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Procedures for Detection and Quantitation

Technical Workgroup

Federal Advisory Committee on Detection and Quantitation Approaches and Uses in Clean Water Act (CWA) Programs

Summary of Technical Work Group Conference Call #38
September 27, 2006
1:00 – 3:00 p.m. EST

The call-in number for all calls is 866 299-3188 and the participant code is 202 566 1045#. The schedule of future Technical Work Group conference calls is:

Action Items

The Intermittent Blank Contamination Subgroup will revise the draft discussion paper based on discussion at this meeting and circulate to the Technical Work Group for discussion at its next meeting. John Phillips will coordinate a meeting of the subgroup. Richard Burrows will be added to the list of subgroup participants.

Ken Miller will:

John Phillps will discuss with Richard Reding the possibility/need of adding other analyses to the pilot study (e.g. normality testing).

Triangle will:

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Welcome and Introductions

Bob Wheeler, facilitator, welcomed participants to the call at 1:00 p.m., conducted a roll call of Technical Work Group (TWG) members and observers, and briefly reviewed the agenda for the meeting. He said that the focus of this meeting was on the Procedures 101 presentations, and a discussion of the document on intermittent blank contamination.

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Meeting Summary Approval

Mr. Wheeler asked for comments to the draft September 13 meeting summary. Nicole Shao suggested a revision in the action item for her stating that "...comparison of the numerical detection and quantitation limits derived by the procedures may not be appropriate." She also suggested a corresponding change to the summary on page 3. The group agreed to the suggested change and approved the summary as revised.

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Status Updates: FACDQ Extension, Pilot Study and MMA Data

Bob Wheeler gave a brief update on the status of the charter extension, referring the group to an email from Richard Reding dated 9/26/06. EPA is preparing the paperwork for an extension in the event there is significant progress made at the December committee meeting and Michael Shapiro approves the extension.

Ken Miller commented on the status of the pilot study saying that the deadline for receiving the historic blank data from the participating labs is tomorrow, September 28. Labs are now evaluating the ACIL procedure, and the data from the evaluation of that procedure is due October 12. The schedule has not changed since the last call. John Phillips commented that he had seen the calculations from one of the participating labs; it was a pretty comprehensive spreadsheet.

Bob Wheeler asked Ken Miller if the labs were still required to answer a series of questions regarding the feasibility of performing the procedure. Mr. Wheeler said his recollection was that the TWG originally developed a series of questions that were supposed to be incorporated in the RFP sent to the labs. Ken Miller responded that they have received some comments from participating labs, which are being recorded, but that the overall feasibility of performing the procedure would also be incorporated in each lab's narrative report at the end of the pilot study. Mr. Wheeler asked Mr. Miller to confirm whether a series of questions was also included in the RFP. Mr. Miller said he would do that.

With regard to the MMA data set, Mr. Miller said that he had sent to the group two sample spreadsheets with preliminary analyses for the datasets that included the misidentified Aroclor with no outlier removal. There was some email discussion of whether to include the limits in the analyses, but Mr. Miller said he had not done that because the TWG had previously discussed the desire to put these in the appendix of the pilot study report. The group confirmed that decision to publish the limits in an appendix to the final report, saying the focus was on whether the procedure met the established MQOs.

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Technical Work Group Schedule

Mr. Wheeler reviewed the group's schedule of topics for upcoming meetings. He said the intent for the next committee meeting was to stay policy-focused. The facilitation team is trying to keep to a minimum the number of documents that the committee will need to review in advance of the meeting. Therefore, the focus of material for the TWG will be for the evening presentation of the first day of the meeting (December 6). That presentation will cover a status update of the pilot study, Procedures 101, and data calculations and analyses.

John Phillips referenced a recent exchange of emails among some members of the group discussing the possibility of adding additional evaluation criteria and calculations to the analyses of the pilot study. He suggested the TWG or Pilot Study Design Team could come up with a recommendation for the committee to consider if the group believes additional calculations were needed. Bob Wheeler suggested the group discuss this more at the end of the meeting, time permitting.

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Procedures 101 Presentation

Bob Wheeler suggested that since few revised presentations had been received since the last TWG meeting, perhaps the focus of this discussion should be on the analysis of the 15 characteristics across all the procedures that Triangle drafted based on responses in each of the presentations. He also described for the group a draft agenda for the evening presentation on December 6.

