Results
(8 Answers)

Expert opinions are divided on whether procedural blanks should produce LODs for correcting individual test samples in the absence of paired blanks.

In favor (5 experts):

  • Experts 2, 4, 1, 6, and 8 generally support using procedural blanks to produce LODs
  • Expert 6 explicitly supports correcting individual test samples using procedural blanks
  • Expert 8, however, recommends against "correction" or blank subtraction despite supporting LOD calculation
  • Expert 1 notes that this approach has uncertainties that should be documented

Against (3 experts):

  • Experts 9, 5, and 7 oppose this approach
  • Expert 9 recommends reporting all raw data without corrections
  • Expert 7 specifically states LOD should define minimum detection concentration, not serve as a correction factor
Summary Generated by AI

Answer Explanations

  • Expert 3
    In case there are no paired blanks, LOD should be used as a threshold, not a subtractive correction. If the sample is below LoD, report LoD, if not, report the quantity. In cases in which there is a high blank variability, use LOQ or replicate blanks for better confidence

  • No
    Expert 9
    I would not report data corrected for blank levels. Rather, I would provide data for all samples and blanks, to permit other researchers to assess the validity of the data provided.
  • Yes (please explain)
    Expert 2
     In situations where  the paired blanks are unavailable, the procedural blanks can be utilized to have an estimation of the background contamination and inform the calculation of Limits of Detection (LODs). However, they should not be used to directly generate LODs for the purpose of uniformly correcting all individual test samples based on those values. 
  • Yes (please explain)
    Expert 4
    For the time being this is a possible solution indeed. Here too it is needed to correct at the basic level of (raw) data gathering.
  • Yes (please explain)
    Expert 1
    Yes, procedural blanks can help produce LODs, although there are uncertainties associated with mean values of MNPs measured in blanks.  MNP contamination in blanks vary widely.  As long as those uncertainties are documented, analyst can use the best judgement.  Nevertheless, with emerging methodologies involving pyrolysis GCMS, it is not just blanks, but also instrumentation and sample mass that can dictate LOD values.  So there is no one size that fits all, in answering the question.  It depends, and in the end the rigor of analysis should be documented in reporting.
  • Yes (please explain)
    Expert 6
    Yes, LODs and LOQs should be regenerated using procedural blanks, and individual test samples should be corrected by the signal or response of procedural blanks.
  • Yes (please explain)
    Expert 8
    Yes, LODs should be calculated using the blanks as well as the instrument's level of detection.  Samples that are below the LOD should be reported as below that number without stating the actual measured value. "Correction" of the values (aka blank subtraction) is not suggested.
  • No
    Expert 7
    Limit of detection is to be used to define the minimum detection concentration. It should not be used as a correction factor. 

0
Expert 7
07/31/2025 09:09
In my practice, I do not use LOD to do correction. In general, I just report the number. 
0
Expert 5
07/31/2025 12:10
Signals from blanks that are above a standard sample LOD should cause the analyst to reexamine the analytical schema for ways to lower those blank signals below the LOD of a standard sample.
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