THE PROBLEM OF DETERMINABILITY LIMIT IN S PECTROPHOTOMETRY

Three ways for finding the value of determinability limit as the funct ion of applied criteria are demonstrated on the spectrophotometric met hod for the direct determination of Fe(III) at 300 nm. Two criteria is suing from the linear regression parameters gave the values 7,7 and 8, 7 mumol/l, respectively; the value 16,1 mumol/l was found from the dep endence of relative standard deviation on Fe(III) concentration. An op timum approach to ascertaining the determinability limit is discussed from the standpoint of unequivocal criterion and limitation of subject ive factors.