BS ISO 11464 pdf download – Soil quality ——Pretreatment of samples for physico-chemical analysis

BS ISO 11464 pdf download – Soil quality ——Pretreatment of samples for physico-chemical analysis.
The pretreatment procedures descnbed in this International Standard are not applicable if they affect the results of the determinations to be made. This International Standard is also not applicable to samples wtien volatile compounds are measured. In general. International Standards br analytical methods will state when it is necessary to adopt other procedures
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies For undated references, the latest edition of the referenced document (Wickidlng any amendments) applies.
ISO 565, Test sieves — Metal wire doth. perforated metal plate and electroformed sheet — Nominal sizes of openings
ISO 10381-8. Soil quality — Sampling — Part 8: Guidance on sampling of stockpiles
ISO 16720, Soil quality — Pretreatment of samples by freeze-drying br subsequent analysis
3 Phncpe
Sod samples are dried in air, or in an oven at temperature not exceeding , or freeze-dried (see 5.3). If necessary, the soil sample is crushed while still damp and friable, and again after drying (see 5.4). The soil is sieved and the fraction smaller than 2mm is divided into portions mechanically, or by hand, to enable
40 C
representative subsampling for analysis (see 5.5). If small subsamples (< 2 g) are required for analysis. the size of the particles of the fraction smaller than 2 mm is further decreased (see 5.6). The necessary procedures are given in the flow diagram in Figure 1 A drying temperature of 40 - C in an oven is preferable to air drying at room temperature because the increased speed of the drying limits changes due to microbial activity. It should be noted that every type of pretreatment will have an influence on several soil properties. The sieve aperture size of 2 mm is generally used. However, before the pretreatment is started, it should be cheded it any of the analytical methods to be applied later require other sieve sizes. NOTE Storing sod samples, including samples that ale as received, air dried. refrigerated or stored in the absence of light. for a long time may bsve an iriltu.nce on a number of sol parameters, especially solubililies of both inorganic and organic fracbw. See Reference 111. Special measures should usually be taken for samples from contaminated soils. it is important to avoid contact with the skin and special provisions should be taken when drying such samples (air discharge, ventilation, etc.). 5,4.2 Crushing If a 2 mm sieve has been used to facilitate removal of extraneous matter, any large dried particles remaining on the 2 mm sieve should be crushed (using suitable apparatus) to smaller than 2 mm. The apparatus used should be adjusted so that army crushing of the large particles is minimized to enable crushed particles to pass through the 2 mm sieve If a 2 mm sieve has not been used to facilitate removal of extraneous matter, then the dried sample should be sieved through a 2 mm sieve Any large dried particles remaining on the 2 mm sieve should be crushed (using suitable apparatus) to smaller than 2 mm, The apparatus used shall be adjusted in such a way that complete crushing of particles larger than 2 rvwn before drying is minimized. The whole sample passing through the 2 mm sieve should be weighed and well mixed. If the fraction of aggregates larger than 2 mm is low, it may be more efficient to sieve out particles smaller than 2mm prior to crushing. In special cases, the entire sample may be crushed Fractions may be recombined after crushing uslig a mechanical mixer (4.6). 5.5 Subsampling 5.5,1 General Subsampling is necessary when the sample cannot be stored (laboratory sample and archive sample) or used (test sample) completely, because of its size. For the preparation of a laboratory sample, divide the dried. crushed and sieved sample (now < 2 mm) into representative portions of 2009 to 3009 according to 5.5.2 or 5.5.3. For the preparation of a test sample, split up the laboratory sample mto representative portions until the required sizes of samples are obtained. Avoid the production of dust as much as possIe. In the case of larger sample masses. subsampleng methods according to ISO 10381-8 shall be used to reduce the initial sample size. It may be necessary to mu the material (5.6) between subsarnpling stages, to ensure homogeneity as the mass of the subsample is decreased. The procedures described in 5.5.2 and 5.5.3 may be used to produce subsamples/test portions of the materials srnaler than 2 mm, and not smaller than 2 g in mass.