ESTIMATION OF THE TOLERANCE LEVEL OF INTERFERING SUBSTANCES IN INSTRUMENTAL ANALYTICAL METHODS

A model to estimate the tolerance level of interfering substances for analytical procedures, applying the linear simple regression, is propo sed. The confidence interval on the analytical signal for the selected concentration value to check the interference, is calculated using th e calibration data set. The tolerance levels of molybdenum, aluminium and iron in the spectrofluorimetric determination of boron with Alizar in Red S by means of direct, synchronous and first- and second-derivat ive methods, are estimated. The adequate selection of an analyte conce ntration for the interferent test is discussed.