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应用反相高效液相色谱法快速测定食品中的L-抗坏血酸和D-异抗坏血酸 总被引:1,自引:0,他引:1
本文报道了以反相高压液相色谱测定食品中L-抗坏血酸和D-异抗坏血酸的方法。样品经捣碎、超声波振荡、离心、过滤后,在ODSC-18 4.6×250mm反相柱中,用0.001mol/l正辛胺及0.02mol/l醋酸铵(pH5.4),水溶液作为流动相,经分离后在波长265nm下检测定量,食品中含5μg/g的L-广抗坏血酸及g-5ug/gD-异抗坏血酸可被完全分离并定量测定。L-抗坏血酸及D-异抗坏血酸回收率分别为99.9%和98.7%,变异系数分别为1.78和4.44%。 相似文献
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目的 建立食品中过氧化氢含量的高压液相色谱检测方法。方法 用水提取样品中过氧化氢, 用乙腈做萃取液和流动相, 在1 mL/min流速下, 用Venusil HILIC 色谱柱(250 mm×4.6 mm, 5 μm, 100 ?)不经过衍生化, 直接通过紫外检测器检测食品中的过氧化氢。结果 过氧化氢的检出限为0.6 μg/mL, 定量限为2 μg/mL。对实际样品进行检测时, 平均回收率R≥30%, RSD≤7%。结论 该方法准确、灵敏、精密度高, 可用于食品中过氧化氢的测定。 相似文献
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婴幼儿配方食品中叶黄素的提取及测定 总被引:1,自引:0,他引:1
比较婴幼儿配方食品中叶黄素的3种提取方法:氢氧化钾皂化法、丙酮提取法和正己烷提取法,从中得出最佳提取方法为正己烷萃取法。选用色谱柱YMC Carotenoid(4.6mm×250mm,5μm)以甲醇、甲基叔丁基醚为流动相进行梯度洗脱,流速为1mL/min,于445nm波长处测定婴幼儿配方食品中叶黄素的含量。该方法操作简便,提取效率高(平均回收率为95.4%),重现性好(RSD为0.93%),检出限为2μg/100g,可以准确的测定婴幼儿配方食品中叶黄素的含量。 相似文献
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高效液相色谱法测定枣叶中酸枣仁皂苷B的含量 总被引:1,自引:0,他引:1
建立了一种测定枣叶中酸枣仁皂苷B含量的高效液相色谱分析方法,色谱条件为:色谱柱Hypersil BDS C18(4.6 mm×200 mm,5μm);流动相为乙腈:水(35:65,v/v),加入甲酸0.05%;流速为0.8 mL/min;柱温30℃;检测波长204 nm。结果表明:酸枣仁皂苷B在20~1000μg/m L范围内具有良好的线性关系(r2=0.9999),平均加标回收率为100.1%,最低检出限1.1μg/mL。采用开发的高效液相色谱法对14个品种的大枣及酸枣的幼叶中酸枣仁皂苷B的含量进行了测定,其含量在0.91~2.67 mg/g之间。 相似文献
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高效液相色谱法测定油菜籽中维生素E含量 总被引:2,自引:1,他引:1
建立了油菜籽中VE的高效液相色谱测定方法,比较了样品处理方法对测定油菜籽中Ⅶ的影响.采用硅胶柱色谱柱,流动相为正己烷:乙醚=93:7(v/v),流速为1.2mL/min,荧光检测器激发波为290 nm、发射波长为330nm.线性范围为10~60μg/mL,平均回收率为107%,变异系数为1.1%,正己烷溶剂浸提法比皂化方法好. 相似文献
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为建立高效液相色谱法同时检测饮料食品中4种高倍甜味剂的方法,样品经水溶后超声波振荡提取,Inertsil C18色谱柱(250mm×4.6mm;5μm)分离,甲醇:水(43:57)(v/v)流动相洗脱,流速:1mL/min;柱温:25℃;蒸发光散射检测器检测器条件:漂移管温度:85℃;气体压力:25psi;雾化器温度:25.2℃.进样量20μL.结果表明:安赛蜜、甜蜜素、三氯蔗糖和阿斯巴甜进样量0.110mg/mL的范围线性良好,相关系数分别为相关系数均为0.9947、0.9993、0.9998、0.9976.检出限分别为8.8μg/mL、4.0μg/mL、3.2μg/mL、1.4μg/mL:样品平均回收率在98.30%99.00%之间,RSD%<1.63%.本方法可同时对三氯蔗糖、甜蜜素、安塞蜜和阿斯巴甜等四种高倍甜味剂的分离与检测,该方法灵敏度高,重复性好,为快速检测食品中的高倍甜味剂提供了技术支持. 相似文献
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目的 建立准确可靠的高效液相色谱测定食品中苏丹红Ⅰ~Ⅳ的方法。方法 用乙腈提取样品中的苏丹红,经漩涡超声离心后,将乙腈层倾倒出;用乙腈重复提取,合并乙腈层,旋转蒸发至干。用乙腈转移至凝胶色谱进样小瓶,通过凝胶色谱的净化,用液相色谱进行检测。其中凝胶色谱柱为Bio-BeadsTM S-X3 Beads,液相色谱柱为Waters C18 (4.6mm × 150mm × 5μm),液相色谱流动相为乙腈-水(v/v,90:10)。结果 4种苏丹红染料的检出限均能达到10 μg/kg,满足国标要求。标准加入量为0.16μg/mL浓度时辣椒粉的回收率为92.5~97.5、辣椒酱的回收率为83.8~87.5、香肠的回收率为82.5~98.8,相关系数0.9995以上,且重复性良好。结论 高效液相色谱法可以测定食品中苏丹红Ⅰ~Ⅳ,适用于批量样品的检测。 相似文献
