保健食品中总黄酮含量的分光光度测定法

保健食品中总黄酮含量测定，目前国家无标准方法，结合工作实际，本文对保健食品中总黄酮含量测定方法进行了探讨。报告如下。     

保健食品中总蒽醌的测定

目的：建立具有可靠性、可操作性、适用性强的保健食品中总蒽醌测定法。方法：以甲醇为提取溶剂,样品经酸解、氧化处理后用分光光度法测定。结果：回收率为83.6%-91.5%,精密度RSD〈10%。结论：已应用本方法检测6种含蒽醌的保健食品产品,方法操作简便,重现性好。     

分光光度法测定保健食品中总黄酮的含量

[目的]建立一种测定保健食品中总黄酮含量的简便、快速的分析方法。[方法]以芦丁为标准品,在波长360 nm处,用分光光度法测定保健食品中总黄酮的含量。[结果]芦丁标准品在0.0--25.0μg/ml范围内,其浓度与吸光度值呈良好线性关系（r=0.9999）。以乙醚代替苯作为洗脱剂,测定样品的相对标准偏差2.32%--5.67%,回收率84.72%--90.39%。[结论]该方法重现性及稳定性好,线性范围宽,特别是减少了有毒试剂对检测人员的危害及对环境的污染,可用于保健食品中总黄酮含量的测定。     

紫外分光光度法测定保健食品中总黄酮的方法改进

目的:改进紫外分光光度法测定保健食品中总黄酮。方法:以无水乙醇提取保健食品中的总黄酮,经聚酰胺小柱吸附后,以乙醚除杂,经甲醇洗脱黄酮,定容后紫外分光光度比色测定总黄酮含量,外标法定量。结果:该法线性范围为50μg~250μg,回收率为85%~90%,相对标准偏差<5%,最低定量检出限为5μg。结论:该方法具有准确、灵敏、快速、简便、对操作者毒害小等特点,可以用于实际样品的测定工作。     

巯基棉分离富集催化动力学分光光度法测定痕量硒(Ⅳ)

基于硒能催化天青Ⅱ氧化硫离子的反应，建立了新的高灵敏测定痕量硒的催化动力学分析法，并结合改进的巯基棉分离富集法进行了水样中硒的测定。     

香波中硒测定方法的探讨

香波中硒测定方法的探讨山东省卫生防疫站（济南２５００１４）张炳坤，李风霞，曹艳萍，王国玲硒是人体必需的营养元素。体内硒含量过低能引起营养不良导致心肌病变，过高则引起硒中毒．洗发香波中二硫化硒的限用量为０．５％［１］．本文对香波中硒（ＩＶ）的测定方法进...     

保健食品中D-氨基葡萄糖盐酸盐含量的检测

[目的]用分光光度法测定保健食品中的D-氨基葡萄糖盐酸盐。[方法]样品在碱性条件下与乙酰丙酮缩合形成2-甲基-二乙酰吡咯衍生物,再与对-二甲胺基苯甲醛(PDABA)在酸性条件下结合呈现红色,在520nm测定其吸收值与标准比较定量。[结果]在0～45.3μg/ml的范围内,D-氨基葡萄糖盐酸盐的浓度与吸光度呈良好的线性关系(r=0.9996),RSD=0.81%,平均回收率101.38%,方法检出限2.32μg/ml。[结论]此方法准确、简便,适用于保健食品中的D-氨基葡萄糖盐酸盐含量的检测。     

荧光分光光度法测定母乳中硒

硒是人体必需的微量元素之一 ,对人类的成长和发育起着重要作用 [1 - 2 ]。硒缺乏时使人体免疫力降低 ,多种疾病的发病率升高 [1 - 2 ]。过量硒又能引起硒中毒 [1 ]。母乳中的硒含量国内未见报道 ,国外报道亦少。作者以荧光分光光度法测定了 5 6份母乳中的硒含量 ,为母乳喂养的优越性提供了新的证据。1　测定方法1.1　原理　样品经混合酸消化后 ,硒化合物转变成四价无机硒 ,与 2 ,3-二氨基萘 (简称 DAN)反应生成 4,5 -苯并苤硒脑绿色荧光物质 ,能为环己烷萃取 ,其荧光强度与硒的浓度在一定条件下成正比。1.2　主要仪器与试剂　 96 0型荧光…     

