engleski

Validation of an automatic spectrophotometric method for total sulphite determination in wine

The maximum acceptable concentrations of the sulphite species in foodstuffs are defined in specific legislation. Due to its widespread and historic use in the wine protection a number of analytical methods exist for sulphite measurement. The aim of this work was to develop the spectrophotometric method for determination of total sulphite in wines (white and red). To demonstrate that analytical method of choice is suitable for its intended purpose, appropriate experimental work was designed to provide validation parameters: accuracy, precision and linearity. The results obtained showed that method is accurate at 95.4 % of average recovery which indicates agreement between reference and obtained values. Evaluated data showed high level of precision (1.4 and 0.5 % average RSD for repeatability of measurement and standard solution preparation, respectively). Calculated correlation coefficients (0, 9999), y-intercept, slope of the regression line and residual sum of squares are demonstrating the linearity of the method. Comparison of results obtained by reference and spectrophotometric methods shows high coherence (r=0.9872). It should be stressed that this method has been successfully applied to routine analysis.

wine; total suphite; spectrophotometry

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