Fast, high sensitivity analysis of chlorophenols and common odorants to assess water quality by HiSorb TD–GC–MS
Presented at ISC, Liverpool, UK 2024
Chlorophenols are an important class of volatile organic compounds (VOCs) to monitor in water. At low levels they can negatively affect human health, harm aquatic wildlife and impart antiseptic-like tastes or odours that consumers find unpleasant.
They are used as disinfectants, pesticides and in industry as intermediates. Pentachlorophenol (5CP) and, to a lesser extent, 2,3,4,5-tetrachlorophenol (4CP) are widely used as wood preservatives for outdoor fixtures such as telegraph poles, fence posts and garden furniture that can wash off and enter water streams. 5CP can break down in the environment, especially in the presence of microorganisms, losing chlorine atoms to give tetra- and trichlorophenols.
As a result, chlorophenols are regulated globally by the US Environmental Protection Agency (EPA), the Korean Ministry of Environment and the European Commission, with the EPA stipulating a limit of 1 μg/L for 5CP in drinking water. Standard methods for detecting chlorophenols including ISO 8615-2:1999 and US EPA method 604 specify liquid-liquid extraction with derivatization. These methods are manual, generate a lot of solvent waste and use harmful derivatising agents.
In addition to chlorophenols, many other odorants commonly affect drinking and environmental waters, including methoxypyrazines, halogenated anisoles and some terpenes, e.g., geosmin and 2-methylisoborneol, naturally produced by microorganisms in the water. These compounds have extremely low human odour threshold limits - in the region of 1 to 10 ng/L.
In this poster we demonstrate a faster and simpler solvent-free sample extraction method using HiSorb™ with thermal desorption (TD) analysis. Target chlorophenols and common odorants were analysed in a single GC run while achieving excellent sensitivity, detecting down to trace concentration levels as low as 2 ng/L. The method was also applied to five real-world samples to determine levels of odorants in different water sources.
