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Consumable

Soil gas sampling

Quantitative purge-and-trap with GC(–MS) is a common approach for the analysis of VOCs and SVOCs in soil, but it involves labour-intensive sample preparation and pre-screening analysis. Soil probes are a complementary approach to purge-and-trap for analysis of VOCs in soil vapour that overcomes many of these issues. Their use supports compliance with ASTM D7758.

Overview

Stainless-steel assemblies are inserted into the ground, allowing soil gas to be sampled in-situ onto a sorbent tube, either pumped or passively. 

Established VOC air monitoring technology has also been applied to the monitoring of contaminated land, but the frequently-used approach of canister sampling excludes many heavier organic pollutants. Sampling onto sorbent tubes, followed by thermal desorption analysis, allows a much wider volatility range to be addressed. Soil probe technology therefore has the potential to significantly speed up and reduce the cost of surveys of contaminated land.

Monitoring contaminated land and petrochemical pipelines are the primary applications of soil sampling, but other applications include:

  • Landfill/domestic waste sites.
  • Gasoline retail outlets and car service stations.
  • Active industrial sites.
  • Oil/gas pipeline monitors.

Benefits

  • Soil probes (especially when used with passive samplers) allow cost-effective, in-situ screening of large areas of land.
  • Probes can be placed along the length of fuel pipelines to provide early warnings of leaks.
  • Soil probes arranged in a grid pattern around an industrial site allow low-cost mapping of contaminated ground.
  • Different probe lengths support targeted contaminant depth analysis.