Frequently Asked Questions about the DoD Quality Systems Manual for Environmental Laboratories

Frequently Asked Questions about the DoD Quality Systems Manual for Environmental Laboratories (Version 3)

Question 1: Please provide additional information on the application of the “Q” flag as it applies to failure to meet the LCS criteria.

EDQW Response: A Q flag, or note indicating criteria were not met, is to be included in the LCS report. A Q flag is to be applied to each sample result affected by the QC failure.

Question 2: Please clarify the requirement that test Method/SOP shall be reviewed for accuracy and adequacy at least annually.

EDQW Response: All documentation of methods (e.g. method and QA SOPs) must be reviewed (not revised unless appropriate) on at least an annual basis. Laboratories seeking compliance with the DoD QSM may want to consider a less cumbersome process for accomplishing annual review (e.g. annual review conducted by analyst) if the annual requirement seems overly burdensome due to internal laboratory review policies and procedures.

Question 3: If thermometers are received with traceable certificates, are they still required to be checked when received?

EDQW Response: Yes, this is a requirement of ISO 17025, upon which the NELAC Standard and DoD QSM are based. (ISO 17025 section 5.5.2) “Before being placed into service, equipment (including that used for sampling) shall be calibrated or checked to establish that it meets the laboratory’s specification requirements and complies with the relevant standard specifications. It shall be checked and/or calibrated before use.”

Question 4: Does the QSM Version 3 require the calibration of volumetric Class A glassware on an annual basis?

EDQW Response: No, the requirement for calibrating Class A volumetric glassware has been removed from Version 3 of the QSM.

Question 5: What are the requirements for documenting manual integrations for initial and continuing calibration (Box #50 and #57, Sections 5.5.2.2.1 and 5.5.10)?

EDQW Response: The data reviewer or user must be to be able to completely reconstruct chronological events leading to the final manually integrated chromatograms. Many software packages for audit trails do not allow full reconstruction and capture of “before” chromatograms. In those cases “before” chromatograms must be provided along with other information specified in DoD Box 50.

Question 6: When using methods that employ second column confirmation, which value should the laboratory report (Table B-2)?

EDQW Response: Table B-2 of the QSM states “Report the higher of two confirmed results unless overlapping peaks are causing erroneously high results, then report the unaffected result and document in the case narrative.” Therefore, unless directed otherwise by project documentation, the higher result is to be reported for each analyte (as is specified in the QSM), along with QC appropriate to support the result (whichever column generated it).

For methods for which confirmatory column analyses often do not achieve full resolution of all target analyte peaks (i.e. 8330), reporting the result from primary column (whether higher or lower) is preferred when co-elution actually occurs. In these cases, special care needs to be taken to ensure that an analyte has been qualitatively confirmed before it is reported. In cases where co-elution causes the 40% RPD criteria to be exceeded, the result from the primary column should be reported as estimated.

Question 7: Does the QSM allow updating the retention times after performing column maintenance (Table B3)?

QC Check

Minimum Frequency

Acceptance Criteria

Corrective Action

Flagging Criteria

Comments

Retention time window position establishment for each analyte and surrogate

Once per ICAL

Position shall be set using the midpoint standard of the initial calibration curve.

Evaluation of relative retention times (RRT)

With each sample

RRT of each target analyte in each calibration standard within +/- 0.06 RRT units.

Correct problem, then rerun ICAL.

Flagging criteria is not appropriate.

“If the retention time of any internal standard changes by more than 30 seconds from that in the mid-point standard level of the most recent initial calibration sequence, then the chromatographic system must be inspected for malfunctions and corrections must be made, as required. When corrections are made, reanalysis of samples analyzed while the system was malfunctioning is required.”

As required by Table B3, retention time windows shall be established using the initial calibration curve. However, it is not the intent of the QSM to prevent the laboratory from updating the retention times based on the CCV to account for minor performance fluctuations or after routine system maintenance (such as column clipping). With each sample, the RRT shall be compared to the most recently updated RRT. If the RRT has changed by more than ±0.06 RRT units since the last update, this indicates a significant change in system performance and the laboratory must take appropriate corrective actions as required by section 7.4.6 of the method and rerun the ICAL to reestablish the retention times, as required by Table B3 of the QSM.

Question 8: When performing analysis using ICP and ICP-MS, what is the appropriate action when a sample value is greater than the highest calibration standard but within the linear dynamic range?

EDQW Response: QSM Box #53 states, “When sample concentrations exceed the upper limit of the calibration curve, samples shall be diluted and reanalyzed (if possible) to bring them within the calibration curve. When sample concentrations exceed the upper limit of the calibration curve or fall below the lower limit of the calibration curve, the resulting data shall be qualified as having estimated values and shall be flagged.”

If results for a sample exceed the highest calibration standard then the sample must be diluted or the laboratory may elect to verify the instrumental response to + 10% by analyzing a standard with the same calibration that is within the defined linear “dynamic” range, but has a higher concentration than the sample.

The DoD does allow non-target analytes to be quantified when they fall outside the calibration range but inside in the linear “dynamic” range without sample dilution.

