Interval estimates of total concentrations. Calculation of the intervals
When total concentration of similar analytes (hydrocarbons or phenols in waste waters etc.) is estimated, it is often recalculated to the reference substance (standard, Xst). The different sensitivities for the analytes and Xst during the measuring of total signal, result in the unpredictable systematic errors. The derived formulas are valid to calculate the limits for the actual meaning of estimated concentration. The amplitude of the interval is an objective appraisal of an estimate accuracy, which does not depend on the qualitative and quantitative composition of the investigated mixtures. The interval amplitude grows as the sensitivities of similar analytes determination with this method are differed.