目的测定食用油等油中的呋喃含量。方法将5 g油样密封于(540±5)mL瓶中,加入一定量呋喃(X),于65℃水浴加热1 h后测定其呋喃(Y)含量。选择离子流动管质谱(selected ion flow tube mass spectrometry,SIFT/MS)方法,以NO+为初始离子,...目的测定食用油等油中的呋喃含量。方法将5 g油样密封于(540±5)mL瓶中,加入一定量呋喃(X),于65℃水浴加热1 h后测定其呋喃(Y)含量。选择离子流动管质谱(selected ion flow tube mass spectrometry,SIFT/MS)方法,以NO+为初始离子,测定油样密封瓶顶空中呋喃浓度,再据呋喃标准曲线定量密封瓶中油样的呋喃含量。结果所得标准曲线为:Y=29.55X+1.11(r^2=0.9867,n=6),其检测限和定量限分别为0.052 ng/g和0.063 ng/g。利用该标准曲线测定多种油,其中废弃餐用油(即各种类型的地沟油、煎炸老油等)呋喃含量为4.37~17.83 ng/g;大豆油、花生油、两种菜籽油、茶油、葵花油的呋喃含量均小于1 ng/g;两种冷榨橄榄油的呋喃含量分别为1.19和4.39 ng/g。结论该法可方便、快速、准确地测定油样中呋喃的含量,呋喃可以作为鉴伪食用油和废弃餐用油的特征性指标。展开更多
The organic acids in Hawthorn fruits from Henan Huixian and Tongbai Mountain were determined by gas chromatography-mass spectrometry method and 23 organic acids were identified.The main organic acids in Hawthorn fruit...The organic acids in Hawthorn fruits from Henan Huixian and Tongbai Mountain were determined by gas chromatography-mass spectrometry method and 23 organic acids were identified.The main organic acids in Hawthorn fruit were linoleic acid,oleic acid,linolenic acid,Citric acid,and hexadecanoic acid.There are almost the same kinds of organic acids in the two samples,but the contents of the organic acids in the two samples were very different.The contents of 8 main organic acids in Hawthorn fruits were determined by GC-MS selected ion monitoring(SIM)using internal standard curve method.The added standard recovery of the method was in the range of 92.8～103.2%,the relative standard deviations(RSD)were less than 3.5%,the correlation coefficients were more than 0.999 and the detection limits were in the range of 1.0～2.5 mg/L.展开更多
文摘The organic acids in Hawthorn fruits from Henan Huixian and Tongbai Mountain were determined by gas chromatography-mass spectrometry method and 23 organic acids were identified.The main organic acids in Hawthorn fruit were linoleic acid,oleic acid,linolenic acid,Citric acid,and hexadecanoic acid.There are almost the same kinds of organic acids in the two samples,but the contents of the organic acids in the two samples were very different.The contents of 8 main organic acids in Hawthorn fruits were determined by GC-MS selected ion monitoring(SIM)using internal standard curve method.The added standard recovery of the method was in the range of 92.8～103.2%,the relative standard deviations(RSD)were less than 3.5%,the correlation coefficients were more than 0.999 and the detection limits were in the range of 1.0～2.5 mg/L.
