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试样用乙腈匀浆移取,盐析离心后,取上清液经固相萃取柱净化,用乙腈-甲苯(3+1)洗脱农药及相关化学品,溶剂交换后用气相色谱-质谱仪检测,采用特征选择离子监测扫描模式(SIM),以各碎片的丰度比定性,标准样品定量离子内标法(环氧七氯)定量,进行方法的重复性和再现性验证,并确定了73种物质的定量限,可以作为食用农产品中农药残留及相关化学品残留的初筛方法。 相似文献
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气相色谱-质谱法测定脂肪酸组成鉴别地沟油的方法研究 总被引:1,自引:0,他引:1
建立了分析油脂样品中37种脂肪酸含量的气相色谱-质谱检测方法,通过对100多种植物油和20多种地沟油的37种脂肪酸含量的分析,总结出了根据37种脂肪酸含量鉴别地沟油的判定依据。低碳数饱和脂肪酸是地沟油与植物油差异较大的组分,但是应用气相色谱方法测定时无法对其进行准确的定性定量,从而无法根据低碳数饱和脂肪酸的组成进行是否地沟油判定。应用气相色谱-质谱方法,提高了方法的灵敏度,完善了根据脂肪酸组成判定地沟油的依据。应用该判定依据,对卫生部两次盲样进行判定,阳性准确率分别为100%和95%,阴性准确率分别为100%和90%,表明该判定依据是一种有效且准确率较高的鉴别地沟油的方法。 相似文献
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GC-MS法测定食品中甜蜜素定性定量分析的探讨 总被引:1,自引:0,他引:1
利用气相色谱-质谱联用技术的定性定量优势,对食品中甜蜜素的检测方法进行探讨。采用正己烷萃取食品中的甜蜜素,样品经过衍生化处理后,经HP-5毛细管柱(30 m×0.25 mm×0.25μm)分离。气相色谱测定甜蜜素,产生两个反应产物。经气质联用法发现峰1的质谱图与环己醇亚硝酸酯质谱图不匹配,峰2为环己醇。但在相同条件下,利用标样自建谱库,将待测样品与自建谱库中的甜蜜素标样检索比对,可完成甜蜜素的定性。由于峰1和峰2的面积和始终保持不变,所以可根据两峰面积和完成食品中甜蜜素的定量。本方法样品处理简单,定性准确,精密度高,适用于食品中甜蜜素的定性定量分析测定。 相似文献
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建立了凝胶渗透色谱(gpc)净化,气相色谱-质谱联用法(gc-ms)检测口鱼片中残留的禾草丹、呋喃硫威、扑草净三种农药残留.样品以乙腈为萃取溶剂,经凝胶渗透色谱(gpc)净化预处理,n-丙基乙二胺(psa)填料再净化,由气相色谱-质谱分时段选择离子监测技术进行测定与确证,外标法定量.3种农药在0.05~10mg/l范围内线性均良好;方法的灵敏度高,定量限(loq)均低于或等于0.01mg/kg;方法的准确度和精密度高,在0.01、0.005、01、05mg/kg4个添加水平下三种农药的回收率均在80%~100%之间,rsd≤8.4%.方法的最低检测限和添加回收率均符合农药残留分析的要求. 相似文献
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本研究建立了饲料产品中添加矿物质的定性和定量检测方法。该方法基于X射线衍射法(X-ray diffraction,XRD)鉴定饲料产品中添加矿物质种类,电感耦合等离子体发射光谱法(Inductively coupled plasma emission spectrometry,ICP)定量。样品置于马弗炉中灰化,用XRD分析灰分中矿物质成分;另取样品置于离心管中,加入(1+5, v/v)甲酸震荡提取。提取液通过离心净化后,取上层清液过0.22μm滤膜,用水定容后用ICP检测,外标法定量。最后,根据XRD结果推算矿物质的含量。本研究以添加碳酸钙、碳酸钙镁为例进行鉴别,结果表明,XRD检测低限可以鉴别0.1%的添加矿物质,ICP定量方法中Ca和Mg在0.1~10.0 mg/L浓度范围内呈良好线性,线性回归系数r2> 0.9997,空白样品加标回收率为86.7%~102%,相对标准偏差(RSD,n=6)为0.6%~1.8%。该方法准确、高效,前处理操作简单,可准确测定饲料产品中添加矿物质含量,并成功用于实际的样品测定和关税归类化验工作。 相似文献
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探讨了面粉中过氧化苯甲酰定性筛查的方法,依据GB/T18415-2001气相色谱法-1法中样品处理的第一步,依据提取液的颜色就可以把面粉分为三种情况:没有添加过氧化苯甲酰;可能添加了过氧化苯甲酰;一定添加了过氧化苯甲酰。再根据要求选择性的做定量试验,大大的减轻了工作量,节省了成本。 相似文献
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建立茶叶中18种农药残留的气相色谱-三重四级杆串联质谱(GC-MS/MS)检测方法。茶叶经过QuEChERS前处理,定容至1mL后,采用GC-MS/MS进行定性、定量检测分析。结果表明,18种农药在0.05~1.00 mg/kg质量浓度范围内线性关系良好,相关系数R2≥0.995;在空白茶叶基质中分别添加加标浓度为0.10 mg/kg、0.50 mg/kg、1.00 mg/kg;其加标平均回收率为89.34%~92.87%、精密度为5.015%~9.021%、检出限为0.0103~0.0254 mg/kg;各参数均符合GB/T 27404-2008《实验室质量控制范围食品理化检测》相应参数要求,表明该方法科学可靠;同时,该方法具有高效、灵敏、快速等特点。 相似文献
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The extent and magnitude of formalin adulteration in fish sold in domestic markets of Bangladesh: a literature review
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Sayeeda Rahman Md Anwarul Azim Majumder Rabiul Ahasan SM Moslehuddin Ahmed Palash Das Nuzhat Rahman 《International Journal of Consumer Studies》2016,40(2):152-159
