Frequent Questions

VOC Method 524.2: The method allows either a 5-mL sample volume or a 25-mL sample volume. Would a 10-mL volume be an allowed modification?

A 10-mL sample volume should be acceptable since the method allows for a sample volume up to 25-mLs. However, auditors can be very literal in their interpretation of the methods. Section 11.1.1 of Method 524.2 states: “This method is designed for a 25-mL or 5-mL sample volume, but a smaller (5 mL) sample volume is recommended if the GC/MS system has adequate sensitivity to achieve the required method detection limits.”  Depending on how an auditor interprets it, this statement could imply that a nonstandard sample size (a 10-mL volume) wouldn’t be allowed. So, to avoid a potential finding in an audit, the lab needs to seek clarification with their accrediting/certifying agency.


Have more questions? Submit a request