Soil quality - Sampling - Part 201: Physical pretreatment in the field
1Key Takeaways
This document specifies methods for pretreating samples directly in the "field" immediately after sampling. The pretreatment methods in this document are limited to: sample fragmentation methods aimed at reducing sample size/volume; preparation of composite samples; and selection of specific components from the sampled…
2Expert Interpretation
This article provides an in-depth interpretation of the ISO 18400-201:2017 standard for on-site physical pretreatment of soil sampling, covering methods such as sample segmentation, composite sample preparation, and specific component screening. It is suitable for reference by professionals in the fields of environmental investigation and soil quality assessment.
Technical Framework of Field Pretreatment
| Method Type | Applicable Scenarios | Key Technical Requirements |
|---|---|---|
| Sample Splitting | Large Volume Sample Reduction | The original particle size needs to be maintained, using Taylor Sample Divider or Rotary Sample Divider |
| Composite Sample Preparation | Multi-point Mixed Sampling | The quality deviation of incremental samples needs to be controlled within ±10% |
| Selective Sampling | Extraction of Specific Particle Size Components | The proportion of rejected materials must be recorded, and the sieve aperture must be ≥ 3 times the maximum particle size. |
Key operating specifications
1. Manual crushing of large aggregates
When the moisture content of the sample permits, a flat-head shovel or sledgehammer should be used to gently crush the aggregates to the target particle size. The operation must be completed in a windproof and rainproof environment to avoid component loss.
2. Quartering Sampling Process
- Pile the sample into a cone and repeat mixing three times
- Flatten and divide using a cross metal divider
- Retain two diagonal portions, with mass deviation ≤10%
- Repeat until the target subsample size is obtained
Recommendations for Standard Implementation
Sampling Plan Integration:Pretreatment methods must be written into the sampling plan in advance, and change management procedures must be initiated when field conditions deviate.
Equipment Selection:Stainless steel tools are recommended, and all contact surfaces must be thoroughly cleaned between sample handling.
Quality Control:Verifying sample uniformity through replicate sampling is recommended, especially when dealing with highly heterogeneous contaminated soils.
Technology Evolution Background
This standard supplements laboratory pretreatment standards such as ISO 11464 and ISO 23909, and is developed to meet special on-site needs:
- Simplified sample splitting process
- On-site construction plan for composite samples
- Volatile component protection clause
Coordinated use with DIN 19747 can ensure the integrity of chemical-physical-biological test samples.