A New Detection Method for the Biomarkers of Soybean Isoflavones in Human Urine on the Basis of Packed-Fiber Solid-Phase Extraction.

Traditional dietary assessment methods such as 24-h dietary recall methods are not accurate enough, and the biomarkers to objectively evaluate food consumption have become attractive recently. Soy isoflavones are a typical plant-based estrogen that helps to slow menopause symptoms, helping to lower cholesterol levels and reduce the risk of arteriosclerosis, and studies have shown a significant correlation between urinary isoflavones excretion and soy intake, which can be used as a useful biomarker. Because of the complex urine sample matrix and the large range of isoflavone concentration, it is vital to develop a new detection method to decrease the impurities interference and increase the target concentration for accurate detection of urine isoflavones. In this study, a few types of nanofibers were prepared and utilized as solid-phase extraction adsorbents for sample pretreatment, and the homemade packed-nanofiber solid-phase extraction columns were chosen to purify the matrix and concentrate the analytes. A new method for rapid detection of soybean isoflavones in urine on the basis of packed-fiber solid-phase extraction combined with ultraviolet spectrophotometer was established, which provides an efficient reference for assessment of individual dietary intake.