC on the SLB-5ms using nitrogen phosphorus detection (NPD).
Legal Information
ENVI-Carb is a trademark of Sigma-Aldrich Co. LLC
Supelclean is a trademark of Sigma-Aldrich Co. LLC