应用高效液相色谱法检测功能饮料中6种组分

建立了一种应用高效液相色谱法(HPLC)同时测定功能饮料中维生素B_6、咖啡因、苯甲酸、山梨酸、柠檬黄和胭脂红6种组分的方法。以C_(18)柱(150 mm×4.6 mm, 5μm)为分离柱,以甲醇-20 mmol/L乙酸铵(25.3∶74.7)为流动相,进行等度洗脱,在波长254 nm处检测。该方法中,维生素B_6、苯甲酸和咖啡因在0.10～100 mg/L范围内与其峰面积呈良好的线性关系,检出限均为0.050 mg/L;柠檬黄、胭脂红和山梨酸分别在0.010～10, 0.050～100和0.025～25 mg/L范围内与其峰面积呈良好的线性关系,检出限分别为0.005 0, 0.030和0.012 mg/L。当维生素B_6、咖啡因和苯甲酸的添加量为15.00, 25.00和35.00 mg/L,山梨酸的添加量为3.75, 6.25和8.75 mg/L,胭脂红和柠檬黄的添加量为1.50, 2.50和3.50 mg/L时,加标回收率为87.17%～103.30%,相对标准偏差(RSD)不大于5.31%(N=4)。该方法可用于功能饮料中6种常见组分的同时检测与分析。     

反相高效液相色谱法同时测定黄豆酱中的苯甲酸、山梨酸、安赛蜜

建立一种用反相高效液相色谱法同时测定黄豆酱中苯甲酸,山梨酸和安赛蜜的新方法。样品经酸化后,用无水乙醚萃取,并浓缩吹干,再加入碳酸氢钠溶液溶解,样品调p H后,采用C18柱(250mm×4.6mm,5μm)分离,以甲醇(5%)+0.02mo L/L乙酸铵溶液(95%)为流动相,流速1.0m L/min,检测波长214nm(安赛蜜)及230nm(苯甲酸和山梨酸),出峰时间定性,外标法定量。结果表明:该方法的检出限为1mg/kg,线性范围为1~50μg/m L,相关系数分别为:安赛蜜R=0.99995;苯甲酸R=1.00000;山梨酸R=0.99993。回收率分别为:安赛蜜89.4%~94.1%;苯甲酸97.6%~101%;山梨酸89.6%~93.2%。相关标准偏差(RSD)分别为:安赛蜜0.38%~2.32%;苯甲酸0.26%~1.04%;山梨酸0.44%~1.82%。该方法准确方便,灵敏度高,可实现黄豆酱中苯甲酸、山梨酸、安赛蜜的测定。     

超高效液相色谱测定蜂蜜及其制品中的苯甲酸、山梨酸

研究蜂蜜及其制品中的山梨酸与苯甲酸两种防腐剂的提取净化及其超高效液相色谱检测方法。样品用水溶解,超声波辅助提取样品中的山梨酸与苯甲酸。样液经高速离心,滤膜过滤后,采用超高效液相色谱梯度洗脱与二极管阵列检测器测定样品中的山梨酸与苯甲酸的含量。以BEH Shield RP18(2.1mm × 100mm,1.7μm)为色谱柱,以0.02mol/L 乙酸铵溶液和乙醇为流动相梯度洗脱,两种防腐剂在4min 中内实现较好的分离。方法检出限：苯甲酸为2.5mg/kg,山梨酸为2.0mg/kg。以加标样品做添加回收率测定,苯甲酸与山梨酸的回收率分别为94.1%～102.3% 和96.2%～99.8%,相对标准偏差均小于5%。方法简单、快速准确、灵敏度高是一种较好的定性和定量方法。     

HPLC测定食品中柠檬黄方法的研究

为了更准确地测定食品中的柠檬黄,将样品前处理后,过0.45μm膜,采用戴安高效液相色谱仪测定,色谱柱为Luna5uC18（2）100A,250×4.6mm,柱温30.0℃,以甲醇＋0.02mol/L乙酸铵为流动相,进样量为10μL,检测波长为420nm,并同时进行了回收率的试验。结果表明,该法可消除样品中苯甲酸和山梨酸...     

