共查询到20条相似文献,搜索用时 85 毫秒
1.
2.
3.
4.
支链淀粉—三(苯基氨基甲酸酯)手性固定相的制备及对外消旋环酮和环醇的直? 总被引:1,自引:0,他引:1
在参照文献基础上上,合成并制备了支链淀粉-三(苯基氨基甲酸酯)手性固定相,以此手性固定相为基础,利用高效液相色谱首次直接拆分了3种外消旋环酮和一种外消旋环醇,并考察了流动相中异丙醇含量对拆分的影响。 相似文献
5.
干燥方式对含直链淀粉半互穿网络水凝胶溶胀和降解的影响 总被引:1,自引:1,他引:0
以4,4′-二甲基丙烯酰胺基偶氮苯(BMAAB)为交联剂,制备了丙烯酸-丙烯酰胺-甲基丙烯酸酯共聚物和直链淀粉半互穿网络水凝胶.以冷冻干燥和空气干燥两种方式,研究了干凝胶在pH2.2和pH7.4时的溶胀和降解性能.结果表明采用两种干燥方式的凝胶在不同pH的介质中都遵循二级溶胀动力学.凝胶内部水的扩散均为非Fickian机理,即扩散和链松弛协同作用的机理.但经历冷冻干燥的凝胶其扩散机制占优势.在pH=7.4的介质中,冷冻干燥凝胶的平衡溶胀比(SR)显著增大,而在pH=2.2时则无明显变化.扫描电镜(SEM)和降解实验发现,在结肠内容物的作用下,冷冻干燥凝胶在5天内降解率可达35.3%,而空气干燥凝胶的降解率为28.1%,表明冷冻干燥的方式可在一定程度上促进凝胶在结肠环境下的降解. 相似文献
6.
利用直链淀粉与甘/丙氨酸乙酯共取代聚膦腈交联, 制得了一种具有网络结构的新型杂化材料. 实验结果表明, 淀粉衍生物上的羟基转变为醇钠后, 可与聚膦腈分子链上的P-Cl键发生亲核取代反应; 所得聚合物膜无明显相分离, 力学性能优于具有相似组成的直链淀粉/聚膦腈共混膜, 表面亲水性和吸水率与对应的共混膜接近, 且均高于纯聚膦腈膜. 因此, 该聚合物可作为杂化生物材料用于药物控制释放和组织工程方面的研究. 相似文献
7.
在自制的直链淀粉-三(3,5-二甲基苯基氨基甲酸酯)(ADMPC)手性固定相上,对2种氮杂环丙烷对映体进行了手性拆分研究.系统选用了不同种类及不同含量的醇改性剂,详细考察了样品的保留时间和立体选择性. 相似文献
8.
选用不同的醇改性剂,在自制的直链淀粉-三(3,5-二甲基苯基氨基甲酸酯)(ADMPC)手性固定相上,对2种吲哚环衍生物对映体进行了手性拆分研究,并考察了样品的保留时间和立体选择性. 相似文献
9.
10.
11.
12.
缺铁性贫血是我国人群普遍存在的营养性疾病之一.综述了我国富铁食品的开发状况,并就富铁食品的应用前景进行展望. 相似文献
13.
中国富硒食品的生产现状及趋势 总被引:2,自引:0,他引:2
对硒的生物学作用和目前已经开发的富硒食品(富硒西瓜、富硒灵芝、富硒茶叶、富硒牛奶、富硒猪肉和富硒鸡蛋等)进行了概述。当前富硒食品的技术含量大多偏低,技术水平有待提高;价廉物美的富硒食品受市场欢迎,科学论证富硒食品的转化机制是今后科研的一个方向。 相似文献
14.
介绍了食品中无机盐前处理和检测技术研究进展,主要阐述了包括火焰原子吸收光谱法、石墨炉原子吸收光谱法、电感耦合等离子体原子发射光谱法、原子荧光光谱法、X射线荧光光谱法及联用等技术在近年来的应用,并对以后的发展方向进行了展望。 相似文献
15.
16.
17.
从食品检测方法的分类、检测流程、检测标准选择,样品处理,宏观营养成分检测,微观营养物质分析等方面详细举例,分析了思维导图在食品理化检测技术课程中的应用。通过思维导图的13个应用实例和学习评价实践表明:在食品理化检测教学中应用思维导图,可以帮助学习者快速、准确掌握食品理化检测相关学习任务,掌握各类物质的检测技能,快速完成检测任务。 相似文献
18.
