title: Accurate determination of ochratoxin A in Korean fermented soybean paste by isotope dilution-liquid chromatography tandem mass spectrometry.
abstract: Ochratoxin A (OTA), a naturally occurring mycotoxin, has been frequently detected in doenjang, a traditional fermented soybean paste, when it is fermented under improper conditions. Reliable screening of OTA in traditional fermented soybean paste (doenjang) is a special food-safety issue in Korea. Our laboratory, the National Metrology Institute of Korea, established an isotope dilution-liquid chromatography tandem mass spectrometry (ID-LC/MS/MS) method as a higher-order reference method to be used for SI-traceable value-assignment of OTA in certified reference materials (CRMs). (13)C20-OTA was used as an internal standard. Sample preparation conditions and LC/MS measurement parameters were optimised for this purpose. The analytical method was validated by measuring samples fortified with OTA at various levels. Repeatability and reproducibility studies showed that the ID-LC/MS/MS method is reliable and reproducible within 2% relative standard deviation. The analytical method was applied to determine OTA in various commercial doenjang products and home-made doenjang products.
authors.affiliation: Division of Metrology for Quality of Life, Korea Research Institute of Standards and Science, Yuseong, Daejeon 305-600, Republic of Korea.
authors.forename: Seonghee
authors.initials: S
authors.lastname: Ahn
authors.affiliation: Division of Metrology for Quality of Life, Korea Research Institute of Standards and Science, Yuseong, Daejeon 305-600, Republic of Korea.
authors.forename: Suyoung
authors.initials: S
authors.lastname: Lee
authors.affiliation: Division of Metrology for Quality of Life, Korea Research Institute of Standards and Science, Yuseong, Daejeon 305-600, Republic of Korea.
authors.forename: Joonhee
authors.initials: J
authors.lastname: Lee
authors.affiliation: Division of Metrology for Quality of Life, Korea Research Institute of Standards and Science, Yuseong, Daejeon 305-600, Republic of Korea. Electronic address: Byungjoo@kriss.re.kr.
authors.forename: Byungjoo
authors.initials: B
authors.lastname: Kim
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D005285:Fermentation; D007554:Isotopes / Q000032:analysis; D057230:Limit of Detection; D009183:Mycotoxins / Q000032:analysis*; D009793:Ochratoxins / Q000032:analysis*; D015203:Reproducibility of Results; D056910:Republic of Korea; D013025:Glycine max / Q000737:chemistry*; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D007554:Isotopes; D009183:Mycotoxins; D009793:Ochratoxins; C025589:ochratoxin A
keywords: Fermented soybean paste; Isotope dilution mass spectrometry; Ochratoxin A; Ochratoxin A (PubChem CID: 1001246)