Prioritisation for pesticide residue analysis: a practical guide

Ensure an effective and efficient approach to pesticide residue analysis by identifying and targeting the most appropriate samples.

Pesticides are used to help protect crops from pests and diseases. Legislation requires that their use is appropriately controlled and specifies Maximum Residue Levels (MRLs) that must not be exceeded. The level of pesticide residues in food raw materials is a measurable standard which indicates that pesticides have been correctly used in crop production. But while residue analysis is essential for companies wishing to assure themselves that their products have been produced in accordance with best practice and conform with legislation, it is used to greatest effect when targeted at the samples most likely to contain residues.

This publication therefore provides a standardised, formal system for food companies and analysts to prioritise residue analysis. Created after extensive consultation with industry practitioners and taking a practical stance, it provides a standardised approach for companies to prioritise the pesticides and circumstances at which analysis should be targeted. It takes account of factors such as the origin of the raw material, the supply route and the pesticide/crop combination.

The approach advocated is backed up with a worked example. Both the example and a template spreadsheet are supplied on disk (Microsoft Excel format) to facilitate adoption of the approach.

Pesticide residue monitoring - why is it necessary?

Current monitoring activity

• European monitoring
• UK government monitoring
• Company monitoring

CCFRA prioritisation method

• Background
• Principles
• Selection of factors
• Weighting of factors
• Awarding scores
• Summing scores
• Ranking scores
• Recording data
• Residue analysis data

Prioritisation case study

• Information about suppliers
• Information about raw materials
• Information about crops/residues
• Demonstration study

User guide for the spreadsheet

References

Spreadsheet

The spreadsheet encourages the collection and input of data in a structured way. It uses the raw data entered by the user to compute scores for all relevant samples and then ranks the samples on this basis. A step-wise procedure to using the spreadsheet is described in the guide. This will help the user appreciate how the spreadsheet works before tackling their own prioritisation exercise.

The spreadsheet requires input of information on:

• Nature of the raw materials
• Source of the raw materials (i.e. supplier information)
• Assessment of potential crop/pesticide combinations

Using this information, and weightings provided by the user, the spreadsheet calculates a specific score for each sample and ranks the samples accordingly.

Click here to view screenshots of the spreadsheet.

One free copy of the spreadsheet is provided with each copy of the guide. Its use requires a PC with Excel 97 and assumes proficiency with this package. The spreadsheet cannot be provided in any other format or package. The disk is provided to help readers to make quicker use of the prioritisation system but CCFRA does not undertake to provide support in the use of the spreadsheet or Excel. Both the spreadsheet and the guide are protected by copyright law.