(71e) A Visible Colorimetric Sensor Based on Hydrophobic Syndiotactic Polypropylene Fiber Mats for the Determination of Trihalomethanes in Treated Drinking Water

Water is considered by many to be the most imperative resource on the planet. Despite its essentialness for life, water frequently undergoes pollution from many human processes, most notably industrial runoff. As a result, hazardous chemicals can be found in water sources, and in some cases, even drinking water. One specific class of carcinogenic chemicals of interest are trihalomethanes (THMs), which occur as a byproduct of water disinfection via chlorination, where natural organic matter reacts with halogens to form these toxic chemicals. The US Environmental Protection Agency (USEPA) limits the total concentration of total-THMs in drinking water to 80 ppb. Here, a colorimetric polymer fiber-based sensor was used for the detection of THMs down to 8 ppb. The sensor utilizes the Fujiwara reaction where THMs react with pyridine, which under basic conditions forms red chromophores whose intensity can be measured using image analysis software. The sensor operates by using a two-fold preconcentration technique consisting of simple thermodynamic separation and a hydrophobic syndiotactic polypropylene (sPP) mat to prevent the diffusion of evaporated water through the fibers, as water is detrimental to the Fujiwara reaction. This technique is inexpensive and more rapid than typical THM detection methods currently used to regulate the THMs in water supplies and can be performed on site. As this method is improved, it will be able to be used to ensure that water is potable and safe for drinking.