Veronika Valkov Hana úranov Nenad L. Vukovic Milena Vukic Maciej Kluz Miroslava Ka
niov 《Molecules (Basel, Switzerland)》2022,27(10)
The possibilities of the practical utilization of essential oils (EOs) from various plant species in the food industry have attracted the attention of the scientific community. Following our previous studies, the antifungal activities of three further commercial EOs, Melaleuca armillaris subsp. armillaris (rosalina; REO), Melaleuca quinquenervia (niaouli; NEO), and Abies alba (fir; FEO), were evaluated in the present research in respect to their chemical profiles, over four different concentrations, 62.5 μL/L, 125 μL/L, 250 μL/L, and 500 μL/L. The findings revealed that the major compounds of REO, NEO, and FEO were linalool (47.5%), 1,8-cineole (40.8%), and α-pinene (25.2%), respectively. In vitro antifungal determinations showed that the inhibition zones of a Penicillium spp. mycelial growth ranged from no inhibitory effectiveness (00.00 ± 00.00 mm) to 16.00 ± 1.00 mm, indicating a very strong antifungal activity which was detected against P. citrinum after the highest REO concentration exposure. Furthermore, the in situ antifungal efficacy of all EOs investigated was shown to be dose-dependent. In this sense, we have found that the highest concentration (500 µL/L) of REO, NEO, and FEO significantly reduced (p < 0.05) the growth of all Penicillium strains inoculated on the bread, carrot, and potato models. These results indicate that the investigated EOs may be promising innovative agents in order to extend the shelf life of different types of food products, such as bread, carrot and potato. 相似文献
19.
Thirupathi Dongala Naresh Kumar Katari Ashok Kumar Palakurthi Sreekantha B. Jonnalagadda 《Biomedical chromatography : BMC》2019,33(11)
A novel generic reverse phase high performance liquid chromatography (RP‐HPLC) method is developed and validated for simultaneous determination of seven pharmaceutically active ingredients, namely, acetaminophen, dextromethorphan, doxylamine, phenylephrine, guaifenesin, caffeine and aspirin. All seven ingredients were quantified in soft gel, syrup and tablet formulations of the over‐the‐counter US‐marketed products, as per the guidelines of the International Conference on Harmonization. The separation was achieved in a 16 min run time on an Agilent Zorbax Phenyl column using a gradient method with two mobile phases. Mobile phase A was 0.15% trifluoro acetic acid in purified water and while mobile phase B was a mixture of acetonitrile and methanol (750:250 v/v) with 0.02% trifluoro acetic acid. The flow rate was 1.0 mL min?1 and injection volume was 10 μL. Detection was performed at 280 nm using a photodiode array detector. As part of the method validation, specificity, linearity, precision and recovery parameters were verified. The concentration and area relationships were linear (R2 > 0.999), over the concentration ranges 20–120 μg mL?1 for acetaminophen, 75–450 μg mL?1 for dextromethorphan, 31.25–187.5 μg mL?1 for doxylamine, 25–150 μg mL?1 for phenylephrine, 25–150 μg mL?1 for aspirin, 6.5–39 μg mL?1 for caffeine and 12–72 μg mL?1 for guaifenesin. The relative standard deviations for precision and intermediate precision were <1.5%. The proposed RP‐HPLC generic method is applicable for routine analysis of cold and cough over‐the‐counter products. 相似文献
20.
Hayat Mohammad Mukhtar Varinder Soni Atinderpal Singh Hardeep Kaur 《Natural product research》2019,33(19):2868-2872
A simple, rapid, accurate and precise RP-HPLC method was developed for the determination of stigmasterol in botanical extract of Ficus deltoidea. Separation was achieved with acetonitrile and acetic acid in water (75:25% v/v) in isocratic mode at 210?nm. Single sharp peak of standard stigmasterol was detected at retention time 3.17?min which overlay with the peak of plant extract at 3.14?min. The calibration curve was found to be linear in a concentration range of 2–10?μg/ml with correlation coefficient of 0.998. The LOD and LOQ were found to be 1.50?μg/ml and 4.55?μg/ml respectively. Accuracy and precision was determined with overall recovery of 99.6–100.1% for stigmasterol and RSD values in both intra-day and inter-day repeatability assay lesser than 0.340%, respectively. The robustness study also indicated that there is no influence of minor changes in detecting wavelength and flow rate of mobile phase on the response. 相似文献