Significance and Use

This practice provides a general procedure for the solvent extraction of volatile and semi-volatile organic compounds from a water matrix. Solvent extraction is used as the initial step in the solvent extraction of organic constituents for the purpose of quantifying extractable organic compounds.

Typical detection limits that can be achieved using micro-extraction techniques with gas chromatography (GC) with flame ionization detector (FID), electron capture detector (ECD), or with a mass spectrometer (GC/MS) range from milligrams per litre (mg/L) to nanograms per litre (ng/L). The detection limit, linear concentration range, and sensitivity of the test method for a specific organic compound will depend upon the sample clean-up, injection volume, solvent to sample ratio, solvent concentration methods used, and the determinative technique employed.

Micro-extraction has the advantage of speed, simple extraction devices, and the use of small amounts of sample and solvents.

Selectivity can be improved by the choice of solvent (usually hexane or pentane) or mixed solvents, extraction time and temperature, and ionic strength of the solution.

Extraction devices can vary from the sample container itself to commercial devices specifically designed for micro-extraction. See 7.1 and 7.2.

1. Scope

1.1 This practice covers standard procedures for extraction of volatile and semi-volatile organic compounds from water using small volumes of solvents.

1.2 The compounds of interest must have a greater solubility in the organic solvent than the water phase.

1.3 Not all of the solvents that can be used in micro extraction are addressed in this practice. The applicability of a solvent to extract the compound(s) of interest must be demonstrated before use.

1.4 This practice provides sample extracts suitable for any technique amenable to solvent injection such as gas chromatography or high performance liquid chromatography (HPLC).

1.5 The values stated in SI units are to be regarded as the standard.

1.6 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.

1.7 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. For specific hazard statements, see Section 9 .

2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.

ASTM Standards

D1129 Terminology Relating to Water

D1193 Specification for Reagent Water

D3370 Practices for Sampling Water from Closed Conduits

D3694 Practices for Preparation of Sample Containers and for Preservation of Organic Constituents

D3856 Guide for Management Systems in Laboratories Engaged in Analysis of Water

D3973 Test Method for Low-Molecular Weight Halogenated Hydrocarbons in Water

D4210 Practice for Intralaboratory Quality Control Procedures and a Discussion on Reporting Low-Level Data

D4448 Guide for Sampling Ground-Water Monitoring Wells

D5175 Test Method for Organohalide Pesticides and Polychlorinated Biphenyls in Water by Microextraction and Gas Chromatography

Keywords

extraction; microextraction; sample preparation; semivolatile; volatile; water; Chemical analysis--water applications; Electron-capture detectors (ECD); Extraction methods; Flame ionization detectors (FID); Inorganic compounds--water; Microextraction; Organic compounds--water; Pentane microextraction; Sample preparation--water applications; Semi-volatile organic/inorganic compounds; Solvent extraction; Volatile matter content--water; Volatile organic compounds (VOC)--water;

ICS Code

ICS Number Code 13.060.45 (Examination of water in general)

DOI: 10.1520/D5241-92R11

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ASTM D5241