. Conclusions
It is well known that ascorbic acid is a sensitive and thermo-labile compound, so its extraction with high yield and without any decomposition has been a matter of difficulty and labor-intensive for the analysts. The freezing sample preparation method prevents oxidation and degradation of ascorbic acid and affords enough sensitivity and selectivity in extraction of ascorbic acid in dog rose (at three maturity stages) and orange sample. Also the proposed LC method has good resolution from other contaminants or the solvent peak. The method delivers results within 6.1 min after fruit extraction. The proposed method can be used to identify and quantify vitamin C in a wide variety of fruits. Finally, the stability of ascorbic acid in the presence of fruit matrix is higher than the fruit extracts at room temperature.