Development of Field Testing Kits for the detection of halogenated compounds in water: chloramines, THM, HAA and TFA

The Laboratory of Environmental Chemistry (LCE) is a Joint Research Unit (UMR 7376) under the supervision of Aix-Marseille University and the CNRS (National Institute of Chemistry). It is located on the St. Charles campus in Marseille, where it has its own building (Building 10), and maintains a branch on the Arbois campus (Aix-en-Provence) in close collaboration with the units of the Observatory of Universe Sciences (OSU Pythéas), with which it has established numerous ties

The LCE’s field of activity encompasses i) the determination of the kinetics and chemical and photochemical mechanisms of transformation and transfer of contaminants in air, water, and soil, as well as ii) the development of innovative analytical methods for the on-line and continuous analysis of contaminants in air and water.

The LCE is organized into two teams:

- Instrumentation and Atmospheric Reactivity (IRA): This team focuses on studying aerosol behavior in the troposphere and the consequences of its reactivity on the chemistry of atmospheric systems.

- Transfer, Reactivity, and Analysis of Micropollutants in the Environment (TRAME): The team’s activities aim to study the biophysical and chemical fate of contaminants, identify sources of environmental contamination, and develop the methodological and analytical tools necessary for monitoring these contaminants.

Position background:

The position is offered at the Environmental Chemistry Laboratory (LCE, Aix-Marseille University) within the framework of the VIGILANCE research project funded by the French National Research Agency (ANR, AAPG 2025 call). This single-team research project aims to develop innovative field testing kits (FTKs) for the detection of halogenated compounds in water, including chloramines, trihalomethanes (THMs), haloacetic acids (HAAs), and trifluoroacetic acid (TFA).

Inorganic chloramines consist of monochloramine (MCL), dichloramine (DCL), and trichloramine (TCL). MCL concentrations are regulated in some countries, while DCL and TCL are frequently suspected to be among the major causes of the characteristic “chlorine” odor in drinking water. TCL is also associated with respiratory irritation in indoor swimming pools.

Chlorinated and brominated THMs (e.g., chloroform) and HAAs (e.g., trichloroacetic acid) are, for the most part, carcinogenic compounds, and their concentrations in drinking water must remain below regulatory thresholds established by the European Union and the World Health Organization (WHO).

TFA is the smallest compound within the PFAS family and is often detected at concentrations 10 to 100 times higher than those of other PFAS compounds. Although TFA currently presents a relatively low risk to human health and the environment, its extreme persistence, combined with increasing emissions, raises concerns regarding a potentially irreversible accumulation in environmental compartments. A provisional health-based guidance value of 60 µg/L has been established, with a target reduction toward concentrations below 10 µg/L.

Responsabilities and objectives:

The analytical methods developed within the project will rely on two successive steps:
a) solid-phase extraction (SPE) for analyte preconcentration and purification and b) detection by absorbance or fluorescence measurements following reaction with analyte-specific reagents.

The successful candidate will continue the development of the chloramine detection method initiated during a Master's research internship. This method is based on a combination of SPE columns coupled with selective detection reagents for inorganic chloramines.

The THM and HAA detection methods will be developed through optimization of existing analytical approaches, including Fujiwara reactions using pyridine or pyridine derivatives or Reimer–Tiemann reactions using resorcinol, combined with a dedicated SPE step to be developed.

The TFA analytical kit will require the development of an entirely novel methodology, as no simple absorbance- or fluorescence-based detection methods are currently available. The method will be based on a derivatization reaction involving a chromogenic or fluorescent reagent, coupled with selective liquid–liquid extraction. An SPE step will subsequently be adapted according to the performance of the detection methodology, particularly to improve overall selectivity.

All developed methods will be validated through comparison with reference chromatographic techniques (GC–MS and LC–MS) and subsequently applied to a variety of real samples, including drinking water, swimming pool water, and natural waters.

• Master's degree (MSc), engineering degree, or equivalent (minimum five years of higher education) in analytical chemistry or a closely related field.
• Strong knowledge of : spectrophotometry; metrology and analytical quality assurance; general chemistry; analytical chemistry.
• Be familiar with reading and writing scientific articles ;
• Interest in the development and optimization of laboratory-based chemical analytical methods.
• Strong organizational skills, scientific rigor, autonomy, curiosity, and ability to work effectively within a research team.