This is the third post in our Method 5035 Series. Previous posts focused on the TCEQ Regulatory Update and the history and requirements of Method 5035A. Check back for our final post of the series which will cover sampling and analytical considerations and best practices.
In July 2015, the TCEQ Remediation Division provided technical guidance for implementing SW-846 Method 5035A for the sampling and analysis for volatile organic compounds (VOCs) in solid samples. Multiple options are presented in SW-846 Method 5035A and according to the guidance any of the procedures specified in Method 5035A for sample collection, preparation, and analysis can be used for volatile soil sample collection and analysis. These additional options include use of Encore™ sampling devices, collection of samples in deionized water, sodium bisulfate solution and/or methanol.
However, the TCEQ Remediation Division has made specific recommendations in the technical guidance that are presented below directly from Section 3.0 of the technical guidance.
- Collecting soils via a closed-system using an open-bore syringe and 40-milliliter (mL) volatile organic analysis (VOA) vials without preservatives as described in Method 5035A, Appendix A, sections A.7.0 and A.8.2.2.
NOTE: Samples collected in VOA vials can only be analyzed one time. Therefore, collect at least three separate vials at each sample location:
- one vial for low-level concentration analysis,
- one vial for low-level concentration reanalysis, if needed; and
- one vial in the event of high levels of VOCs requiring methanol extraction.
Collect an additional container (e.g., 40-mL vial or 4-ounce wide-mouth jar) for VOC screening and moisture determination.
- Wiping the threads of the vial clean prior to sealing the vial, then quickly sealing and chilling the vial and holding and shipping the vials at <6°C to the laboratory.
- Instructing the laboratory to analyze the sample within 48 hours from the time of collection or, to extend the hold time to 14 days, preserve the sample by freezing and storing the samples at <-7 °C.
- If the sample is preserved with methanol, i.e., the VOC concentration is known or suspected to be high, the volume of methanol used in samples with a significant moisture content (>10%) must be corrected for sample moisture content as described in Section 11.5 of Method 5035A and Section 11.10.5 of Method 8000C.
Environmental Standards recommends careful review of Method 5035A combined with training of field crews prior to sample collection events. The recommended procedures above have specific collection, storage, and holding time requirements with distinct advantages and disadvantages that must be considered.
If you have operations and site responsibility in Texas, beginning on January 1, 2016, solid samples for VOC analysis must be collected and prepared using the Method 5035A procedures.
Check back for our final blog post in our Method 5035 series: Method 5035 Sampling, Analytical Considerations & Best Practices.