The author indicates blank subtraction or recovery addition are not recommended in the field. Do you agree with this approach?

Answer Explanations

• Yes

  Expert 9
  As stated elsewhere, I am an advocate of leaving such adjustments to the reader if they are to be made at all. To facilitate this, all data should be reported to permit this if at all possible.
• Yes

  Expert 3
  I was somewhat divided on this, but it is likely best to include the raw data and then these additional values. However, data reporting should be clear on this (whether the values were subtracted or not) in order to minimize confusion. 
• No (please explain)

  Expert 4
  I acknowledge the difficulties associated with blank subtraction and correction for recovery and the consequences for the final quantification. However, blanks and recoveries below 100 % as identified using well-established analytical procedures, and as determined in procedural samples, are indicative of non-optimal perofrmance of the method for field samples. This implies that it is always necessary to correct for blanks and recoveries and to do so at the lowest possible level of quantification - this often is the extract/digest that is directly injected in the analytical devise. In correcting for the performance of blanks and for recoveries, also the uncertainties/standard deviations need to be considered. 
• No (please explain)

  Expert 1
  In environmental chemical analysis, blank subtraction is routinely followed. As long as blanks are well characterized and blank data are qualified, one should subtract blank values.  In some cases, it may yield negative values because blank concentrations are higher than those in samples.  That also means that the variability of blank levels is high.  That help readers understand the need for exercising caution in interpreting data.  It is prudent that both raw data and blank subtracted data are made available and compared.   The authors' statement may be true for FTIR and spectroscopy based methods, but when mass spectrometric methods are used, blank subtraction is meaningful.  Again, it is all about being transparent and in the end, expert judgement is needed.
• No (please explain)

  Expert 6
  We can use blank subtraction only when there is consistent and known background contribute to samples. Recovery addition should be tested, as it will help to determine the accuracy of testing method and sampling approach.