摘要
椰毒假单胞菌酵米面亚种易污染银耳、酵米面等,米酵菌酸(Bongkreic acid,BA)是其主要的毒素。因此,建立检测方法很有必要。试验研究了液相和飞行时间质谱联用技术检测BA。BA在ESI-Q-TOF中的主要特征离子有485.259 9,441.267 5和220.128 6。特征离子485.259 9可能是由[M-H^+]^-得到的,特征离子441.267 5可能是由[M-COO-H^+]^-得到的,特征离子220.128 6可能是由[M-COO-2H^+]^(2-)得到的。BA中的断裂的C—C单键与C==C双键相邻,断裂的原因可能是C==C双键与支链烃竞争电子导致C—C单键不稳定。试验采用甲醇作为提取溶剂振荡辅助提取,回收率高达78%以上,检测限为2μg/kg,定量限为5μg/kg。线性范围为5~100μg/kg,线性相关系数较好(r^2>0.99)。该方法的日内精密度和日间精密度分别为5.3%和10.4%。该方法快速、简单、稳定,可为政府监测市售食品是否被椰毒假单胞菌酵米面亚种污染提供依据。
Pseudomonas cocovenenans subsp.Farinofermantans was generally found in food stuff such as Tremella fuciformis,fermented rice flour,among others.BA is the main toxin of this pathogen,therefore,it is necessary to establish method for detecting BA.The fast,highly sensitive and reliable method of LC-ESI-Q-TOF for detecting BA was established in this paper.Characteristic ions of BA,such as 485.259 9（m/z）which presumably was ionization mode of[M-H^＋]^-and 441.267 5（m/z）which presumably was ionization mode of[M-COO-H^＋]^-and 220.128 6（m/z）which presumably was ionization mode of[M-COO-2H^＋]^2-,which was found in mass spectrogram.The ionization modes of BA were deduced through molecular ions and fragment ions.C—C single bond which was next to C==C double bond and linking to branch chain easily fractured,and the reason might be relating with strongly competing electrons between C==C double bond and branch chain.The method of LC-ESI-Q-TOF was used to detect BA in infant formula rice flour.Recovery reaching more than 78%in the way of that methanol was chosen as the extract solvent and extraction assisted by vortex oscillation.The limit of detection was 2μg/kg and the limit of quantity was 5μg/kg.The linearity range was from 5μg/kg to 100μg/kg,and high correlation coefficients（r^2〉0.99）of BA were obtained within its linear ranges（5-100μg/kg）by external standard method.The intra-and inter-day precisions（RSD）were 5.3%and 10.4%,and both of them were less than 15%.Above all this method of LC-ESI-Q-TOF was fast,simple,low cost,and high sensitive,and this method could provide tool for government monitoring BA in food sale in market.
作者
李红娜
袁飞
张辰陽
马文良
张峰
罗云敬
LI Hongna;YUAN Fei;ZHANG Chenyang;MA Wenliang;ZHANG Feng;LUO Yunjing(College of Life Science and Bioengineering,Beijing University of Technology（Beijing 100124;Institute of Food Safety,Chinese Academy of Inspection and Quarantine（Beijing 100176)
出处
《食品工业》
CAS
北大核心
2018年第7期319-323,共5页
The Food Industry
基金
公益性行业科研专项经费项目(201510038)
国家质检总局科技计划项目(2014IK084)
关键词
食品安全
分析化学
高分辨飞行时间质谱
米酵菌酸
food safety
analytical chemistry
high resolution time-of-flight mass spectrometry
bongkrekic acid
