Analysis of Halogenated Disinfection By-Products and Chlorinated Solvents in Drinking Water by GC-Dual ECD

Drinking Water
Poster Presentation

Prepared by , D. Cardona1, C. Cojocariu1
1 - Occoquan Lab/Virginia Tech, 9408 Prince William St, Manassas, Virginia, 20110, United States
2 - Occoquan Lab, 9408 Prince William St, Manassas, VIRGINIA, 20110, United States


Contact Information: david.lee@thermofisher.com; 408-242-2996


ABSTRACT

Chlorination is a widely used disinfection method for drinking water treatment due to its simplicity, effectiveness and cost. However, besides its benefits this process can generate unwanted disinfection by-products, compounds which are stable and linked to adverse health effects. Hence, most countries across the world have set regulatory limits for many halogenated disinfection by-products and chlorinated solvents in drinking water supplies as these chemicals can have serious health effects if present above these recommended levels in drinking water. Traditionally, the analytical method of choice for the preparation, detection and quantification of such compounds is liquid-liquid extraction of water using an organic solvent, followed by analysis using gas chromatography (GC) coupled to electron capture detector (ECD). The identification of the analytes is then confirmed by running the extract again on a second column phase or by mass spectrometry. In this work, a cost effective, robust and sensitive analytical method was tested for the analysis of 17 disinfection by-products and chlorinated solvents in drinking water samples with simultaneous confirmation on a second column phase using dual ECD detection. Method performance parameters such as chromatographic resolution, linearity of response, repeatability, recovery and sensitivity were demonstrated. Compound linearity was obtained with coefficient of determination values ≥ 0.995 and residual values (as average calibration factors) %RSD < 11 for all analytes. Compounds sensitivity was assessed as both instrument detection limit (IDL) and method detection limit (MDL). Besides, quantification of disinfection by-products and chlorinated solvents in real drinking samples was demonstrated with analytes recoveries of 80-120 % and a %RSD of < 10 for n=7 replicates of spiked samples. The experiments performed demonstrate a simple, cost-effective yet robust and sensitive analytical method that can be used for the routine assessment of halogenated disinfection by-product and chlorinated solvents in drinking water samples.