Evaluating the uncertainty in urinary fluoride measurement by ion selective electrode method

Abstract

To evaluate the uncertainty of measurement result of urinary fluoride and to provide quality assurance for determinations. The investigation was conducted, according with principles and methods for uncertainty evaluation. The uncertainty of the combined standard of present method was 2.86 %. For the sample containing 4.47 mg/L urinary fluoride, the expanded uncertainty was 0.26 mg/L. The uncertainty of the present method was mainly from the sample repeatability, the preparation of standard solution, the linearity of the calibration curve and instruments and so on.