Question 9: At what frequency must all types of volumetric pipettes be checked for accuracy?

EDQW Response: Boxes 46 and 48 of Section 5.5.2.1, DoD QSM Version 3 require that "mechanical pipettes be checked for accuracy on at least a quarterly use basis." This requirement applies to both digital and Eppendorf® style pipettes.

EDQW Response: Exclusion of initial calibration points without technical justification is not allowed.” Therefore, any calibration points may be excluded with technical justification if the minimum number of standards required by the method for calibration is maintained and these points are contiguous. Exclusion of calibration points to achieve QC criteria does not constitute a technical justification. Note, during project-specific data review technical justification may be determined inappropriate, resulting in flagging of associated data points.

EDQW Response: Box #56 states, “When the methods specify that CCVs shall be run at specific sample intervals (for example, every 10 samples), the count of these samples shall be of field samples only. However, QC samples must be run with their associated batches. The grouping of QC samples from a variety of batches is not an acceptable practice.”

While CCVs are not considered batch QC, they should not be grouped together with other CCVs. The intent of the language in the box is to reiterate that QC samples such as LCS, method blank, or MS/MSD are run with their associated batch not “grouped” together in the analytical run.

Question 12: Is it acceptable to use an IR device when a temperature blank is provided?

EDQW Response: It is acceptable to use an IR device to measure the temperature of a cooler temperature blank.

Question 13: Can LCS criteria be used to express uncertainty of measurement?

EDQW Response: As stated in Section 5.10.3, test reports shall include a statement of the estimated uncertainty of measurement only when required by client instruction. If a DoD project requires measurement uncertainty to be reported, the laboratory shall report that uncertainty based on project-specified procedures or, if not available, any other scientifically valid and documented procedures.

EDQW Response: The Appendix B glossary states, “Holding Times (DoD Clarification): The time elapsed from the time of sampling to the time of extraction or analysis, as appropriate.” If there are no contradictory requirements or guidance from the project or regulatory agency, DoD considers the start of extractions, distillations and digestions as equivalent for determining holding time.

EDQW Response: Appendix B Glossary states, “Limit of Quantitation (DoD Clarification): For DoD, the lowest standard of the calibration establishes the LOQ, but it must be greater than or equal to 3 times the LOD.” IUPAC and ACS set the LOQ at 10s, which is about 3.3 times the LOD. The DoD requirement for determination of LOQ is consistent with this definition.

Question 16: What should a laboratory do if their LCS acceptance criteria are more lenient than the DoD limits?

EDQW Response: Box C-8 of Appendix C.3.3.b provides requirements for Laboratory Control Samples (LCS). LCS performance outside the DoD limits is not allowed unless authorized by project-specific requirements. Evaluation of in-house laboratory limits is used to determine if a laboratory is acceptable for DoD projects. If the laboratory’s limits are wider than the DoD limits, then this indicates problems in the lab’s quality system and improvements must be made. Box C-8 of Appendix C.3.3.b states, “Precision and Bias: The mean percent recovery and standard deviation for the LCS for non-standard methods must be calculated and compared to the published DoD LCS mean percent recovery and standard deviation (Appendix DoD-D). If the laboratory generates LCS data for analytes not found in the DoD appendix, the in-house laboratory–generated limits should be used. In either case, the calculated mean and standard deviation must be at least as good as the DoD published limits, where they exist, or as good or better than the published limits for similar methods or technologies. In no case should the lower LCS control limit be less than 10%.”

DoD does not intend for LCS limits to be determined in the actual sample matrix. NELAC and the QSM define Laboratory Control Sample (LCS) as “a sample matrix, free from the analytes of interest spiked with verified known amounts of analytes …”. Laboratories do not have to spike the “actual sample matrix before actual samples are received” to comply with this requirement.

EDQW Response: Yes, clarification on this is provided in Box D-12 which states, “Spiking Compounds: The concentration of the spiked compounds shall be at or below the midpoint of the calibration range or at the appropriate level of concern. If the native concentration is known, the MS/MSD should be spiked 1-4 times that concentration.”

EDQW Response: Table B-1 in Appendix D states, “The lack of acceptable recoveries in the matrix spike often points to problems with the sample matrix. One test of this is a comparison to the LCS recoveries. If the corresponding LCS recoveries are within acceptable limits, a matrix effect is likely. The laboratory should not correct for recovery; only report the results of the analyses and the associated matrix spike results and indicate that the results from these analyses have increased uncertainty” by flagging the data appropriately.

Question 19: How were the values used in Appendix DoD-D LCS Limits developed?

EDQW Response: The LCS data were based on data submitted by commercial laboratories in 2001. The mean recovery and control limits presented in Appendix DoD-D of the DoD QSM Version 3 were based on the LCS recovery data of clean matrices (i.e., reagent water and clean solids such as soil, sand, glass beads, etc.) For more details on the LCS study, please reference the DoD LCS study report, “Development of Department of Defense Laboratory Control Sample Control Limits,” dated May 2004. The report can be downloaded from the website: http://www.navylabs.navy.mil/ManualsDocs.htm.