Transcript PowerPoint-presentation

Multi-residue Methods used for
Pesticides Residues Analysis of Fruits
and Vegetables in Sweden
Arne Andersson
National Food Administration
Sweden
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Analytical method
• A multi-residue method (M001/101) using ethyl acetate
extraction and GPC clean-up was the main method
during 1989-2003
• Determination of residues was done using GC (ITD,
ECD, FPD, NPD) and HPLC
•Scope: about 200 pesticides and metabolites in one
single analysis
•For acidic crops, NaOH was added and a new
extraction was carried out (M002/102)
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Determination by LC-MS/MS and GC equipped
with conventional detectors
• In 2004 the HPLC determination was replaced by LC-MS/MS
• No GPC clean-up was needed
• Sensitive and selective provides quantification and confirmation
at the same time
• LOQ: 10 ppb (0.01 mg/kg) for most pesticides
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The new extraction procedure for all crops,
used from 1 January 2005
• Ethyl acetate and addition of 15 g NaHCO3, to all crops. This
increased the pH to 6-8 in acidic fruits and vegetables
• By this small change two old multi-methods could be
substituted by one new method (M200)
• The determination is carried out by LC-MS/MS, GC-ITD and
GC-ECD
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Present multi method for fruit and
vegetables
Extraction with ethyl acetate
NaHC03 and Na2S04
Filtration
Determination
GC (ITD, ECD)
LC-MS/MS
about 180 analytes about 120 analytes
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LC-MS/MS method
75 g sample + 200 ml ethyl acetate
+ 15 g NaHC03 + Na2S04
100 ml aliquote => 1 ml
adjust to 5 ml in ethyl acetate/cyclohexane (1+1)
7,5g sample/ml
500 µl EtAc/C-hexane extract =>
1500 µl in MeOH
2,5g sample/ml
LC-MS/MS
Q-Trap API 4000
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Benefits of using LC-MS/MS determination
• No GPC clean-up is needed
• Selective, provides quantification and confirmation at the same
time
• Better reproducibility for polar pesticides compared with GC
• LOQ: 10 ppb (0.01 mg/kg) for most pesticides
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Change to GC-MS/MS determination
The goal is to change from using GC –ITD and
GC-ECD to GC-MS/MS by 1 July 2006
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Improved multi method for fruit and
vegetables by 1 July 2006
Extraction with ethyl acetate
NaHC03 and Na2SO4
Filtration
Determination
GC-MS/MS
LC-MS/MS
about 110 analytes about 190 analytes
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GC method for dithiocarbamates
50g sample
150 ml tin chloride/HCl
25 ml isooctane
water bath 80°C, 60min
GC-FPD(S)
LOQ 0,025 mg/kg
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New multi method for cereals
Sample and water
Extraction with acetonitrile
NaCl and MgSO4
Filtration
Determination
LC-MS/MS
about 80 analytes
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EU Analytical Quality Control Guidelines
The revised version: SANCO/10232/2006, 24 March 2006
“Quality Control Procedures for Pesticide Residues Analysis”
Major updates:
• Confirmation using LC-MS/MS and GC-MS/MS
• Uncertainty and enforcement
http://europa.eu.int/comm/food/plant/resources/qualcontrol_en.pdf
Organizer: Tuija Pihlström, National Food Administration, Sweden
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EU Proficiency Test 7, 2005
List with 62 pesticides
16 of the pesticides were applied to a sample of grapes
125 labs in 27 countries participated
Satisfactory results (Z-scores <2):
79 – 96% for the individual pesticides present
Organizer: Amadeo Fernández-Alba, University of Almeria, Spain
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Homepage: www.slv.se
Thanks for your attention
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