Page 73 - Analytical method for food addtives
P. 73

E200–3: Sorbic acid and its salts  41


            Recovery check
            This should be carried out on at least one in every ten samples to be analysed. Using
            a standard solution of the five analytes add an appropriate volume (dependent on
            sample type) to a further portion of a prepared sample to be analysed, homogenise
            and apply the method procedure commencing at ‘Sample Preparation’.

            Calculation
            Determine the mean value of the two peak areas for each analyte obtained from the
            two injections made for each sample extract. Using this mean value obtain from the
            calibration graph the concentration of each of the analytes in the extract and hence
            calculate the concentration of each analyte in the sample from the formula given
            below.
            The concentration of each analyte in the sample is given by:

                                   C × 100
                   Analyte (mg/kg) = ––––––– × f                         [6.2]
                                      M

            where
            C = concentration of analyte in extract, mg/L
            M = mass of sample, g
            f  = distribution factor for extract

            Expression of results
            Report the results as mg/kg.
   68   69   70   71   72   73   74   75   76   77   78