Analytical Preparation for Chemical Testing in the Context of Updating Israel’s Drinking Water Regulations

Ludmila Groisman, National Public Health Laboratory, Ministry of Health, Tel Aviv, Israel (luda.groisman@phlta.health.gov.il)
E. Rabinovich, National Public Health Laboratory, Ministry Of Health, Tel Aviv, Israel
N. Tejman-Yarden, National Public Health Laboratory, Ministry Of Health, Tel Aviv, Israel

The Committee for Updating the Israeli Drinking Water Regulations has completed its work and formulated recommendations for updating the drinking water regulations. These recommendations are now in the final stages of discussion and approval. The upcoming regulations aim to expand the list of regulated organic pollutants. Under the new framework, additional chemicals will be added to the 97 chemical parameters currently monitored in the drinking water regulations. The expanded list will include 46 new compounds, as follows: 20 new pesticides, 20 PFAS compounds and 6 additional disinfection by-products from the haloacetic acid group.

According to the Ministry of Health’s requirements, laboratories that test drinking water as a part of regulatory monitoring must be accredited by the Ministry and perform analyses using the methods specified in Standard Methods for the Examination of Water and Wastewater and/or U.S. EPA methods for drinking water analysis. However, not all chemicals tested in Israeli drinking water are covered by these reference methods. For example, more than half of the new pesticides have no established reference analytical methods, nor have their sampling technologies been evaluated.

This situation necessitates the development of new analytical methods and sampling technologies, including the adaptation of sampling techniques to specific test methods to ensure the collection of representative water samples. It is therefore essential to implement updated quality assurance/quality control (QA/QC) requirements for both initial and ongoing method validation and to meet all criteria for producing reliable results. For instance, these requirements include the use of isotopically labeled analogues for each compound analyzed by LC–MS technologies, determination of the limit of quantitation (LOQ) using the spiking method, verification of LOQ on each analysis day, and compliance with LOQ thresholds defined by the regulator, among other criteria.

The following information will be covered in the oral presentation: a detailed list of newly regulated compounds expected in the future, recommended strategies for developing analytical methods and sampling technologies for these substances, as well as updated QA/QC requirements.