Quantitative determination of osteopontin in bovine, buffalo, yak, sheep and goat milk by Ultra-high performance liquid chromatography-tandem mass spectrometry and stable isotope dimethyl labeling. (1st May 2021)

• Record Type: Journal Article
• Authors: Hu, Bei; Zhang, Jingshun; Jiang, Yirong; Tong, Wenfeng; Lai, Shiyun; Ren, Yiping
• Is Part Of: Food chemistry. Volume 343(2021)
• Publication Date: 2021-05-01
• Subjects: Osteopontin -- Dimethyl labeling -- Solid phase extraction -- Ultra-high performance liquid chromatography -- Mass spectrometry; Food -- Analysis -- Periodicals; Food -- Composition -- Periodicals; 664
• DOI: 10.1016/j.foodchem.2020.128489
• Languages: English
• ISSNs: 0308-8146

Abstract

Highlights: An UHPLC-MS/MS method was developed to determine OPN in milk. A consensus signature peptide was selected as the representative of OPN from different species' milk. Stable isotope dimethyl labeling was used to prepare internal standard during determination of OPN. HLB cartridge was applied to purify and enrich OPN signature peptide. The method was able to measure OPN content in bovine, buffalo, yak, goat and sheep milk. Abstract: Osteopontin (OPN) is a multifunctional protein present in different tissues, body fluids and milk. Different milk has different level of OPN content. To determine the amount of osteopontin in bovine, buffalo, yak, sheep and goat milk, we developed an ultra-high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method to detect an osteopontin signature peptide. The signature peptides selected by searching Uniprot database for trypsin digested osteopontin. The sample preparation procedure includes trypsin digestion, dimethyl labeling of tryptic peptides, purification and concentration of labeled tryptic peptide with solid phase extraction. The limit of detection and limit of quantification are 0.5 mg L −1 and 2.0 mg L −1, respectively. The method has satisfactory analytical performance with a linearity of R 2 ≥ 0.998, recoveries of 103.7–111.0%, and precision of 1.8–6.2%. It is also validated and successfully applied to quantifying osteopontin content in bovine, buffalo, yak, sheep and goat milk.