HPLC法同时测定复合食品防腐剂中苯甲酸、山梨酸和脱氢乙酸

应用高效液相色谱法测定复合食品防腐剂中苯甲酸、山梨酸和脱氢乙酸的含量。样品用水提取后,甲醇和0.02mol/L乙酸铵15∶85(v/v)为流动相洗脱,经Syncronis aQ(4.6mm×150mm,5μm)色谱柱分离,二极管阵列检测器检测,检测波长为225nm。苯甲酸、山梨酸和脱氢乙酸的质量浓度在2 50mg/L的范围内与其峰面积成线性关系,线性方程分别为y=38273x-8760.9、y=48559x+10538、y=52126x+4283.4,检出限均为0.1mg/L。苯甲酸平均回收率为98.8%101.0%,相对标准偏差≤1.8%(n=6);山梨酸平均回收率为97.5%100.1%,相对标准偏差≤2.2%(n=6);脱氢乙酸平均回收率为99.5%101.0%,相对标准偏差≤2.2%(n=6)。该方法精确度和准确性好、灵敏度高,样品预处理简单,避免了滴定分析方法中复配防腐剂之间相互干扰的问题,是复合食品防腐剂中各种成分含量测定的理想检测方法。     

高效液相色谱法测定牛奶中3种防腐剂

建立高效液相色谱法测定牛奶中的苯甲酸、山梨酸和脱氢乙酸残留量的方法.样品经体积分数为0.2％乙酸沉淀蛋白,提取过滤后,以乙腈-0.02 mol/L乙酸铵溶液为流动相,经C18反相色谱柱分离,二极管阵列检测器检测.结果表明,苯甲酸和山梨酸的检出限为0.005 mg/g,定量限为0.01 mg/g,脱氢乙酸的检出限为0.0...     

HPLC法测定熟肉制品中苯甲酸、山梨酸和脱氢乙酸的含量

建立HPLC法测定熟肉制品中苯甲酸、山梨酸和脱氢乙酸含量的方法。色谱柱为Thermo Acclaim TM C18(250 mm×4.6 mm,5μm);流动相:甲醇-0.02 mol/L乙酸铵溶液(7:93,v/v);流速:1.0m L/min;检测波长:230 nm;柱温:35℃。结果表明,该方法具有良好的精密度与稳定性,苯甲酸、山梨酸和脱氢乙酸分别在1.17~27.96、1.11~26.63、1.08~25.89μg/m L范围内线性良好,其平均回收率分别为90.4%、94.4%、86.8%。实验结果表明该方法简便、结果准确、重现性好,适用于熟肉制品中苯甲酸、山梨酸及脱氢乙酸的含量测定,为熟肉制品中添加剂的检测奠定了基础。     

超高效液相色谱法同时快速测定陈年道菜中安赛蜜、苯甲酸、山梨酸、糖精钠、脱氢乙酸

建立了一种同时快速测定陈年道菜中安赛蜜、苯甲酸、山梨酸、糖精钠、脱氢乙酸的超高效液相色谱法。样品前处理后,经Agilent Ecilpse Plus C18(50mm×2.1mm,1.8μm)色谱柱分离,以甲醇-20mmol/L乙酸铵的乙酸溶液(pH 5.28)为流动相进行梯度洗脱,采用二极管阵列检测器,检测波长为230nm,流速为0.30mL/min,柱温为40℃,以保留时间定性,外标法峰面积定量。结果表明,安赛蜜、苯甲酸、山梨酸、糖精钠、脱氢乙酸在5min内可以完全分开,样品在0.02～0.10g/kg添加三水平范围内的回收率在66.43%～102.87%之间,相对标准偏差小于3.2%。该方法快速准确,分离效果好,适用于陈年道菜中安赛蜜、苯甲酸、山梨酸、糖精钠、脱氢乙酸的快速检测。     

