title: Determination of ochratoxin a in ready-to-drink coffee by immunoaffinity cleanup and liquid chromatography-tandem mass spectrometry.
abstract: We developed a simple and accurate method for determining ochratoxin A (OTA) in ready-to-drink coffee, using an immunoaffinity column for cleanup and liquid chromatography-tandem mass spectrometry (LC/MS/MS) for identification and quantification. When uniformly stable isotope-labeled OTA (U-[(13)C(20)]-OTA) was employed as an internal standard, the recovery rate of the method was 97.3% (the spiked OTA level was 0.10 ng/mL), the repeatability (relative standard deviation) was 1.9%, and the intermediate precision (relative standard deviation) was 4.0%. The limit of quantification was 0.0065 ng/mL based on a signal-to-noise ratio in coffee of 10:1. The developed method was used for the determination of OTA in ready-to-drink coffee. A total of 30 ready-to-drink coffee samples commercially available in Japan were analyzed. OTA was detected in all of the samples at concentrations ranging from trace levels (0.0020-0.010 ng/mL) to 0.037 ng/mL. This method was shown to be useful for accurately evaluating the intake of OTA from coffee beverages.
authors.affiliation: Research Laboratories for Food Safety Chemistry, Asahi Breweries, Limited, Moriya-shi, Ibaraki 302-0106, Japan. shigekuni.noba@asahibeer.co.j
authors.forename: Shigekuni
authors.initials: S
authors.lastname: Noba
authors.forename: Atsuo
authors.initials: A
authors.lastname: Uyama
authors.forename: Naoki
authors.initials: N
authors.lastname: Mochizuki
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D003069:Coffee / Q000737:chemistry*; D007118:Immunoassay / Q000379:methods*; D009183:Mycotoxins / Q000032:analysis*; D009793:Ochratoxins / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D003069:Coffee; D009183:Mycotoxins; D009793:Ochratoxins; C025589:ochratoxin A