1. Chromatographic separation of benzoic and sorbic acids.
The external standard method (ESTD) was used to the chromatographic system for benzoic and sorbic acid quantification Mixed benzoic and sorbic acids ranging from 5-40 ppm were used to standard solution. Linearity between the
concentration of benzoic and sorbic acids and the UV absorbance at 240 nm was obtained and
correlation coefficient for each standard curve exceeds 0.9980. Figure 1 show the separation
of mixture of benzoic and sorbic acid. Each compound was identified by its retention time
in comparison with standard solution of pure compounds, The detection limit were 1 and 2 ppm for benzoic and sorbic acids respectively.
2. Extraction of benzoic and sorbic acids : The extraction of benzoic and sorbic acids in the sample by steam distillation, followed by HPLC analyzed. These method were good and gave accurate and precise results in short period
of time. Table 1 shows extraction recoveries for benzoic and sorbic acids spiked at different concentration indicate that the benzoic and sorbic concentration have not effect to % recoveries at 90-107 and 87-118 % for benzoic and sorbic acids, respectively .