Quantification of staphylococcal enterotoxin type A in cow milk by using a stable isotope-labelled peptide via liquid chromatography–tandem mass spectrometry

Autor:	Hiroshi Hayashi, Junichi Kamiie, Takeo Sasamoto, Yoko Matsushima, Yukiko Nakagawa, Kotaro Sekimura, Tetsuya Shindo, Maki Kanda, Tsuneo Hashimoto, Yumi Ohba, Hiroshi Koike, Kenji Otsuka, Akihiko Hirai, Chieko Nagano
Rok vydání:	2019
Předmět:	Health Toxicology and Mutagenesis Food Contamination Enterotoxin Toxicology Mass spectrometry Enterotoxins chemistry.chemical_compound Tandem Mass Spectrometry Liquid chromatography–mass spectrometry Animals Trichloroacetic acid Reproducibility Chromatography Chemistry Stable isotope ratio Public Health Environmental and Occupational Health General Chemistry General Medicine Repeatability Milk Isotope Labeling Cattle Peptides Digestion Chromatography Liquid Food Science
Zdroj:	Food Additives & Contaminants: Part A. 36:1098-1108
ISSN:	1944-0057 1944-0049
Popis:	In this study, the staphylococcal enterotoxin type A (SEA) contaminant was quantified in cow milk by liquid chromatography-tandem mass spectrometry (LC-MS/MS) with the use of a stable isotope-labelled peptide of SEA as an internal standard. SEA was cleaned up in a two-step process that included pH control and trichloroacetic acid (TCA) precipitation. The pH control phase eliminated other proteins. TCA precipitation cleaned up SEA without special equipment. An appropriate enzyme-to-protein ratio maximised tryptic digestion. A desalting process guaranteed the stable retention of SEA-digested peptides. The coverage of amino-acid sequences (>10%) clearly identified the toxin's presence. SEA was accurately quantified using LC-MS/MS based on a multiple-reaction monitoring mode. The developed method was validated based on spiked recovery tests at 50 and 100 µg kg-1 conducted with two samples collected on a daily basis for five days based on Japanese validation guidelines. The new method exhibited good accuracy which ranged from 80% to 82%. The relative standard deviations of repeatability were 13-14% and the relative standard deviations of within-laboratory reproducibility were 13-18%. These standard deviations satisfied the criteria of the Japanese validation guidelines. The quantification limit was estimated to be 10 µg kg-1.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_dedup___::0ae6ff9c6469e515dd7c8af373caa389 https://doi.org/10.1080/19440049.2019.1615641 Zobrazit plný text záznamu Plný text ve formátu PDF Plný text ve formátu HTML
Nepřihlášeným uživatelům se plný text nezobrazuje	K zobrazení výsledku je třeba se přihlásit.