荧光分光光度法测定母乳中硒

对母乳中硒含量的测定国内未见报道,国外报道亦少见.2,3-二氨基萘(简称DAN)荧光分光光度法测定食品中硒具有灵敏度高等优点,但消化样品时常用到去硒硫酸,较麻烦.本文提出硝酸-高氯酸中低温湿法消解样品,以合理简化的DAN荧光分光光度法测定母乳中硒含量,相对标准差为2.9%,加标回收率为92%～99%,结果满意.现介绍如下.     

保健食品中砷和硒同时测定方法的研究

目的：建立同时测定保健品中砷和硒的方法。方法：湿法消解样品后用双道氢化物发生原子荧光光谱法同时测定砷和硒。结果：方法简单，准确，砷回收率为91．6％～100．7％，相对标准差0．43％～1．98％；硒回收率为90．8％～101.4％，相对标准差为0．46％～1．93％。结论：保健食品经湿法消解后，砷和硒可用双道氢化物发生原子荧光光谱法同时测定。     

电感耦合等离子体质谱法测定保健食品中的硒

目的建立电感耦合等离子体质谱（ICP—MS）测定富硒保健食品中硒元素的方法。方法以市售富硒保健食品为研究对象,样品经高压微波消解处理后,应用ICP—MS测定其中硒元素含量。结果本研究方法测定的硒元素的标准曲线线性相关系数为0．9999;加标回收率范围在99．40％-100．15％;检出限为0．078μg／L;相对标准偏差范围在0．91％～2．65％。结论该方法具有快速、简便、灵敏、准确的优点,适用于保健食品中硒元素的测定。     

Observational Conditioning of Food Valence in Humans

It has been suggested that the observation of a model consuming a food (CS) and facially expressing either to like or to dislike (US») the food, may be a sufficient condition to bring about a change in the valence of the food for the observer. Unfortunately, up to now this hypothesis has not been investigated in a straightforward manner. In this study, during acquisition, children consumed a series of evaluatively neutral colored and flavored drinks, while simultaneously they watched a videotaped model synchronically drinking identical drinks and facially expressing his evaluation (neutral or dislike) of the liquids. In one condition, the presence of a particular flavor in the drinks was designated to function as the CS+ or the CS−, whereas in the other condition it was the color of the drinks which was the critical CS+ or CS−. Next, the children evaluated a series of drinks containing the critical CSs. A clear evaluative learning effect was obtained when the flavor but not when the color of the drinks was systematically paired with the model's facial expression of dislike. Moreover, the flavor conditioning effect was dependent on the presence in the test drinks of the local context cues (c.q. the colors of the drinks) which were used during acquisition. Finally a double dissociation was observed between explicit beliefs and the “evaluative knowledge” expressed in the ratings of the drinks, in that none of the children in the CS=Flavor groups evidenced any explicit knowledge about the crucial CS-US» contingency but showed evaluative conditioning, whereas the majority of the children in CS=Color groups were aware of the CS-US» relation but failed to demonstrate an evaluative CS+/CS− differentiation.     

