ABSTRACT
BACKGROUND: The use of the extracts from evening primrose seeds as a health functional food has been gradually increased. Therefore, the monitoring and screening process has been considerably required for its quality control. OBJECTIVE: This study aimed to estimate the measurement uncertainty associated with determination of penta-o-galloyl β-D-glucose (PGG) in extracts from evening primrose seeds by high-performance liquid chromatography. METHODS: The sources of measurement uncertainty was expressed in accordance with mathematical/statistical theories of GUM & EURACHEM Guide. The expanded uncertainty was calculated by using the relative standard uncertainty between analytical result and sources of uncertainty in measurement (sample weight, final volume, extraction volume, standard solution, matrix and instrument etc). RESULTS: In the results of 95% confidence interval, the uncertainty in measurement was 10,253.34 ± 1,844.50 µg/kg (k = 2.0). CONCLUSION: In this study, it showed that the value of uncertainty in measurement for determination of PGG in extracts from evening primrose seeds by HPLC has about 18.0% influence on PGG contents of the analytical results. The results would be very useful for the monitoring and screening of evening primrose seeds marketed in Korea for its quality control as dietary supplement.