Identification of Irradiated Protein-rich Food by Dissociative Tyrosine

建立了高效液相色谱-游离酪氨酸法鉴定高蛋白含量辐照食品的方法。向经过辐照的高蛋白含量样品中加入0.1 MOl/l HCl,使细胞裂解并释放出游离酪氨酸,离心除去细胞碎片后,向上清液中加入80%丙酮并在-20℃下冰冻沉淀除去大部分蛋白,样品中的酪氨酸与三氟乙酸形成离子对后经C18色谱柱分离。在100~1 500μg/l质量浓度范围内,邻酪氨酸和间酪氨酸均具有良好线性,方法的回收率为61%~116%,定量下限(S/n≥10)为10μg/l。该法避免了蛋白质的水解,具有操作简便、测定准确等优点,能很好地区分未经辐照与经5 kgy以上剂量辐照的食品。A novel method was presented for identification of irradiated protein-rich food by HPLC with dissociative tyrosine.The procedure involved the homogenization of fresh sample with 0.1 mol/L HCl,followed by centrifugation to remove the cell debris and the solvent precipitation of protein with acetone at-20 ℃,then the tyrosine was separated by forming ion pair with trifluoroacetic acid on a C18 column.The average recoveries of the drugs ranged from 61% to 116% at the spiked levels of 100-800 μg/L.The method is simple and double-quick,and could be efficiently identified food sample irradiated at a dose of 5 kGy or above.国家质量监督检验检疫总局科研计划资助项目(2009IK183

Determination of fungicide anilinopyrimidine residues in food by series solid phase extraction-high performance liquid chromatography-tandem mass spectrometry

建立了食品中嘧啶胺类杀菌剂嘧霉胺、嘧菌胺及嘧菌环胺残留的串联固相萃取-液相色谱-串联质谱(HPlC-MS/MS)检测方法。胡萝卜、辣椒等样品经乙酸乙酯提取,石墨化炭黑-弗罗里硅藻土串联固相萃取柱(EnVI-CArb-flOrISIl SPE)净化后,在HPlC-MS/MS仪上进行检测分析,采用外标法定量。质谱分析采用电喷雾电离,正离子扫描,多反应监测模式。结果表明,柱净化后无明显的基质效应,嘧霉胺、嘧菌胺和嘧菌环胺在1~20μg/l内相关系数可达0.999 0以上,具有良好的线性关系;每种杀菌剂选择两个离子对,其中一组用于定量:嘧霉胺M/z 200.1/107.1,嘧菌胺M/z 224.0/106.0及嘧菌环胺M/z 226.0/108.1;另一组用于确证:嘧霉胺M/z 200.1/183.1,嘧菌胺M/z 224.0/131.1和嘧菌环胺M/z 226.0/133.1。样品中添加0.1、0.5、1.0μg/kg的标准品,其回收率为73.2%~98.7%,相对标准偏差(n=10)小于10%;嘧霉胺、嘧菌胺、嘧菌环胺的检出限(信噪比(S/n)=3)均为0.03μg/kg;嘧霉胺、嘧菌胺、嘧菌环胺的定量限(S/n=10)均为0.1μg/kg。实验结果表明,该方法提取效果好,具有良好的灵敏度、回收率和重复性。A high performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS) method was established for the determination of fungicide anilinopyrimidine residues including pyrimethanil,mepanipyrim,and cyprodinil in foodstuffs with series solid phase extraction(SPE).The food sample was first extracted with ethyl acetate,and then purified by an ENVI-Carb cartridge and a Florisil SPE cartridge.The analytes were determined by HPLC-MS/MS and quantified by external standard method.The mass spectrometric detection was operated with electrospray in positive ionization mode and the fungicide anilinopyrimidines were identified in multiple reaction monitoring(MRM) mode.The linear range of the method was 1-20 μg/L,with the correlation coefficient(r2) over 0.9990.The transitions of the precursor ions to two selected product ions were involved,in which one group for quantification were m/z 200.1/107.1 for pyrimethanil,m/z 224.0/106.0 for mepanipyrim and m/z 226.0/108.1 for cyprodinil,and the other group for identification were m/z 200.1/183.1 for pyrimethanil,m/z 224.0/131.1 for mepanipyrim and m/z 226.0/133.1 for cyprodinil,respectively.No significant matrix effect was found for spiked samples after the purification.The recoveries of the fungicide anilinopyrimidines spiked in food samples were 73.2%-98.7% at the spiked levels of 0.1,0.5,1.0 μg/kg.The relative standard deviations(RSDs) were less than 10%.The limits of detection(LODs) and limits of quantification(LOQs) were 0.03 μg/kg and 0.1 μg/kg for the three fungicides,respectively.The results showed that the proposed method is sensitive and accurate for the determination of fungicide anilinopyrimidines in foodstuffs.The method should be applicable for routine analysis of pyrimethanil,mepanipyrim,cyprodinil residues in foodstuffs.厦门市科技计划项目(3502Z20092009、3502Z20102013);国家质检总局科技计划项目(2010IK192

