A study to assess the viability of novel in-situ techniques for determining chloroform in drinking water in developing countries

Abstract

The aim of this study was to research appropriate methods for the in-situ analysis of chloroform and other disinfection by-products (DBPs) in drinking water and then assess the viability of these techniques by comparing them against the established methods. A literature search was undertaken using Web of Science and the various features contained within it to research a series of techniques in three distinct categories. These were βeta-cyclodextrin (βCD) techniques, colourimetry techniques and gas-chromatography (GC) techniques. Of the βCD techniques studied, the 2014 paper by Ncube et al showcased a novel method using an azo dye modified βeta-cyclodextrin epichlorohydrin polymer to measure chloroform concentration in drinking water (Ncube, Krause & Mamba, 2014). The limit of detection (LOD) obtained was lower than that of the World Health Organisation (WHO) guideline value for chloroform of 0.3 mg/L (WHO, 2008) but not lower than the U.S Environmental Protection Agency (USEPA) maximum acceptable limit for total trihalomethanes (TTHM) of 0.08 mg/L (USEPA, 2021). For the colourimetry techniques the method by Fattahi et al used a cotton pad soaked in reagents to quantify chloroform at LOD’s lower than any of the other in-situ techniques studied (Fattahi & Shariati-Rad, 2020). These methods were compared against GC techniques in particular the method by González-Hernández et al (2017) which was the most inexpensive method that was still fit for purpose. In conclusion the paper by Fattahi & Shariati-Rad (2020) represented an optimal method for the in-situ analysis of chloroform and was able to compete with more expensive GC methods.