D. Georgieva1, I. Tringovska2*, A. Atanasova2, V. Kmetov1
1Department of Analytical Chemistry and Computer Chemistry,Faculty of Chemistry, Plovdiv University Paisii Hilendarski, 24 Tzar Assen, 4000 Plovdiv, Bulgaria
2Departmen of Plant Nutrition, Maritsa Vegetable Crops Research Institute, 32 Brezovsko shosse, 4003 Plovdiv, Bulgaria
Abstract. Quality control of analytical procedure is required for any amended or new method to ensure its applicability and capability to produce reliable results. This study shows an optimized method for high performance liquid chromatography (HPLC) analysis of some polyphenolic acids and flavonoids in tomato fruits. Efficient separation of chlorogenic acid, caffeic acid, p-coumaric acid, ferulic acid, rutin, myricetin, naringenin and quercetin was achieved on Poroshell 120 reverse-phase column С18 (75 mm x 4.6 mm x 2.7 μm) by gradient elution with mobile phase А (0.5% Acetic Acid), mobile phase B (1:1 mix of 0.5% Acetic acid and Acetonitrile) and mobile phase C (Acetonitrile). Some analytical features of the method such as limit of detection (LOD), limit of quantification (LOQ), linearity and precision were estimated after testing of an eight-compound mixture of the single reference phenolic compounds at seven concentrations. It was found that LOQ is from 0.02 to 0.63 ppm, for the included analytes with linear quantitative response up to 10 ppm. The method precision was estimated as measurement repeatability and intra-laboratory reproducibility. The relative standard deviation (RSD) obtained after analyzing 3 replicates and 7 concentrations varied from 0.1 to 12.6%. These results suggest that the optimized method has a good potential for simultaneous quantification of the above mentioned hydroxycinnamic acids and flavonoids in tomato fruits.