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心脑血管疾病、肿瘤、糖尿病、神经系统疾病、自身免疫等疾病严重危害着人类的生命和健康,并消耗着大量医疗资源。事实上,很多疾病发生和发展的背后都伴随着炎症反应,炎症是众多疾病的病理基础,甚至是导致这些疾病的诱因。炎症本身是机体的防御性反应,但过度的炎症反应和长期慢性炎症会损害机体的稳态。炎症的调节和控制由炎症介质介导,花生四烯酸(arachidonic acid,AA)、二十二碳六烯酸(docosahexaenoic acid,DHA)和二十碳五烯酸(eicosapentaenoic acid,EPA)等长链多不饱和脂肪酸(10ng-chain polyunsaturated fatty acids,LC-PUFAs)的衍生物是一类重要的调控炎症的介质。炎性细胞间的交流和细胞内信号传递与LC-PUFAs有关。AA经环氧酶和脂氧合酶合成的类二十烷酸主要起促炎作用,但有的也有抗炎作用。DHA和EPA在体内起抗炎作用,由它们合成的消退素(resolvins,Rvs)和保护素(protectin,PD)是重要的抗炎活性物质。DHA和EPA还可以干扰炎性细胞内信号传导途径来抑制炎症反应。本文从炎症与疾病的关系、LC-PUFAs的衍生物及其促炎和抗炎机制等方面综述了AA、DHA和EPA在炎症中的作用。 相似文献
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Obesity has become a prevailing epidemic throughout the globe. Effective therapies for obesity become attracting. Food components with beneficial effects on "weight loss" have caught increasing attentions. Conjugated linoleic acid (CLA), docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA) belong to different families of polyunsaturated fatty acids (PUFA). However, they have similar effects on alleviating obesity and/or preventing from obesity. They influence the balance between energy intake and expenditure; and reduce body weight and/or fat deposition in animal models, but show little effect in healthy human subjects. They inhibit key enzymes responsible for lipid synthesis, such as fatty acid synthase and stearoyl-CoA desaturase-1, enhance lipid oxidation and thermogenesis, and prevent free fatty acids from entering adipocytes for lipogenesis. PUFA also exert suppressive effects on several key factors involved in adipocyte differentiation and fat storage. Despite their similar effects and shared mechanisms, they display differences in the regulation of lipid metabolism. Moreover, DHA and EPA exhibit "anti-obesity" effect as well as improving insulin sensitivity, while CLA induces insulin resistance and fatty liver in most cases. A deeper and more detailed investigation into the complex network of anti-obesity regulatory pathways by different PUFA will improve our understanding of the mechanisms of body weight control and reduce the prevalence of obesity. 相似文献
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气相色谱法同时快速测定食品中丙酸、山梨酸、苯甲酸及脱氢乙酸 总被引:1,自引:0,他引:1