毛细管气相色谱法同时测定果汁中山梨酸、苯甲酸、脱氢乙酸

目的建立同时快速测定果汁中山梨酸、苯甲酸、脱氢乙酸的毛细管气相色谱法。方法果汁样品经液-液萃取后,样品中山梨酸、苯甲酸、脱氢乙酸经过毛细管柱分离,气相色谱FID检测器进行检测。结果本方法在10 min内可完成定性和定量检测,方法的线性范围为100～500 mg/L,线性相关系数都大于0.999,3种添加剂的测定结果的相对标准偏差(n=7)都小于3%,山梨酸、苯甲酸、脱氢乙酸在100、300、600 mg/L添加水平的回收率为89.9%～108.9%。结论该方法快速、灵敏、性价比高,适合测定果汁中山梨酸、苯甲酸、脱氢乙酸的测定。     

HPLC法同时快速测定酱油中的苯甲酸、山梨酸、糖精钠、安赛蜜

建立了一种同时快速测定酱油中苯甲酸、山梨酸、糖精钠、安赛蜜的高效液相色谱法。样品经水提取,取离心后的上清液,过0.22μm滤膜,高效色谱仪(C18柱)分析。色谱条件:色谱柱为C_(18)柱,柱温35℃,流动相为甲醇-0.02mol/L乙酸铵(体积比为5∶95),流速1.0mL/min,二极管阵列检测器检测,以保留时间定性,外标法峰面积定量。结果表明,样品在10～100mg/kg添加水平范围内,苯甲酸、山梨酸、糖精钠、安赛蜜的回收率在90%～104%,相对标准偏差小于3%。该方法简便、准确,适用于酱油中苯甲酸、山梨酸、糖精钠、安赛蜜的快速检测。     

Anti-obesity effects of conjugated linoleic acid, docosahexaenoic acid, and eicosapentaenoic acid

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.     

RP-HPLC法同时测定糕点中安赛蜜、苯甲酸、山梨酸、糖精钠和脱氢乙酸

建立反相高效液相色谱法(RP-HPLC同时测定糕点中安赛蜜、苯甲酸、山梨酸、糖精钠和脱氢乙酸。该方法糕点样品经处理后,采用SunFire C185μ4.6 mmmm反相色谱柱,流动相为甲醇:磷酸盐缓冲液(pH6.7=793等度洗脱,流速为1.0 mL/min检测波长230 nm柱温为30℃进样量为20μ。线性范围0.2 mg/L120 mg/L检出限0.4 mg/kg1.0 mg/kg加标回收率为87.7%105.3%相对标准偏差小于5%。结果表明,该方法操作简便、结果可靠,可用于同时检测糕点中安赛蜜、苯甲酸、山梨酸、糖精钠和脱氢乙酸。     

无铬酸、氢氟酸、硝酸的新型不锈钢抛光工艺

不锈钢抛光工艺，传统配方多有铬酸、氢氟酸、硝酸等毒害较大物质，对环境污染较大，同时采用高温酸洗，去除氧化皮等，使成本增加。本文介绍不锈钢的粗抛、细抛、精抛是将酸洗、化抛、电抛融为一体的不锈钢抛光组合工艺，不仅显著地降低了环境污染，还确保了不锈钢光亮如镜的靓兰色泽，这在生产实践中得到验证。     

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

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。     

花生四烯酸、二十二碳六烯酸和二十碳五烯酸 在炎症中的作用概述

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。     

气相色谱法测定鱼油中的二十碳五烯酸、 二十二碳六烯酸和二十二碳五烯酸

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。     

Simultaneous determination of dehydroacetic acid,benzoic acid,sorbic acid,methylparaben and ethylparaben in foods by high-performance liquid chromatography

