The EPA’s SW-846 Lab Audit Checklist PCB

The SW-846 Lab Audit Checklist PCB contains both general data validation guidance and technique-specific documents to be used when reviewing chemical analytical data generated for DoD projects using SW-846 methods. It should be utilized when reviewing this type of chemical analytical data generated.

This document serves as guidance for identifying essential contractual validation requirements when creating project-specific QAPPs.

1. Review the Methods

In general, the Agency encourages laboratory personnel to employ the most recent version of any analytical method; however, they do not place restrictions or preclude earlier versions when applicable and not required by RCRA’s hazardous waste regulations or existing permits or consent decrees.

Consistency being of paramount importance, some minor adjustments were made to the method text in order to achieve greater uniformity. For instance, the name of analyte for re-quantification in method blanks and instrument QC samples has been modified from bis(2-chloroisopropyl) ether to bis(2-chloro-1-methylethyl) ether for greater consistency.

Additionally, guidance for LLOQ check samples has been revised to indicate that they should be prepared and analyzed using similar procedures to those utilized when handling environmental samples and other QC samples. Furthermore, recommendations have been added regarding including predictions of LLOQ concentration levels of analytes in requantification calculations for sample, instrument QC and batch QC samples.

2. Review the Procedures

An important element of any laboratory audit is examining the procedures employed for sample handling, storage and analysis. Documented procedures should be updated frequently while any problems should be identified and rectified immediately – to ensure that data produced by the lab remains valid and trustworthy.

One important step for laboratory analysis is conducting matrix spike duplicates. This allows laboratories to ensure their method is functioning as intended and identify any possible matrix interferences that might exist.

Review of Chain of Custody and Field Quality Control Records is another essential procedure, and should be conducted on a regular basis by the Quality Assurance (QA) department. In addition, laboratory case narratives or any other reports prepared should also be thoroughly assessed to detect issues that require further review; as part of this procedure, the Quality Assurance Director must prepare an additional report outlining such areas requiring attention.

3. Review the Analytical Data

Analytical data used for quality control and verification comes from various sources, such as sample, instrument QC and preparatory batch QC samples. Analyzing these samples identifies components of uncertainty for each test performed in the lab, with this knowledge then used to create confidence intervals around test results reported with each result report.

These confidence intervals are determined using the chromatograms of internal standards and blank spike duplicates (intra-laboratory split samples that contain equal concentrations of an analyte that undergo identical analytical procedures), in addition to tracking retention times of matrix spike duplicates versus their respective continuing calibration standards as an additional verification measure for internal standard reagent consistency.

Final Update V of SW-846 brings revisions to Chapters One through Five that aim to increase clarity in documentation while giving more flexibility for applying method specific acceptance criteria.

4. Review the Results

The Environmental Protection Agency has issued an updated methods compendium for environmental laboratories conducting hazardous waste analysis under RCRA, including revised method tables and an amended version of Method 9014 which analyzes volatile organic compounds in solid and liquid waste samples by gas chromatography/mass spectrometry.

The Agency has also implemented changes that include replacing “method detection limit” (MDL) with lower limit of quantitation (LLOQ), revising Chapters One through Five of SW-846 accordingly and including updates from Ecological Laboratory Advisory Board (ELAB) into Chapter Two.

ELAB recommendations were adapted from National Functional Guidelines, tailored specifically for SW-846 methods and are not comprehensive for all methods. Re-quantification of target analyte detects for instrument QC samples, matrix spike duplicates and preparatory batch QC samples using raw instrument response data and reported calibration factors should also take place during these calculations; calculations must include variables like dilution factors, prep factors and percent moisture that could alter measurements.