Document ID: chunk:federal_register_of_legislation:F2013C00288:reg:4:p7
Version: federal_register_of_legislation:F2013C00288
Segment Type: reg
Provision Reference: reg 4 (pt 7/12)
Character Range: 756859–759897

4.2.4.4)
                                                                                                                                                                                                                8. If small analysis portions (<10 g) are required, or smaller sieve sizes, grind at least 10 g of the <2 mm fraction to pass through smaller mesh sieves (0.15, 0.5 or 1.0 mm sieve size for sample sizes of <1 g, <2 g and 29 g respectively).

4.3              Volatile analytes  sample collection and preparation
These guidelines generally do not include instructions for sample collection, with the exception of samples collected for volatile analytes, as the sampling method has a direct bearing on the analysis method and reliability of the results. The site assessor may request the laboratory to advise on relevant collection techniques or to supply appropriate equipment.

For samples requiring analysis of volatiles as well as non-volatiles and/or semi-volatiles, it is recommended that additional, separate samples are taken for the various types of analysis, to allow for volatile analysis to be completed and repeated if necessary on samples which have not been homogenised or otherwise inappropriately treated.

    4.3.1         Sample collection
Samples should be collected with minimal sample disturbance and handling to avoid evaporative losses, as detailed in AS 4482.2-1999. Ideally, sampling is carried out using a coring device; however if this is not available, an alternative device such as a trowel may be used. In all cases, the sample-taker should ensure that the sample remains intact and the container is filled as full as possible to ensure minimal headspace and void space and evaporation potential. In many cases, taking duplicate samples is recommended to allow sample re-analysis if required (e.g. if contaminant levels are over range).

Since volatiles are easily lost from the ground's surface, sampling soil for volatile analysis should not be carried out from the surface layer unless a very recent chemical spill is being investigated.

Where the sample container will be subsequently opened to obtain a sub-sample for analysis, the dimensions of the original sample core taken should be such as to leave a minimum of void space (headspace, and between core and container walls) in the vessel. Where the whole sample is to be purged or extracted without prior opening, this need not apply.

If soils are granular and easily sampled, place sample cores immediately into:
    * two or more pre-weighed 40 mL glass volatile organic analysis (VOA) vials with PTFE-lined pierceable silicone septum caps
or
    * one or more wide-mouth glass jars (usually 125 mL or 250 mL) with PTFE-lined lid (see Table 4-1, Chapter 4 in SW-846 revision 4, 2007), and sub-sample according to the procedures given below.
If soils are difficult to sample, (for example, highly compacted or hard clays), it is recommended that a minimum of three core samples be placed into pre-weighed 40 mL glass VOA vials