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Extraction of Pesticides From Pigmented Fruit or Vegetables
Using QuEChERS Methodology
(Part Number: 60105-216, 60105-218 and 60105-221)
Sample Preparation
Add 15g of homogenized and hydrated tomato product
(>80% moisture) to a centrifuge tube 60105-216
Add 15mL ACN including internal standard
Mix/vortex for 30 seconds
Centrifuge for 2 minutes at 3450 rcf
Draw 1 or 6mL of supernatant for clean-up
Clean-Up
For 1mL of supernatant, use product 60105-221
For 6mL of supernatant, use product 60105-218
Add supernatant to centrifuge tube and shake vigorously
for 1 minute
Centrifuge for 2 minutes at 3450 rcf
Analysis
GC/MS:
Transfer an aliquot of supernatant from step 2 to a
centrifuge tube
Add TPP solution and 1mL of toluene
Evaporate using nitrogen at 50°C to approximately
0.3 to 0.6mL
Bring to 1mL final volume with toluene
Inject 8µL on to GC/MS
LC/MS:
Transfer 0.25mL of supernatant from step 2 to an LC vial
Add TPP solution and 0.86mL of 6.7mM formic acid
Analyze by LC/MS
Determination of Quinolone Residues in Honey
Using 60mg 3mL HyperSep Retain-CX
(Part Number: 60107-303)
Sample Preparation
Add 5g of sample to a 50mL centrifuge tube
Make up Quinolone standard solution to a concentration
1µg/mL in 0.1mol/L sodium hydroxide solution
Quinolone Standards: Enrofloxacin (ENR), Ciprofloxacin
(CIP), Norfloxacin (NOR), Ofloxacin(OFL),
Flumequine(FLU), Oxolinic acid(OXO), Difloxacin
HCl (DIF), Sarafloxacin HCl(SAR), Sparfloxacin
(SPA), Danofloxacin (DAN), Fleroxcain (FLE),
Marbofloxacin (MAR), Enoxacin (ENO),
Orbifloxacin (ORB), Pipemidic acid (PIP), Pefloxacin
(PEF), Lomefloxacin (LOM), Cinoxacin (CIN),
Nalidixic acid (NAL))
Add 50µL internal standard solution to 5mL of 0.1mol/L
sodium hydroxide solution
Mix/vortex
Condition HyperSep Retain-CX Extraction Column
1 x 5mL CH
3
OH
1 X 3mL H
2
O
Apply Sample
Load sample at 1 to 2mL/minute
Wash Column
1 x 3mL H
2
O
1 x 3mL of CH
3
OH
Elute Quinolone
1 x 3mL of CH
3
OH containing 5% formic acid
Collect eluate at 1 to 2mL/minute and evaporate to dryness
Analysis
Inject 25µL on to LC/MS
Flow rate: 0.20mL/minute
Mobile phase: methanol + water containing 0.1% formic acid
Recommended HPLC Column
Part Number
Hypersil GOLD 3µm, 150 x 2.1mm
25003-152130
Food Safety
Applications