通过液液萃取净化样品研究,建立了食品中丙酸、山梨酸、苯甲酸、脱氢乙酸及其盐含量气相色谱同时快速测定方法,适用于固体非酯(脂)类食品的检测。结果表明:丙酸的回收率在85.1%~91.3%之间,其余3种防腐剂的回收率均在95.2%~99.4%之间;实验室内变异系数(CV,n=6)最大值≤4.7%,4种防腐剂检出限均在0.002 g/kg以下。4种目标物在有杂质干扰时,可用不同的极性毛细管柱做进一步的确认。本方法具有适用范围广、检测效率高、重现性好、准确度高、检出限低的特点,推广应用对我国食品安全的监督检验具有重要的意义。 相似文献
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Previous research found that docosahexaenoic acid (C22:6n-3) was a component of fish oil that promotes trans-C18:1 accumulation in ruminal cultures when incubated with linoleic acid. The objective of this study was to determine if eicosatrienoic acid (C20:3n-3) and docosatrienoic acid (C22:3n-3), n-3 fatty acids in fish oil, promote accumulation of trans-C18:1, vaccenic acid (VA) in particular, using cultures of mixed ruminal microorganisms. Treatments consisted of control, control plus 5 mg of C20:3n-3 (ETA), control plus 5 mg of C22:3n-3 (DTA), control plus 15 mg of linoleic acid (LA), control plus 5 mg of C20:3n-3 and 15 mg of linoleic acid (ETALA), and control plus 5 mg of C22:3n-3 and 15 mg of linoleic acid (DTALA). Treatments were incubated in triplicate in 125-mL flasks, and 5 mL of culture contents was taken at 0 and 24 h for fatty acid analysis by gas-liquid chromatography. After 24 h of incubation, the concentrations of trans-C18:1 (0.87, 0.88, and 0.99 mg/culture), and VA (0.52, 0.56, and 0.62 mg/culture) were similar for the control, ETA, and DTA cultures, respectively. The concentrations of trans-C18:1 (5.51, 5.41, and 5.36 mg/culture), and VA (4.78, 4.62, and 4.59 mg/culture) were also similar between LA, ETALA, and DTALA cultures, respectively. These data suggest that C20:3n-3 and C22:3n-3 are not the active components in fish oil that promote VA accumulation when incubated with linoleic acid. 相似文献
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以蔗糖、辛酸为原料,杂多酸为催化剂合成辛酸蔗糖酯。用L16(45)正交设计优化实验,高效液相色谱法分析反应液组成。考察了催化剂种类和用量、反应温度、原料配比、反应时间等因素对辛酸蔗糖酯产率的影响,发现以二甲基亚砜为溶剂、蔗糖与辛酸摩尔比1∶9、磷钨酸用量为蔗糖质量的2.0%、110℃反应时间6h,蔗糖转化率达60%,产物产要是二酯。动力学研究发现,蔗糖反应级数为一级,反应表观速率常数为0.0059min-1(90℃)、0.0117min-1(110℃),反应表观活化能Ea=39.57kJ/mol。 相似文献
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目的通过优化鱼油中二十碳五烯酸(eicosapentaenoic acid,EPA)、二十二碳六烯酸(docosahexaenoic acid,DHA)和二十二碳五烯酸(docosapentaenoic acid,DPA)的测定条件,建立鱼油中EPA、DHA和DPA气相色谱定量检测分析方法。方法采用正己烷处理样品,经色谱柱(Agilent,Elite-WAX,30 m×0.25 mm,0.25μm)分离鱼油中的EPA、DHA、DPA甲酯标准品,并进行定量检测。结果 EPA浓度在0.36~3.6 mg/m L、DHA浓度在0.37~3.7 mg/m L、DPA浓度在0.16~1.62 mg/m L的范围内与峰面积的线性良好,相关系数r0.999。在80%、100%、120%添加水平下,EPA、DHA和DPA的检出限分别为0.01%、0.03%、0.009%,EPA、DHA和DPA的回收率分别为96.2%、96.4%、95.7%。结论气相色谱法灵敏度高、准确、重现性好,适用于鱼油中EPA、DHA和DPA的含量测定。 相似文献
