Determination of miroestrol and isomiroestrol from pueraria mirifica (White Kwao Krua) in dietary supplements by LC-MS-MS and LC-Q-orbitrap/MS

Abstract

The purpose of this study is to develop LC-MS-MS and LC-Q-Orbitrap/MS method for the analysis of the components of Pueraria mirifica, which are illegal additives in dietary supplements. Blank samples and samples spiked with miroestrol and isomiroestrol were used for the initial development and validation studies. Specificity, linearity, limit of quantification (LOQ), limit of detection (LOD), accuracy, precision, recovery and stability were employed as the validation parameters. The LODs of miroestrol and isomiroestrol were found to be 4.17 and 0.84 ng/mL, respectively, whereas their LOQs were 12.50 and 2.52 ng/mL, respectively. The determination coefficient was over 0.999, intra- and inter-day precisions were 0.8-6.9 and 1.9-9.8%, respectively, and intra and inter-day accuracies were 82.1-103.7 and 85.0-109.7%, respectively. The mean recoveries of the targeted compounds from the dietary supplements ranged from 86.9 to 108.9%. The relative standard deviations (RSDs) for recovery were <5.8%. On the other hand, the RSD of stability was <11.0%. Eight dietary supplements were tested using the newly developed and validated method, out of which six were found to be adulterated samples.