In this study, an analytical method was established and validated to determine the preservatives such as dehydroacetic acid, benzoic acid, sorbic acid, methylparaben and ethylparaben. The level of preservatives was measured by solvent extraction method adding purification process with carrez reagent and by high-performance liquid chromatography (HPLC). The developed analytical method was successfully applied to determine the concentration of preservatives in various food samples including jam, cheese and soy sauce, displaying high accuracy (recoveries between 87.8% and 110%) and precision (%RSD less than 5.92% and 7.72% for intra-day and inter-day, respectively). To verify the applicability of the improved test method, selected 13 food items and collected 521 samples were monitored. As a result, all the cases met the Korea standard guidelines. Consequently, this study is expected to contribute to the safety management of preservatives for domestic distribution and imported food.

     

Photostabilization of ascorbic acid with citric acid, tartaric acid and boric acid in cream formulations

This study involves the evaluation of the effect of certain stabilizers, that is, citric acid (CT), tartaric acid (TA) and boric acid (BA) on the degradation of ascorbic acid (AH(2) ) in oil-in-water cream formulations exposed to the UV light and stored in the dark. The apparent first-order rate constants (0.34-0.95 × 10(-3) min(-1) in light, 0.38-1.24 × 10(-2) day(-1) in dark) for the degradation reactions in the presence of the stabilizers have been determined. These rate constants have been used to derive the second-order rate constants (0.26-1.45 × 10(-2) M(-1) min(-1) in light, 3.75-8.50 × 10(-3) M(-1) day(-1) in dark) for the interaction of AH(2) and the individual stabilizers. These stabilizers are effective in causing the inhibition of the rate of degradation of AH(2) both in the light and in the dark. The inhibitory effect of the stabilizers is in the order of CT > TA > BA. The rate of degradation of AH(2) in the presence of these stabilizers in the light is about 120 times higher than that in the dark. This could be explained on the basis of the deactivation of AH(2) -excited triplet state by CT and TA and by the inhibition of AH(2) degradation through complex formation with BA. AH(2) leads to the formation of dehydroascorbic acid (A) by chemical and photooxidation in cream formulations.     

Determination of mycophenolic acid, penicillic acid, patulin, sterigmatocystin, and aflatoxins in cheese.

A method has been developed for detection of aflatoxins, mycophenolic acid, patulin, penicillic acid, and sterigmatocystin in cheese. It is based on selective extraction with a mixture of equal volumes of 5% sodium chloride, methanol, and aceton, precipitation of caseins at -25 C, defatting with hexane, and removal of extraneous matter by transfer of mycotoxins to chloroform and ethyl acetate. The extract is purified further by column chromatography. Mycotoxins are quantitated on thin layer chromatograms by fluorescence comparisons. Mycophenolic acid, patulin, and penicillic acid are visualized with diethylamine. The limits of detection in cheese are about 20 micrograms/kg for mycophenolic acid, patulin, and sterigmatocystin, 30 microgram/kg for pencillic acid, and 1 microgram/kg for aflatoxins B1 and M1.     

富硒豆豉中安赛蜜、苯甲酸、山梨酸、糖精钠、 脱氢乙酸的测定

目的建立高效液相色谱法同时测定富硒豆豉中安赛蜜、苯甲酸、山梨酸、糖精钠和脱氢乙酸的分析方法。方法样品经过沉淀剂沉淀蛋白后过滤,使用C_(18)反向色谱柱(pH1.5～9.0)分离,用甲醇-乙酸铵溶液作为流动相进行洗脱,经高效液相色谱紫外检测器和二极管阵列检测器检测,检测波长为230 nm。结果 5种添加剂具有良好的线性关系,相关系数均大于0.9990,检出限为1.0～2.0mg/kg。应用该方法检测富硒豆豉的加标回收率为90.2%～101.1%,相对标准偏差小于2.0%。结论本研究建立的方法有效可行,结果可靠,适用于富硒豆豉中5种添加剂的检测。