QuEChERS Method for Pesticide Residue Analysis

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QuEChERS significantly improves laboratory efficiency and throughput. This procedure requires only small quantities of solvent and is capable of generating recoveries of 70-120% with RSDs <5% for a wide range of compounds.

A process in two steps:

1. Extraction

  • Solvent extraction techniques are designed to achieve maximum yield of analytes from the base matrix.
  • Solvent selection is important to minimize co-extracting compounds.
  • Analytes are extracted from the matrix with acetonitrile and salts/buffers.

2. Cleanup

  • Sample cleanup is necessary to reduce interferences.
  • Interferences can damage analytical instrumentation and complicate analyte identification and quantification.
  • The use of PSA, C18, GCB (Graphitized Carbon Black) or Z-Sep sorbents allow removal of sugars, lipids, sterols, organic acids, proteins, carotenoids, chlorophyll and other pigments prior to a GC-MS/MS or LC-MS/MS analysis.
  1. Homogenize sample
  2. Transfer sample to 50mL tube
  3. Add ACN and internal standard and shake for 1 min
  4. Extraction: Add extraction salts and centrifuge (55227-U for EN15662:2008 and 55234-U for 2007.01 AOAC)
  5. Cleanup: Transfer supernatant to cleanup tube
  6. Shake and centrifuge
    a) LC-MS/MS Analysis: Dilute extract with mobile phase
    b) GC-MS analysis: Analyze directly or after solvent exchange

 

QuEChERS Selection Guide

Products for the Extraction Step

Description Quantity Cat. No.
Method EN15662 :2008 (12 mL centrifuge tubes)
Supel™ QuE Citrate (EN) Tube – 4 g MgSO4, 1 g NaCl, 0.5 g NaCitrate dibasic sesquihydrate,
1 g NaCitrate tribasic dihydrate
50 55227-U
Supel™ QuE Citrate/Sodium Bicarbonate (EN) Tube – 4 g MgSO4,
5 g NaBicarbonate, 1 g NaCl, 0.5 g NaCitrate dibasic
50 55237-U
Method AOAC 2007.01 (12 mL centrifuge tubes)
Supel™ QuE Acetate (AC) Tube – 6 g MgSO4,
1.5 g NaAcetate
50 55234-U
Non buffered extraction tubes (12 mL centrifuge tubes)
Supel™ QuE Non-Buffered Tube 1 – 4 g MgSO4, 1 g NaCl 50 55294-U
Supel™ QuE Non-Buffered Tube 2 – 6 g MgSO4, 1.5 g NaCl 50 55295-U

 

Products for Cleanup (QuEChERS) Step

Method – EN15662:2008

Matrices* Product Description Cat. No.
2 mL Tubes
Cat. No.
15 mL Tubes
Groups 1, 2 and 3 General fruits and vegetables lightly pigmented 150 mg Supelclean™ PSA,
900 mg MgSO4
55437-U
25 mg Supelclean™ PSA,
150 mg MgSO4
55172-U
Pigmented fruits and Vegetables Moderate levels of chlorophyll and carotenoids 150 mg Supelclean™ PSA,
15 mg Supelclean™ ENVI-Carb™,
900 mg MgSO4
55446-U
25 mg Supelclean™ PSA,
2,5 mg Supelclean™ ENVI-Carb™,
150 mg MgSO4
55147-U
Pigmented fruits and vegetables High levels of chlorophyll and carotenoids 150 mg Supelclean™ PSA,
45 mg Supelclean™ ENVI-Carb™,
900 mg MgSO4
55464-U
25 mg Supelclean™ PSA,
7,5 mg Supelclean™ ENVI-Carb™,
150 mg MgSO4
55176-U
Groups 4, 5 and 6 Pigmented fruits and vegetables with waxes/lipids High Lipid Content 150 mg Supelclean™ PSA,
150 mg Discovery® DSC-18,
900 mg MgSO4
55439-U
25 mg Supelclean™ PSA,
25 mg Discovery® DSC-18,
150 mg MgSO4
55173-U

 

Method – AOAC 2007.01

Matrices* Product Description Cat. No.
2 mL Tubes
Cat. No.
15 mL Tubes
Groups 1, 2 and 3 General fruits and vegetables lightly pigmented 400 mg Supelclean™ PSA,
1200 mg MgSO4
55466-U
50 mg Supelclean™ PSA,
150 mg MgSO4
55287-U
Pigmented fruits and Vegetables Moderate levels of chlorophyll and carotenoids 50 mg Supelclean™ PSA,
150 mg MgSO4,
50 mg ENVI-Carb™
on request
     
Pigmented fruits and vegetables High levels of chlorophyll and carotenoids 50 mg Supelclean™ PSA,
150 mg MgSO4,
50 mg Discovery® DSC-18,
50 mg ENVI-Carb™
55289-U
400 mg Supelclean™ PSA,
1200 mg MgSO4,
400 mg Discovery® DSC-18,
400 mg ENVI-Carb™
55474-U
Groups 4, 5 and 6 Pigmented fruits and vegetables with waxes/lipids High Lipid Content 50 mg Supelclean™ PSA,
150 mg MgSO4,
50 mg Discovery® DSC-18
55288-U
400 mg Supelclean™ PSA,
1200 mg MgSO4,
400 mg Discovery® DSC-18
55470-U

 

Specialty Products for Method EN15662 or AOAC 2007.01 – Alternatives

Matrices* Product Description Cat. No.
2 mL Tubes
Cat. No.
15 mL Tubes
Groups 4, 5 and 6 Fatty or pigmented matrix
With less than 15% fat
20 mg Z-Sep, 50 mg Discovery®
DSC-C18 (alternative)
55284-U
120 mg Z-Sep,
300 mg C18 (alternative)
55506-U
Hydrophobic analytes
in fatty matrices
75 mg Z-Sep (alternative) 55411-U
50 mg Z-Sep,
150 mg MgSO4 (alternative)
55417-U
500 mg Z-Sep (alternative) 55491-U
300 mg Z-Sep,
900 mg MgSO4 (alternative)
55503-U
Fatty matrices
With greater than 15% fat
75 mg Z-Sep+ (alternative) 55408-U
50 mg Z-Sep+,
150 mg MgSO4 (alternative)
55414-U
500 mg Z-Sep (alternative) 55486-U
300 mg Z-Sep+,
900 mg MgSO4 (alternative)
55511-U
Improved recovery of planar pesticides in green matrices Supel™ QuE Verde,
150 mg MgSO4,
10 mg ENVI™-Carb Y,
50 mg PSA, 60 mg Z-Sep+
55447-U
Supel™ QuE Verde,
1200 mg MgSO4,
80 mg ENVI™-Carb Y,
400 mg PSA,
480 mg Z-Sep+
55442-U