BS 10176 Taking Soil Samples for Determination of Volatile Organic Compounds (VOCs)

BS 10176 is intended to improve the reliability of soil sampling by introducing procedures which, if followed correctly, minimise loss of VOCs to atmosphere during and after sample collection.  ALS have developed approaches based on these requirements.

Two principal methods of collecting samples are specified within the standard:

• a small intact core sealed to prevent loss of VOCs is taken and sent to the laboratory;
• a small portion of soil taken with a coring device is immediately placed in a preservative (e.g. methanol) in a sealed vial to be sent to the laboratory.

When assessing the risk from VOCs, soil samples can be subject to changes as a result of physical, chemical or biological reactions that may take place between sampling and analysis, therefore precautions must be taken during sampling, transport and storage. 

Many of these techniques have been used by ALS laboratories throughout Europe, the US and Australia for over 20 years.  Our experience has enabled us to provide practical and pragmatic solutions based on the latest UK and international guidance. 

As early as the 1990s, research was published suggesting the practice of soil collection in bulk containers for VOCs provides significantly biased low results.  It is well recognised and now widely accepted that this method often results in 90% to 99% loss of VOCs prior to laboratory analysis (Urban et al. 1989, Illias and Jaegar 1993, Lewis et al 1994, Hewitt et al. 1995, Liikala et al. 1996).  Various processes were identified for these losses, primarily focusing on volatilisation and microbial degradation.  Susceptibility of various VOCs to these two loss mechanisms is both compound and matrix specific.  In general, compounds with higher vapour pressures are more susceptible to volatilisation.  Aerobically degradable compounds are more susceptible to biodegradation.  In addition, the formation of other compounds not originally present in the soil can occur.  Loss of VOCs leads to analytical results that are unrepresentative of field conditions.

ALS has carried out extensive trials to the determine limits of detection for VOCs using methanol preservation.  Whether soil samples are collected as intact cores or preserved using methanol, an extra container will still be required for analysis of moisture content.  Additional quality control samples will be needed for each set of soils submitted.

We offer the following sampling options:

• En Core® sampling equipment for collecting an intact core
• Easy Draw Syringe® equipment for methanol preservation
• Terra Core® sampling equipment for methanol preservation

BS 10176 will change the way samples are currently collected for determination of VOCs.  In the case of methanol preservation, the steps leading up to those associated with the analysis process are performed in the field, while the more traditional approach has previously been stages associated with sample preparation occur in a laboratory.

It highlights the importance of close liaison and cooperation with your laboratory.  We can provide detailed sampling guidance.  Our client services team can advise you on the specific requirements for individual projects. 

A recorded webinar is available at the following link:

https://attendee.gotowebinar.com/recording/5875920295717747975

References

BS 10175:2011+A2:2017 Investigation of potentially contaminated sites – Code of Practice

BS 10176:2020 Taking soil samples for determination of volatile organic compounds (VOCs) – Specification

BS ISO 18400-106 Soil Quality – Sampling – Part 106: Quality control and quality assurance

Hewitt, A. D., Chemical Preservation of Volatile Organic Compounds in Soil, 1995, Environ. Sci. Technol., 1995, 31, 67-70.

Hewitt, A. D., Storage and Preservation of Soil Samples for Volatile Compound Analysis, USA Cold Regions Research and Engineering Laboratory, Special Report 99-5, 1999.

Hewitt, A. D., Jenkins, T. F., Grant, C. L., Collection, Handling, and Storage: Keys to Improved Data Quality for Volatile Organic Compounds in Soil. Am. Environ. Lab, 1995, 7: 25-28.

Hewitt, A. D., Lukash, N. J. E., Sampling for In-Vial Analysis of Volatile Organic Compounds in Soil, Am. Environ. Lab, 1996, 7: 15-19.

Illias, A. M., Jeager, C., Evaluation of Sampling Techniques for the Analysis of Volatile and Total Recoverable Petroleum Hydrocarbons (TRPH) by IR, GC, and GC/MS Methods. In: Kostecki P. T., Calabrese E. J., Bonazountas M., Eds, Hydrocarbon Contaminated Soils, Vol 3, Chelsea, MI, Lewis Publishers, 1993, 3: 147-165.

Liikala, T. L., Olsen, K. B., Teel, S. S., Lanigan, D. C., Volatile Organic Compounds: Comparison of Two Sample Collection and Preservation Methods. Environ. Sci. Technol., 1996, 30: 3441-7.

Siegrist, R. L., Jenssen, P. D., Evaluation of Sampling Method Effects on Volatile Organic Compounds Measurements in Contaminated Soils,

Environ. Sci. Technol., 1990. 24: 1387-1392.

Urban, M. J., Smith, J. S., Schultz, E. K., Dickinson, R. K., Volatile Organic Analysis of a Soil Sediment or Waste Sample, Fifth Annual Waste Testing and Quality Assurance Symposium, U.S. Environmental Protection Agency, Washington, DC, 1989, II-87-II-101.

Contact US: For further information contact our Client Services Team on:

Tel: +44 (0)1244 528 777    •    Email: hawardencustomerservices@alsglobal.com

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