Bangladesh has been suffering from rampant food adulteration for the last few decades. Dishonest businessmen use formalin illegally as preservative to prevent spoilage and increase shelf‐life of fish. Prolonged consumption of formalin adulterated fish may cause serious health hazards (i.e. cancers) which lead to increased morbidity and mortality. The aim of the review was to examine the extent and magnitude of illegal formalin treatment in fish sold in domestic markets of Bangladesh. A systematic review was conducted using conventional databases and non‐conventional approaches to identify the relevant studies. Out of nine studies, eight confirmed the presence of formalin in fish collected from the markets of four main cities. Large and imported fishes were found to be mainly affected. Formalin adulterated fish was reported in seven studies. The fish were tested using a locally developed kit, and the amount of formalin treated fish ranged between 0.5 and 50%. Two other studies used the spectrophotometric method and reported specific formalin levels. The study conducted in Dhaka found mean levels of formalin to be 402.35 mg/kg in imported fishes and 118.60 mg/kg in local fishes which were much higher than the WHO recommended levels. In another study conducted in Mymensingh, formalin levels ranged between 1.4 and 7.3 mg/kg in both marketed and freshly caught pond fishes. The use of accurate, simple, specific and sensitive techniques is therefore highly recommended. The government and other agencies should address the issue as a priority basis by formulating effective policies and programs to safeguard the health of the public. 相似文献
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Jean‐Franois Ouellet 《Canadian Journal of Administrative Sciences / Revue Canadienne des Sciences de l\u0027Administration》2007,24(2):107-119
Based on qualitative and quantitative surveys, I show that consumer responses toward a particular song and toward its performer(s) play distinct roles in explaining consumer choices to either buy or illegally download that song. The various types of consumer responses to songs and artists are first identified through qualitative research and then validated through exploratory and confirmatory factor analyses (CFA) of survey data. While consumer responses to music explain the need to reexperience and acquire the song, consumer responses to performers explain purchase over illegal downloading. Copyright © 2007 ASAC. Published by John Wiley & Sons, Ltd. 相似文献
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The efficiency of a market depends on the amount of information about products available to buyers. However, an information
goods market is not an efficient market because information goods are mostly experience goods. We suggest that illegal copying
can be an efficient information channel to account for the problem. We also suggest that partially enforced copyright protection
may encourage the competition between the original information goods and illegally copied goods that benefits not only customers
but also producers. 相似文献
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