difference to range in any given case yielded a value which could be ex ceeded by chance alone less than 10% of the time, the observation was desig nated as inconsistent with the rest and therefore not used for evaluation of the performance of the analyst for the par ticular method. Each individual tested received at least three different concentration levels on the nine test samples for each method. All test samples were supplied by the Standards Laboratory which is in a Group of the Analytical Section, su pervised independently from the Shift Control Laboratory. Where experi enced personnel were tested, these sam ples were used for the current quality control program. Single determinations for each sample were made and reported; however, enough sample was supplied for duplicates, in case a spill or loss of sample during pipetting made it neces sary to repeat the analysis. Table I is a list of methods (7) in cluded in the program. All methods used in the laboratory were not included in this program since techniques used in some methods are the same as those used in others. Be cause of the unstable nature, it was im possible to prepare testing samples ac curately for several methods; therefore, they were not included in this program. Statistical Analysis Results. Ex perienced employees were tested on methods which they were routinely using. New employees are trained, using a known standard. The stand ard is processed nine different times. Answers from these standards are evalu ated statistically and satisfactory results must be obtained before a new employee is allowed to analyze unknown test samples. As complete sets of data on a method were obtained for an individual, they were statistically analyzed. The following information was reported to laboratory supervision as a result of the statistical analysis on each set of data submitted by an analyst.
Table I.
1. 2. 3. 4. 5. 6.
Methods Included in Training and Testing Program
Colorimetric determination of uranium Fluorophotometric determina tion of uranium Isotopic dilution determination of uranium Titrimetric determination of Hg(II) Titrimetric determination of aluminum Potentiometric determination of free acid
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