Standard Guide for Field Preservation of Ground Water Samples

Importancia y uso:

4.1 Ground water samples are subject to chemical, physical, and biological change relative to in- situ conditions at the ground surfaces as a result of exposure to ambient conditions during sample collection (for example, pressure, temperature, ultraviolet radiation, atmospheric oxygen, and contaminants) (1) (2).6 Physical and chemical preservation of samples minimize further changes in sample chemistry that can occur from the moment the ground water sample is retrieved, to the time it is removed from the sample container for extraction or analysis, or both. Measures also should be taken to preserve the physical integrity of the sample container.

4.2 The need for sample preservation for specific analytes should be defined prior to the sampling event and documented in the site-specific sampling and analysis plan in accordance with Guide D5903. The decision to preserve a sample should be made on a parameter-specific basis as defined by individual analytical methods.

4.3 This guide includes examples from government documents in the United States. When work is in other countries or regions, the local governing or regulating agencies should be consulted.

Note 1: The quality of the result produced by this standard is dependent on the competence of the personnel performing it, and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing/sampling/inspection/etc. Users of this standard are cautioned that compliance with Practice D3740 does not in itself assure reliable results. Reliable results depend on many factors; Practice D3740 provides a means of evaluating some of those factors.

Subcomité:

D18.21

Referida por:

D6699-24, D4448-01R19, D7069-24, D6771-21, D6001_D6001M-20, D7929-20, D7100-11R20

Volúmen:

04.09

Número ICS:

13.060.10 (Water of natural resources)

Palabras clave:

chemical preservation; ground water sampling; holding time; physical preservation; preservative; sample preservation; temperature blank;