Carrots, root parsley, beetroot and potatoes are representatives of a group of products where, due to the characteristics of production and the contact of edible parts with the soil, there is a justified need to control pesticide residues.
The root system absorbs water and minerals from the soil solution, but under certain conditions, it can also absorb the residues of some pesticides present in the soil. The degree of their absorption and translocation within the plant depends, among other things, on the physico-chemical properties of the substance, the type of soil, environmental conditions, the plant species and its stage of development.
Plant protection products are used in different stages of cultivation, in accordance with the scope and conditions of their license. The level of residues in the product at harvest, among other factors, is influenced by the dose, time and method of application, number of treatments, observance of the pre-harvest interval, weather conditions, soil properties and the rate of decomposition of the given substance.
For this reason, root vegetables such as carrots, root parsley, beetroots, celery, and radishes, as well as potatoes as tuber crops, should be included in pesticide residue control programs. The extent and frequency of testing should be determined based on a risk analysis, taking into account product type, the history of crop protection product use, country of origin, legal requirements and customer requirements.
Identification of analytes and evaluation of compliance
The high sensitivity of modern analytical methods enables the detection of many chemical substances at very low concentrations.
However, the mere detection of an active substance, its metabolite or a product resulting from its decomposition or reaction in the tested sample does not automatically mean that the product does not comply with legal requirements. Conformity assessment requires the determination of residue levels and comparison of the results with the applicable maximum level, taking into account the applicable residue definition, product type and measurement uncertainty.
In the European Union, these issues are regulated by Regulation (EC) No 396/2005 of the European Parliament and of the Council on maximum residue levels of pesticides in or on food and feed of plant and animal origin, and in the Republic of Serbia by the Regulation on maximum permitted amounts of residues of plant protection agents in food and animal feed (Official Gazette RS 13/2026, 75/2026).
MRL (maximum residue level) is the highest allowed concentration of residues of plant protection agents in or on food and animal feed, determined in accordance with good agricultural practice and the lowest consumer exposure necessary to protect the most sensitive groups of consumers, and is expressed in mg/kg of the tested product.
Analytical Specificity of Root Vegetables and Classification of Tested Products
In the case of vegetables whose edible part develops in the soil, the assessment of the risk of pesticide residues should not be limited only to the treatment carried out immediately before harvest.
The residues present may be the result of the method of cultivation, the properties of the active substance and its persistence in the soil. The purpose of the raw material is also important: direct commercial distribution (fruits and vegetables), industrial processing or further use as an ingredient from which processed food is produced.
The correct classification of the tested product is of crucial importance. The term “root vegetables” is used in agricultural and industrial terminology, while regulations regarding maximum pesticide residue levels use a detailed product classification.
Interpretation of test reports in relation to applicable maximum residue levels (MRLs)
When an accredited laboratory detects a certain pesticide residue in a sample, when making a decision on compliance, it checks, among other things:
• which MRL applies for a given substance and product
• whether the determined level exceeds the applicable MRL, taking into account the measurement uncertainty and the appropriate decision rule
Detection of Multiple Active Substances (Multiple Residues) and risk assessment
Laboratory testing of one sample can determine the simultaneous presence of residues of several pesticides, for example, soil-applied herbicides and foliar-applied fungicides. However, the number of detected substances does not automatically mean that the product does not comply with legal requirements or that it poses a health risk.
The European Food Safety Authority (EFSA) indicates that the presence of several types of residues does not constitute non-compliance as long as the individual levels do not exceed the corresponding maximum residue levels (MRLs). Also, the determination of residues of multiple pesticides in individual batches of products may indicate the need for additional monitoring, taking into account the potential cumulative exposure of consumers.
Determination of maximum residue levels (MRL) and assessment of consumer exposure
The maximum allowed level of residues is not a value established arbitrarily. It is determined on the basis of residue data obtained during controlled field trials that reflect Good Agricultural Practice (GAP), while respecting consumer safety.
As part of its assessment, EFSA assesses acute and chronic dietary exposure of consumers to pesticide residues. For this purpose, it uses the PRIMo model, based on data on food consumption and other information relevant to different groups of consumers.
Exceeding the applicable maximum residue level (MRL) represents a non-compliance with the requirements related to the levels of pesticide residues and may indicate, among other things, improper use of the plant protection product, violation of the conditions of good agricultural practice or the presence of residues originating from another source. However, this does not automatically mean that there is an acute health risk. Health risk assessment requires a specific assessment of consumer exposure and comparison with an appropriate toxicological reference value, such as an acute reference dose (ARfD).
Legislative changes as a factor of operational risk
Regulations relating to maximum pesticide residue levels are not static. MRL values, residue definitions and the range of products covered by individual limits may change due to new scientific assessments, reviews of existing MRLs and regulatory decisions. EFSA conducts reviews of existing MRLs in accordance with Article 12 of Regulation (EC) No 396/2005, publishing reasoned opinions on individual substances. However, the final changes to the legally binding MDK are introduced by the European Commission through appropriate legal acts.
In practice, this means that the results of pesticide residue testings, carried out several months earlier, must always be compared with the legal status in force at the time the goods are placed on the market. For manufacturers, importers and distributors, this means that there is a need for continuous monitoring of regulatory changes, instead of conducting analyzes only occasionally, as needed.
Advanced instrumental analysis in the laboratory
The determination of trace levels of pesticide residues in complex plant matrices requires the application of appropriately validated test methods and efficient sample preparation procedures.
Sample preparation using the QuEChERS method is carried out in accordance with the SRPS EN 15662 standard, which enables efficient extraction of analytes from plant matrices with different water and sugar content.
The use of gas chromatography coupled with tandem mass spectrometry (GC-MS/MS) and liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) enables the identification and quantitative determination of a wide range of pesticide residues at low concentrations.
Pesticide residue monitoring in an integrated quality control system
Well-organized monitoring of product conformity involves more than occasional testing of the final product. In order to ensure proper control of the entire supply chain, it is important to include the following elements:
– origin of the raw material, country of origin and available information on the history of agrotechnical measures applied by the supplier
– seasonal factors and specifics of cultivation technology in a certain year
– selection of an appropriate set of analyzes adapted to the actual risk profile
Accredited testing of pesticide residues in SP Laboratorija
As an accredited testing laboratory, SP Laboratorija conducts professional analyzes of the presence of pesticides in fruit, vegetables and processed products, providing support to producers, importers and retail chains.
Contact us: https://splaboratorija.rs/kontakt/becej-srbija/
