title: Development of an SI-Traceable HPLC-Isotope Dilution Mass Spectrometry Method To Quantify β-Lactoglobulin in Milk Powders.
abstract: β-Lactoglobulin (β-LG) is one of the major allergenic proteins in milk. There is an urgent demand for an accurate and traceable method to develop β-LG certified reference material (CRM). In this work, β-LG was enzymatically digested and a specific peptide was chosen for quantitation by isotope-dilution mass spectrometry (IDMS). With amino acid CRMs as standards, the results could be traced to SI unit. By the proposed method, the recovery ranged from 86.0% to 118.3% with CVs <9.0%. The LOD and LOQ were 4.8 × 10-5g/g and 1.6 × 10-4g/g of β-LG in milk powder, respectively. Ten samples from domestic market were analyzed with CVs <5.6%, and the relative expanded uncertainties ranged from 4.2% to 5.9% (k = 2). With the CRMs, it is expected that the comparability of β-LG quantitation results will be improved among different laboratories.
authors.affiliation: College of Science, Beijing University of Chemical Technology , Beijing, 100029, People's Republic of China.
authors.forename: Wang
authors.initials: W
authors.lastname: Yang
authors.affiliation: Division of Medical and Biological Measurement, National Institute of Metrology , Beijing, People's Republic of China.
authors.forename: Wu
authors.initials: W
authors.lastname: Liqing
authors.affiliation: College of Science, Beijing University of Chemical Technology , Beijing, 100029, People's Republic of China.
authors.forename: Duan
authors.initials: D
authors.lastname: Fei
authors.affiliation: Division of Medical and Biological Measurement, National Institute of Metrology , Beijing, People's Republic of China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Bin
authors.affiliation: College of Science, Beijing University of Chemical Technology , Beijing, 100029, People's Republic of China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yi
authors.affiliation: Division of Medical and Biological Measurement, National Institute of Metrology , Beijing, People's Republic of China.
authors.forename: Wang
authors.initials: W
authors.lastname: Jing
keywords: HPLC−IDMS; allergen; liquid chromatography isotope dilution mass spectrometry; milk powder; β-lactoglobulin