Determination of Dithiocarbamates in Foodstuffs by LC-MS/MS

通过优化质谱、液相色谱和萃取缓冲液等条件,建立了一种简单、快速、灵敏测定食品中二硫代氨基甲酸酯的方法。在优化条件下,代森锌(EbdC)、丙森锌(PbdC)的线性范围为2~100μg/l,相关系数均不小于0.997。在花椰菜、萝卜和豌豆中EbdC和PbdC的检出限(S/n>3)为2μg/kg;萝卜和豌豆中Eb-dC和PbdC的定量下限(S/n>10)为10μg/kg,而花椰菜中EbdC和PbdC的定量下限(S/n>10)为15μg/kg。在花椰菜、萝卜和豌豆基质中加标5~100μg/kg的EbdC和PbdC时,测定加标回收率为83%~96%,相对标准偏差为4.4%~10.5%,方法可满足定量分析的要求。A simple,fast and sensitive method was developed for the determination of dithiocarbamates,including tiezene(EBDC) and pestanal(PBDC),by optimizing the parameters of LC-MS/MS and extraction buffer.Under the optimized conditions,the calibration curves of EBDC and PBDC were linear in the range of 2-100 μg/L with correlation coefficients not less than 0.997.The limits of detection(LODs,S/N>3) of EBDC and PBDC were 2 μg/kg for cauliflower,turnip and pea,and the limits of quantitation(LOQs,S/N>10) of EBDC and PBDC were 10 μg/kg for turnip and pea,and 15 μg/kg for cauliflower.The recoveries in cauliflower,turnip and pea samples at spiked concentration levels of 5-100 μg/kg ranged from 83% to 96% with relative standard deviations(RSDs) of 4.4%-10.5%.The method could meet the requirement for the analysis of dithiocarbamates in foodstuffs.厦门市科技计划项目(3502Z20092009;3502Z20102013); 国家质检总局科技计划项目(2010IK162;2010IK192

【資料紹介】花岡大学宛前登志夫書簡（１）：一九五〇年一月一九五五年九月、「前登志晃｣時代の書簡

departmental bulletin pape

Identification of True and Fake Cubilose Using a ~1H-NMR-based Method

燕窝是一种高级保健品,主要成分之一是唾液酸糖蛋白.燕窝经过水解作用后,可获得唾液酸等特征性小分子水解产物.因现有的针对真假燕窝的检测方法仍存在较多的不足之处,本文以6种真品燕窝和4种假燕窝作为标准样品,通过测定核磁共振一维氢谱(1 H-nMr)的方法,以燕窝水解产物唾液酸中微量特有组分的特征峰为鉴定标准,得到能显著区分真假燕窝的指纹图谱;结合使用模式识别主成分分析法(PCA)处理核磁共振数据,确定了真燕窝的主成分正交范围,并通过盲测的方法验证了上述方法的准确性及高效性.至此,本文建立了一种基于1 H-nMr指纹图谱鉴定燕窝真伪的检测方法,结合PCA验证,可以简单、快速、准确地区分真假燕窝.Cubilose,of which saliva acid glycoprotein is the main composition,is a kind of advanced health products.In this study,a method was established based on 1 H-nuclear magnetic resonance(1 H-NMR)fingerprinting spectra to identify true and fake cubilose.Samples from six types of true cubilose and four fake ones were tested,using the peaks of characteristic components in sialic acids from salivary glycoproteins hydrolyzed from cubilose.1 H-NMR fingerprinting spectra were recorded and principal components analysis(PCA)was conducted to analyze the data.Both 1 H-NMR fingerprinting spectra and PCA showed that different samples of true cubilose had a high degree of similarity,while the fake ones were very different.Then we verified the veracity and efficiency of1 H-NMR-based method by blind test.Thus,the 1 H-NMR-based method can effectively distinguish true and fake cubilose.国家质检总局科技项目(2014IK096); 福建省社会发展重点项目(2013Y0078); 厦门市科技计划项目(3502Z20133005