VALIDATION OF A PROCEDURE FOR QUANTIFYING THE AMOUNT OF FLAVONOIDS IN IN THE GROUND BURNUT (TRIBULUS TERRESTRIS) HERB

Introduction. To standardize the raw materials of ground burnut (Tribulus terrestris) herb, the authors have developed a procedure to measure the amount of flavonoids calculated with reference to rutin. To ensure that this procedure guarantees reliable and accurate test results, a technique is provided to validate the developed procedure. Objective: to validate a procedure for quantitative determination of the amount of flavonoids calculated with reference to rutin in the ground burnut herb, by using differential spectrophotometry. Material and methods. The procedure was validated on a combined sample of ground burnut herb. The validation parameters were determined using SF-2000 and SHIMADZU UV-1800 spectrophotometers. Results. The investigators established validation characteristics, such as linearity, precision (repeatability, reproducibility), and accuracy. Linearity was determined at five concentration levels. The correlation coefficient was 0.995, which indicates a linear relationship between the optical density and the total flavonoid content in extracts. The repeatability of the procedure was determined with tenfold replication under identical conditions within a short time interval. The intralaboratory reproducibility of the procedure was determined using three samples in triplicate. Its interlaboratory reproducibility was carried out on three samples in triplicate in two laboratories. The determination results confirmed the precision of the procedure under intralaboratory and interlaboratory reproducibility conditions, since the relative standard deviation did not exceed 15%. The accuracy of the procedure was established by adding the required amount of the standard to the extract. The results showed that the error in analysis was within the error in one determination and did not exceed 2.89%. Conclusion. The developed procedure is valid for the spectrophotometric determination of the sum of flavonoids calculated with reference to rutin in the ground burnut herb. The procedure requires no expensive reagents, is accurate, reproducible, and affordable, which allows it to be used for a reliable assessment of the quality of raw materials.

Tribulus terrestris L, validation, procedure, ground burnut, Tribulus terrestris L, herb, flavonoids, spectrophotometry