Determination of Pesticide Residues in Red Wine by QuEChERS Extraction, Quick QuEChERS Cleanup and LC–MS-MS Detection

The Application Notebook

The Application Notebook, The Application Notebook-09-02-2012, Volume 0, Issue 0

UCT

Red wine is a challenging matrix that contains organic acids, sugars, phenols and pigments such as anthocyanins. This application note describes a simple, fast, novel and effective method to clean up red wine co-extractives.

Extraction Procedure

a) Add 10 mL red wine to 50 mL tube (RFV0050CT)

b) Add 10 mL acetonitrile, vortex 30 s

c) Add salts from Mylar pouch (ECQUUS2-MP)

d) Shake vigorously for 1 min

e) Centrifuge at 5000 rpm for 5 min

f) Supernatant is ready for cleanup

Quick QuEChERS Cleanup

a) Load 1 mL supernatant with disposable syringe

b) Push the supernatant slowly through the cartridge (ECPURMPSMC)

c) Collect 0.5 mL extract into 2 mL autosampler vial

d) Add triphenyl phosphate as internal standard

LC–MS-MS Instrumentation

LC: Thermo Accela 1250 pump

  • Column: SepaxHP-C18, 2.1 × 100 mm, 3 µm, 120 Å

  • Guard: Restek C18 2.1 × 20 mm, 3 µm

  • Column temperature: Ambient

  • Injection: 10 µL at 15° C

  • Mobile phase: A: 0.1% formic acid in water; B: 0.1% formic acid in methanol

  • Gradient: 0 min: 95% A; 1 min: 95%; 3 min: 50% A; 8 min: 5% A; 14 min: 5% A; 14.2 min: 95% A; 16 min: 95% A

  • Flow rate: 200 µL/min

MS-MS: Thermo TSQ Vantage

  • Ion source: Heated ESI positive, 350 ºC

  • Spray voltage: 3000 V

  • Sheath gas: N2 at 40 psi

  • Auxiliary gas: N2 at 10 psi

  • Collision gas: Ar at 1.5 mTorr

Results:

Recoveries ranged from 81.6 to 112.2% with RSD less than 10.8% achieved for red wine samples fortified with 10, 50 and 100 ng/mL pesticides.

Figure 1: Top: Quick QuEChERS cartridges before and after cleanup of 1 mL red wine extract; Bottom: Red wine extract before (left) and after (right) Quick QuEChERS cleanup.

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