To the question of standardization of raw materials of strawberry (Fragaria × ananassa)

In order to standardize the raw materials of garden strawberries, we have developed a method for quantifying the amount of flavonoids in terms of ru-tin. The article presents the results of validation of the method of quantitative determination of the amount of flavonoids in terms of rutin in strawberry leaves to prove the guarantee of accuracy and reliability of the results of the analysis of raw materials and its subsequent application in the quality as-surance system of research. Purpose. Validation of the method of quantitative determination of the amount of flavonoids in terms of rutin in strawberry leaves using the method of differential spectrophotometry. Material and methods. Validation of the method was performed on a combined sample of strawberry leaves. Validation parameters were deter-mined using SF–2000 and SHIMADZU UV–1800 spectrophotometers. Results. Linearity was determined at five levels of concentration. The correlation coefficient was 0.9997, which indicates a linear relationship between the values of the optical density and the content of the sum of flavonoids in the extracts. The repeatability of the technique was determined in tenfold repetition under identical conditions within a short period of time. The intra-laboratory reproducibility of the technique was determined on three samples of three-fold repetition. Interlaboratory reproducibility of the technique was performed on three samples in three-fold repetition in two laboratories. The results of the determination confirm the precision of the method in the conditions of intra-laboratory and inter-laboratory reproducibility, since the rela-tive standard deviation did not exceed 15%. The correctness of the method was established by adding the required amount of standard routine to the extraction. The results of the analysis showed that the analysis error is within the error of a single definition and does not exceed 2.24%. As a result of the conducted studies, the validation characteristics of the method for quantifying the amount of flavonoids in terms of rutin in the leaves of strawberry garden were established: linearity, precision (repeatability, reproducibility) and correctness. Conclusions. The developed method of spectrophotometric determination of the amount of flavonoids in terms of rutin in strawberry leaves is valid, does not require expensive reagents, is accurate, reproducible and accessible, which makes it possible to use it for a reliable assessment of the quali-ty of raw materials.