The group added a couple of editorial comments, such as changing one column title from "Multi-lab Procedures" to "Inter-lab Procedures," and moving the LC-MRL/H-V left one column. The group began discussing the basis for some of the responses in the summary spreadsheet.

Mr. Wheeler encouraged the group to withhold that judgment until the next TWG meeting (October 11) when the group would discuss a normalized matrix that Ken Miller was working to complete. The group agreed that would be a more effective approach. Then, Mr. Wheeler said, the responses from the matrix could go back into each of the presentations and into the summary spreadsheet of all 15 characteristics as a handout for the evening presentation.

There was a suggestion to consolidate answers where the group agrees (i.e. either Yes or No across all procedures), and instead focus on the differences between procedures in the individual procedure presentations. Mr. Wheeler reminded the group that once the presentations were complete, Triangle would pull all of the slides into one presentation, consolidate the areas where there was duplication of information and develop a few introductory slides to address those issues of commonality.

Before moving on, the group focused on characteristic #5 (provide that qualitative identification criteria defined in the analytical method are met at the determined detection and quantitation limits) and its meaning. After a lengthy discussion, the group agreed that this criterion was meant to address whether the procedure included an explicit test for this and that it was not only a technical issue, but also one of use.

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Features Document

Bob Wheeler explained that at the last committee meeting, there was a request to revise the document describing the features of the pilot study to more explicitly address what the pilot study will not do. Mr. Wheeler explained that Triangle used an earlier document from John Phillips as the basis for incorporating many details of what the pilot study would not do. In the spirit of keeping documents focused for the December committee meeting, Mr. Wheeler also suggested that the committee not receive this revised features document until the May 2007 meeting, when it will be discussing the pilot study.

The group agreed that the document appeared to reflect the earlier concerns of what the pilot study will not do and that it would be more appropriate to distribute the document in advance of the May 2007 meeting.

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Intermittent Blank Contamination

John Phillips briefly reviewed the document developed by the subgroup. The document contains five sections:

  1. Evaluation of the method blank
  2. False negative quality control standard (FNQS)
  3. Batch data qualifications
  4. Method detection and quantitation limits
  5. Process for finding and correcting intermittent blank contamination

Tim Fitzpatrick added that the subgroup had been talking about method blank contamination for two reasons: reporting and setting method detection limits. Mr. Phillips said the subgroup and subsequent email discussions were considerably focused on section 4. He said that Richard Burrows had responded to the complexity of the recommendation in real world implementation and had proposed an alternative approach.

Mr. Burrows approach calls for evaluating the first 20 blanks. If 19 of those give a result below the DL, then the calculated DL would be used. If that is not the case, then the highest blank result would be used as the DL. The results would be re-evaluated once per year. If less than 2% of the blanks are greater than the calculated DL, then the calculated DL would continue to be used. If greater than 2% of the blanks are greater than the calculated DL, then the level that is exceeded by 1% of the blanks is used as the DL.

After a fairly lengthy discussion on the topic of how method blank contamination could be identified, the subgroup agreed to go back into their document and continue discussions based on feedback from the group. Richard Burrows agreed to be a part of the subgroup discussions to assist in simplifying the method detection and quantitation limits approach. John Phillips will arrange a conference call meeting in the near future.

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Report on Policy Work Group Discussions

Mr. Wheeler briefly reviewed the Policy Work Group schedule of activities, highlighting current work on a hybrid approach to method promulgation and method updating, uses, and matrix effects. He said that the latter could soon become an assignment from the Policy Work Group, depending on progress at its next meeting tomorrow, September 28. Larry LaFleur added that Triangle had distributed to the TWG a document drafted by Mr. LaFleur regarding matrix effects. Nicole Shao asked for clarification on when the matrix effects document was sent. Mr. Wheeler said it was sent by Derek Van Marter via email on September 13.

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Public Comment

There were no public comments.

Wrap-up and Closing

Mr. Wheeler summarized the items coming forward for the October 11 meeting:

  1. Status of FACDQ extension
  2. Update on Pilot Study; MMA Data Evaluation
  3. Normalized Matrix
  4. Intermittent method blank contamination
  5. Ongoing verification/matrix effects
  6. Definitions rationale

Mr. Wheeler thanked everyone for their time and adjourned the meeting at 3:00 PM, ET./p>

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Attendance

Technical Work Group Members

Triangle Associates: Robert Wheeler and Derek Van Marter

Observers

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