食品中硒的分析进展

硒是人体必需的微量元素之一 ,具有多方面的生理功能。食物是人体硒摄入的主要来源 ,食物中硒的含量及形态与人体的健康关系密切。概述了近年来食品中硒含量测定方法和形态分析现状 ,指出硒形态分析是今后的发展趋势 ,为提取食物中活性硒组分开发第三代富硒功能食品奠定基础。     

上海地区79种动物性食物的硒含量分析

<正>近年对硒的生物化学与营养学研究日趋深入，进一步证实了硒对人体营养的重要性，国内外已发表的食物硒含量的论文数量不断增加，这为评价群体的硒摄入量和选择     

微量元素硒与人体健康

微量元素硒与人体健康密切相关,文章引导人们进一步认识硒元素生理功能,树立科学补硒新观念,正确理解硒元素的二重性,走出盲目补硒的误区,找到适合自己补硒的方案。     

富硒食品中微量元素分析

建立电感耦合等离子体质谱法(ICP-MS)测定富硒食品中多种微量元素,选取富硒食品和保健品,使用微波消解法消化样品,ICP-MS同时测定铝、铬、锰、铁、镍、铜、锌、砷、硒、镉、锡、锑、铊、铅含量。方法表明在较大浓度范围内(0～400μg/L)线性关系良好,配合使用微波消解,有效降低样品损耗,对三个不同加标浓度测定回收率较高,方法简单易行,准确度高。比较富硒大米和普通大米发现硒元素、重金属及其它有益元素元素含量存在差异。天然富硒食品中,小米和紫薯硒含量较高,表明这两种农作物具有较强的富集能力。     

青海省人群膳食硒摄入量与血硒含量关系的调查分析

采用分怪整群随机抽样方式，在占青海省总人口７５．５６％的２３个县中，开展人群膳食硒摄入量调查，并进行食物硒与血硒关系的分析。结果表明，全省人群膳食硒摄入量均值为２５．９０μｇ／ｌ日，是杨光圻提出“膳食硒适宜量５０μｇ／日”的５１．８０％，是“生理需要量４０μｇ／日”的６４．７５％。     

食品中无机砷及其价态测定

目的应用氢化物发生-原子荧光分析技术测定食品中总无机砷、三价砷[As3 ]和五价砷[As5 ].方法6 mol/LHCl提取食品中无机砷,在2 mol/L HCl条件下测定总无机砷,再利用在强酸条件下,甲苯可以定量将无机砷中As3 萃取到有机相中从而达到分离As3 和As5 ,最后分别测定不同价态的砷.结果经过多次实验,该方法样品回收率:无机砷为85%～105%,三价砷为85%～110%,五价砷为90%～110%;样品的相对标准偏差:三价砷为7.56%,无机砷为5.53%.结论此法可以满足各类食品的无机砷的测定及价态分析,并且分析快速、灵敏度高、干扰少.     

Health Representations,Perceived Valence,and Concept Associations for Symbols as Food Cues: A Mixed-Methods Approach

Researchers have experimented with a range of point-of-purchase (PoP) interventions in supermarkets, restaurants, and cafeterias. In general, these interventions have employed written materials. This research tested symbols to visually summarize information about the (un)healthiness of food. Study one explored health representations and valence associated with the image of a heart, a bathroom scale, and a running shoe using qualitative field interviews (N = 1200). Study two explored accessibility of a priori concept associations for two of those images, stratified by valence, in a computerized response latency task (N = 40). Study one indicted that the heart was best linked to its intended theme “heart health.” Concerning valence, the heart was seen as both positive and negative whereas the scale was less likely to be viewed as positive relative to the running shoe. In study two, the heart was linked to five of the six a priori concepts and there was evidence that three of these were more accessible. Overall, the heart was better linked to positive poles than negative ones. A heart symbol may be useful to prompt heart healthy choices at the PoP. There was evidence that a scale may bias choice away from undesirable foods.     

Selenium as a Health Hazard

Elemental selenium appears to be without action on the humanbody, whether applied externally or taken internally. Selenium dioxide is an irritant of the skin and mucous membranes. Selenious acid is a corrosive. When selenium dioxide and selenious acid are handled with fullprecautions and due care, the danger is minimal. There is no evidence that exposure to selenium or its compoundsproduces long-term effects on the human body.