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目的:建立一种生活饮用水中乙二胺四乙酸(EDTA)和次氮基三乙酸(NTA)的高效液相色谱测定方法。方法:样品与三氯化铁络合后,以甲醇和0.2 mmol/L四丁基溴化铵—磷酸缓冲溶液(pH 2.5)为流动相,梯度洗脱后经Thermo-C18(4.6 mm×250 mm)色谱柱分离,DAD检测器检测,外标法定量。结果:EDTA和NTA在0.1~2.0 mg/L质量浓度范围内与色谱峰面积线性关系良好,相关系数分别为0.999 5,0.999 2;两者的检出限为0.05 mg/L,定量限为0.1 mg/L,平均加标回收率为93.5%~111.4%,相对标准偏差(RSD)为3.63%~7.39%。结论:该方法操作简便,重复性好,灵敏度高,具有较好的实用性。 相似文献
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高效液相色谱法检测贝类中的乳酸和琥珀酸 总被引:1,自引:0,他引:1
研究探讨利用高效液相色谱测定贝类中乳酸和琥珀酸的样品处理方法和测定方法,结果显示:与乙醇沉淀法、国标法相比,流动相提取法更适合作为样品的提取方法,在检测条件中,流动相为pH2.5的2.0%NH4H2PO4,流速在1.0mL/min,波长为205nm为最优条件。此方法具有较好的线性、较高的准确度和精密度,加标实验回收率为94.0%~99.9%,相对标准偏差为0.09%~0.14%。也测定了两种贝类中乳酸和琥珀酸的含量。 相似文献
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芥酸常压催化氢化制取山嵛酸 总被引:5,自引:1,他引:4
报告了以Ni-Cu为催化剂常压催化氢化芥酸制取山嵛酸的方法,对催化剂的组成和用量、反应温度、反应时间等条件进行了讨论。产率达80%,产品纯度超过97%,催化剂的制备与回收方便,适于工业生产应用 相似文献
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Previous studies found that feeding dairy cows a blend of fish and soybean oils enhanced milk vaccenic acid (VA) and conjugated linoleic acid (CLA) concentrations more than when the oils were fed separately. In these studies, the authors concluded that a component in fish oil was stimulating ruminal VA production from other sources of unsaturated fatty acids; however, that component was not identified. The objective of this study was to determine whether docosahexaenoic acid (DHA), an omega-3 fatty acid (FA) in fish oil, is the active component that promotes trans-C18:1 FA, VA in particular, accumulation using cultures of mixed ruminal microorganisms. Treatments consisted of control, control plus 5 mg of DHA (DH), control plus 30 mg of soybean oil (SBO), and control plus 5 mg of DHA and 30 mg of SBO (DHSBO). Treatments were incubated in triplicate in 125-mL flasks, and 5 mL of culture contents was taken at 0 and 24 h for fatty acid analysis by gas-liquid chromatography. After 24 h of incubation, the level of trans-C18:1 FA (14.1 and 11.7 mg/culture) and VA (13.0 and 10.2 mg/culture) increased more with added DHA than with added SBO, respectively. Combining DHA and SBO yielded higher quantities of trans-C18:1 FA (21.3 mg/culture) and VA (19.8 mg/culture) in the cultures than either fat source alone. These data suggest that DHA is the component in fish oil that promotes VA accumulation when incubated with linoleic acid. 相似文献