Assessment of limits of detection and quantitation using calculation of uncertainty in a new method for water determination

An approach to the assessment of the limit of detection and the limit of qu antitation using uncertainty calculation is discussed. The approach is base d on the known evaluation of the limits of detection and quantitation as co ncentrations of the analyte equal to three and ten standard deviations of t he blank response, respectively. It is shown that these values can be calcu lated as the analyte concentrations, for which relative expanded uncertaint y achieves 66% and 20% of possible results of the analyte determination, co rrespondingly. For example, the calculation is pet-formed for the validatio n of a new method for water determination in the presence of ene-diols or t hiols, developed for analysis of chemical products, drugs or other material s which are unsuitable for direct Karl Fischer titration. A good conformity between calculated values and experimental validation data is observed.