Liquid chromatography with absorbance detection and with isotope-dilution mass spectrometry for determination of isoflavones in soy standard reference materials.
Two independent analytical approaches, based on liquid chromatography with absorbance detection and liquid chromatography with mass spectrometric detection, have been developed for determination of isoflavones in soy materials. These two methods yield comparable results for a variety of soy-based foods and dietary supplements. Four Standard Reference Materials (SRMs) have been produced by the National Institute of Standards and Technology to assist the food and dietary supplement community in method validation and have been assigned values for isoflavone content using both methods. These SRMs include SRM 3234 Soy Flour, SRM 3236 Soy Protein Isolate, SRM 3237 Soy Protein Concentrate, and SRM 3238 Soy-Containing Solid Oral Dosage Form. A fifth material, SRM 3235 Soy Milk, was evaluated using the methods and found to be inhomogeneous for isoflavones and unsuitable for value assignment. Graphical Abstract Separation of six isoflavone aglycones and glycosides found in Standard Reference Material (SRM) 3236 Soy Protein Isolate.
Chemical Sciences Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, 20899-8392, USA. melissa.phillips@nist.gov.
Melissa M
MM
Phillips
Chemical Sciences Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, 20899-8392, USA.
Mary
M
Bedner
Institute of Organic Chemistry, University of Tübingen, Auf der Morgenstelle 18, 72076, Tübingen, Germany.
Manuela
M
Reitz
Chemical Sciences Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, 20899-8392, USA.
Carolyn Q
CQ
Burdette
Chemical Sciences Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, 20899-8392, USA.
Michael A
MA
Nelson
Statistical Engineering Division, Information Technology Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, 20899-8980, USA.
James H
JH
Yen
Chemical Sciences Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, 20899-8392, USA.
Lane C
LC
Sander
Chemical Sciences Division, Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, MD, 20899-8392, USA.
Catherine A
CA
Rimmer
D002853:Chromatography, Liquid / Q000379:methods*; D007529:Isoflavones / Q000032:analysis*; D007554:Isotopes; D013058:Mass Spectrometry; D066244:Proton Magnetic Resonance Spectroscopy; D012015:Reference Standards; D045730:Soy Foods / Q000032:analysis*; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*
D007529:Isoflavones; D007554:Isotopes
Isoflavones; Reference material; Soy