Reevaluating the Holding Time & Preservation Requirements for Acrolein & Acrylonitrile in Water

Operational Issues Impacting the Environmental Laboratory Industry
Oral Presentation

Prepared by D. Friedman1, R. Burrows2, B. Meadows3, J. Morgan4, J. Paar5, A. Hanley6, T. Strock7
1 - American Council for Independent Laboratories (ACIL), 10817 Rippon Lodge Drive, Fairfax, VA, 22032-2931, United States
2 - Eurofins TestAmerica Laboratories, 4955 Yarrow Street, Arvada, CO, 80002, United States
3 - Babcock laboratories, , , United States
4 - Pace Laboratories, , , United States
5 - The NELAC Institute, , , United States
6 - US. Environmental Protection Agency/Office of Water, , , United States
7 - US Environmental Protection Agency/ORCR, , , United States

Contact Information: [email protected]; 703-389-3821


For a number of years, members of the laboratory community have been asking the Environmental Protection Agency (EPA) to modify the holding time and preservation requirements for acrolein and acrylonitrile in EPA Method 624. The industry has asked that: (a) the requirement to preserve samples at a pH of 4-5 be eliminated and instead make the preservation requirement identical to that for purgeable aromatic hydrocarbons, which preserves samples below pH 2, and (b) that the allowable maximum holding time be extended to 14 days.

In a letter sent to EPA on November 2010, the former Environmental Laboratory Advisory Board (ELAB) cited data from URS Corporation, demonstrated that acrolein and acrylonitrile were stable in both deionized water and groundwater whether the samples had not been preserved or had been preserved with HCl to pH 2. Samples were shown to be stable for, at least, 16 days. EPA has deemed the information received from ELAB/URS insufficient to justify the requested changes.

The Environmental Monitoring Coalition (EMC), was recently formed of organizations and individuals active in environmental monitoring. Members include: experts from commercial environmental testing laboratories, state laboratory associations, state regulatory agencies, other trade associations, academia, federal and state agencies, data users, and environmental monitoring vendors including consulting firms and laboratory assessment bodies.
The EMC focuses on developing consensus recommendations to federal and state agencies and stakeholder groups that will reflect the opinions and positions of its constituents on issues that include but are not limited to:
• Validating and implementing methods for sample collection and for biological, chemical, radiological, and toxicological analyses;
• Standards and guidance for developing scientifically rigorous, statistically sound, and representative environmental measurements;
• Encouraging the performance approach in environmental monitoring and regulatory programs;
• Employing a quality systems approach that ensures that environmental monitoring data are of known and documented quality; and
• Facilitating the operation and expansion of a national environmental laboratory accreditation program.
In addition, the EMC works with government to assist with method development and validation efforts.

Since EPA has not acted on the ELAB request due to a lack of sufficient data demonstrating the validity of the requested change, the EMC initiated a study to collect the additional data needed for EPA to justify the requested change. The objective of the study will be to demonstrate that acidification of samples to pH≤2 preserves the acrolein and acrylonitrile concentration in water samples as well as the current 40 CFR Part 136, and SW-846 acidification to pH 4.0 – 5.0 requirement. A secondary objective will be to confirm the efficacy of the current preservation and holding time guidance. It is the goal of the EMC that with this additional data, the EPA Offices of Water and of Resource Conservation and Recovery will adopt the requested preservation and holding time recommendations in their respective programs.

In the study:
1. Samples will be collected from six (6) sources representing matrices of interest in the Clean Water Act (CWA) and Resource Conservation and Recovery Act (RCRA) programs.

2. Samples will then be split into three three aliquots. One aliquot will be preserved with 1:1 HCl to pH ≤ 2.; one to a pH of 4.0 – 5.0; and one aliquot will be left unpreserved. Each aliquot will then be used to fill 40 mL VOA vials and the vials spiked with acrolein and acrylonitrile to a level of 100 ppb of each of the subject compounds.

3. Samples will be analyzed on on Days 0, 3, 7, 10 and 14 using EPA Method 624.1.

5. The results of the testing will be evaluated to determine the efficacy of the preservation approaches and the suitability of a 14 day holding time and submitted to EPA.

This presentation will review the study design, present the results of the testing, and outline next steps to be taken by the EMC.