Standards Development

Scope

This document specifies the method of gas chromatographic determination of 5 chlorophenols (2- chlorophenol; 2,4-dichlorophenol; 2,4,6-trichlorophenol; 2,3,4,6-tetrachlorophenol; pentachlorophenol) in water samples.

NOTE 1 Other chlorophenols that is not specified in scope, it can be applied after confirming the validate.

This document describes a liquid/solid extraction method using immersive solid phase extraction samplers. After sampling, retained organic compounds are released by thermal desorption (TD) and automatically transferred to a gas chromatography-mass spectrometry (GC-MS) system for analysis.

This method is applicable to determination of chlorophenols in surface water, ground water and drinking water

Purpose

Chlorophenol (CPs) is an organic water pollution. It is an aromatic hydroxy compound (phenol) containing one to five chlorine atoms. A large amount of Chlorophenols is exposed to aquatic environments because CPs are used as raw materials to synthesize pharmaceutical products, pesticides, solvents, textile additives, and specialty chemicals. Moreover, CPs such as 2-chlorophenol (CP), 2,4-dichlorophenol(2,4-DCP), 2,4,6-trichlorophenol(2,4,6-TCP), 2,3,4,6-tetrachlorophenol (2,3,4,6-TeCP), and pentachlorophenol (PCP) are also generated from phenols during the treatment of tap water with chlorination.

Some of the CPs, especially, 2,4-DCP, 2,4,6-TrCP, and PCP with a relatively large molecular weight, have the potential for bioaccumulation, aquatic toxicity, and resistance to degradation in aquatic environments and have also been recognized as endocrine disruptors. These compounds are also recognized as priority pollutants of aquatic environments in the USA (US EPA, 2014). Especially, the toxicity of PCP is indicated by the very low maximum contaminants level (1 ng/ml) and maximum contaminant level goal (0 ng/ml) set for drinking water in the USA, and by a Fresh Water Guideline of 0,5 ng/ml set by Canada for the protection of aquatic life. In South Korea CPs have been detected in river waters ranging of 2,01 to 91,1 ng/l. Therefore, it was necessary low detection limit analytical method for the measurement of chlorophenols.

The existing ISO standard method (ISO 8615-2:1999) present liquid/liquid extraction method as a sample preparation process. It contained several complex steps such as liquid extraction, phase separation and concentration etc. So, process is hard, complex, and spent time and labor. Additionally, the use of organic solvents such as dichloromethane has a harmful effect on the environment and the human body.

The proposed method specifies an optimized analytical procedure that ensures rapid, accurate, and simple analytical method for the determination of trace amounts of chlorinated phenols such as chlorophenol, 2,4-DCP, 2,4,6-TrCP, 2,3,4,6-TeCP, and PCP in water. And it is differing from existing ISO standard methods for Chlorophenols analysis in the following ways.

a) A novel sample preparation method, the Liquid/Solid extraction method, is used for CPs extraction from water. It can provide simple and rapid sample preparation process.

b) By using Thermal Desorption (TD) and Gas Chromatography Mass Spectrometry (GC-MS), sample desorption and injection process are performed automatically. This reduces human error, thus providing more accurate and precise analysis results