ESTIMATION OF UNCERTAINTY AND VALIDATION OF ANALYTICAL PROCEDURES AS A QUALITY CONTROL TOOL THE EVALUATION OF UNCERTAINTY FOR AMINO ACID ANALYSIS WITH ION-EXCHANGE CHROMATOGRAPHY - CASE STUDY

The aim of this study was to assess the importance of validation and uncertainty estimation related to the results of amino acid analysis using the ion-exchange chromatography with post-column derivatization technique. The method was validated and the components of standard uncertainty were identified and quantified to recognize the major contributions to uncertainty of analysis. Estimated relative extended uncertainty (k=2, P=95%) varied in range from 9.03% to 12.68%. Quantification of the uncertainty components indicates that the contribution of the calibration concentration uncertainty is the largest and it plays the most important role in the overall uncertainty in amino acid analysis. It is followed by uncertainty of area of chromatographic peaks and weighing procedure of samples. The uncertainty of sample volume and calibration peak area may be negligible. The comparison of CV% with estimated relative uncertainty indicates that interpretation of research results can be misled without uncertainty estimation.