Estimation of the uncertainty of the quantification limit

• We proposed an approximated formula for the standard deviation of the detection limit.
• We calculated the standard deviation of the quantification limit.
• We successfully compared them with the modified noncentral t distribution ones.
• We applied them to easy interpret calibrations of some elements by ICP-MS.
• They allowed an easy comparison of different operating conditions.

A method to compute the standard deviation of detection and quantification limits based on an easy equation was proposed. The results were compared to those coming from the rigorously theoretical approach proposed in the literature which required quite complex computations. The results were in excellent agreement with the theoretical ones. The proposed equation represents an easy tool to establish whether an instrumental technique furnishes equivalent results in different operating conditions and to compare a limit of quantification to a law limit. The application to an experimental calibration of some elements by ICP-MS technique demonstrated its easy use for the interpretation of the results.