Standards Development

Scope

This standard describes multi-class analysis methods using mass spectrometry detection to analyse pesticides and metabolites in drinking water, groundwaters and surface waters.

This standard specifies methods based on gas phase (GC) or liquid phase (LC) chromatography, followed by simple (MS), tandem (MS-MS) or high-resolution (HR-MS) mass spectrometry detection. It proposes direct injection (ID) of the sample with the LC method and various extraction methods for the LC and GC methods:

- liquid/liquid extraction (L/L)

- solid/liquid extraction with an cartridge (off-line SPE)

- on-line solid/liquid extraction with a single-use cartridge or on a preconcentration column (on-line SPE)

The compounds analysable using this standard are given in Annex A. The protocols are applicable to other compounds which are not explicitly dealt with in this standard, provided that their applicability has been checked. Annex B gives a list of compounds the stability of which is insufficient to justify laboratory analysis (degradation or loss of the compounds as soon as the sample is transported). In the case of pre-treatment by liquid-liquid extraction, this standard applies to water containing less than 250 mg/L of suspended matter. Solid/liquid extraction methods and direct injection are considered to only apply to the dissolved fraction of the compounds in the samples.

Gas chromatography methods will be used as a priority for thermostable and volatile molecules, while the liquid chromatography methods are more suited to polar, non-volatile and thermolabile substances. The quantification limits range from one nanogram per litre to several tens of ng/L (0,001 microg/L to 0,05 microg/L) depending on the molecule and the protocol used, and are dependent on the analytical equipment employed.

This document does not describe the specific pesticide analysis methods devoted to a single class of compounds or using specific pre-treatment such as derivatization.

In the light of the open nature of the proposed protocols, the laboratory should characterize its methods by including accuracy tests, for example applying the complete protocol of standard NF T 90-210 or standard XP CEN/TS 16800.

Purpose

Water is a crucial resource, and its quality must be ensured. For this reason, a set of European directives has been implemented under the umbrella of the Water Framework Directive (WFD), which requires the monitoring and control of the occurrence and concentrations of potentially polluting substances in the aquatic environment.

According to the WFD and Directive 2013/39/EU [1], monitoring programs should generate high-quality data on the concentration of priority substances and other pollutants in the aquatic environment. Within the framework of the European directive on the quality of water intended for human consumption (2020/2184/EU), close monitoring of drinking water quality is planned; this monitoring also includes the active substances of pesticides and their metabolites in drinking water.

Existing standards for pesticide analysis are dedicated to specific families of pesticides; although relevant, they do not represent the entirety of laboratory practices. It is proposed here to have a 'multiresidues' standard allowing the measurement of a large number of compounds belonging to several chemical families, using mass spectrometry techniques.