大豆异黄酮提取-测定优化体系的建立

利用超声波法提取大豆异黄酮,结合三波长紫外分光光度法测定大豆异黄酮含量,对大豆异黄酮提取方法进行优化.结果获得的最优提取条件为:料液比1:20、乙醇浓度50%、提取时间30 min,提取2次;并用三波长法测定24个大豆品种异黄酮含量,发现品种间异黄酮含量有显著差异,其中吉林32和吉林35含量最高,分别达到了0.292%...     

坛紫菜甲醇提取物屏蔽紫外能力的研究

分别用浓度为80%,90%和100%的甲醇提取坛紫菜的天然防晒物质,分析其紫外吸收能力和抗氧化能力。结果表明,采用80%的甲醇对坛紫菜进行提取的效果最好。坛紫菜的MAAs粗提物在紫外波段(ultraviolet radiation,UVR,280～400 nm)具有明显的吸收峰,说明该提取物具有良好的紫外吸收能力。将MAAs粗提物与市购防晒乳霜(自然堂,SPF18)分别按质量比为1∶30,1∶20,1∶10和1∶5的比例混合后,MAAs粗提物可以显著改良市购防晒乳霜的抗紫外能力,其防晒系数(SPF,sun protection factor)分别增大到22,43,87和114。MAAs粗提物对DPPH和羟自由基的清除率分别为12.82%和0.58%。因此,MAAs粗提物可作为功效成分添加剂应用于防晒化妆品中。     

淡豆豉中多指标成分的含量测定方法研究

建立淡豆豉中多指标成分含量测定方法,采用HPLC法同时测定淡豆豉中大豆苷元和染料木素含量,UV法测定总异黄酮含量。色谱条件:Agilent HC-C18色谱柱(250×4.6 mm,5.0μm);甲醇-0.1%冰醋酸(50∶50)为流动相;流速1 mL.min-1;检测波长261 nm;柱温30℃;进样量10μL。紫外分光光度计采用261 nm波长测定淡豆豉提取液的吸光度值。结果表明:大豆苷元和染料木素色谱峰的分离度良好,淡豆豉中大豆苷元、染料木素的保留时间分别为9.79和14.87 min,峰面积积分值与进样量呈良好的线性(r>0.9999),平均回收率分别为98.90%和100.53%。总异黄酮含量测定线性范围为1.44～7.20μg.mL-1,平均回收率为102.26%。该法简便易行,能够用于评价淡豆豉质量。     

紫外分光光度法测定转基因烟草叶片中自藜芦醇的含量

利用紫外分光光度法对转基因烟草叶片中自藜芦醇的含量进行了测定。结果显示,转入花生白藜芦醇合成酶基因的烟草叶片中自藜芦醇浓度约为6．83μg/ml,比野生型材料中约5．11μg/ml的白藜芦醇含量略高。经紫外胁迫诱导后,其叶片中自藜芦醇含量分别提高到10．98μg/ml和9．25μg/ml。白藜芦醇合成酶转人烟草后不仅使目标植物中白藜芦醇含量有所增加,而且使植物自身对紫外胁迫的耐受能力也得到了较大的提高。     

基于bipppx(吡唑类)金属配合物的合成及抑菌性能研究

[目的]以双[3-（4-吡啶）吡唑基]-对二甲苯（bipppx）为配体与锌（Ⅱ）、镉（Ⅱ）、铜（Ⅱ）、钴（Ⅱ）的4种金属盐进行反应合成4种配合物,并对其进行抑菌活性研究。[方法]将配体bipppx溶于无水乙醇中,分别加入硝酸锌、乙酸镉、乙酸铜、乙酸钴,加热回流,过滤干燥得目标化合物;运用紫外光谱分析其配位情况;采用纸片法对其进行抑菌活性研究。[结果]抑菌活性试验结果表明,配体及配合物对大肠杆菌、产气杆菌的抑菌性较为明显,对金黄色葡萄球菌无明显抑菌作用,并且以bipppx-Co（Ⅱ）配合物的抑菌活性最佳。[结论]bipp-px金属配合物的制备为配位化学增添新的内容,良好的抑菌活性为其在农业、医药上的应用提供了依据。     

Mn~（2＋）/UV催化O_3处理造纸废水的研究

以镁化合物、膨胀珍珠岩为原料,在室温条件下与水混合,干燥后即制得催化剂载体,通过表面负载MnSO4制备成一种新型Mn2＋催化剂。该催化剂平均密度为1.03 g/cm3,略大于水,可在反应器内很好流化。电镜扫描和能谱分析表明,Mn2＋在催化剂载体表面负载及催化性能稳定。对Mn2＋/UV催化O3处理造纸废水进行了试验研究,结果表明,对于COD为523 mg/L的造纸废水,在催化剂投加量为20 g、O3曝气量为60 ml/min、曝气时间为40 min、pH为7、紫外灯照射功率为30 W的最佳条件下,COD去除率可达到73%以上。     

金银花中绿原酸的提取和含量测定

[目的]研究金银花中绿原酸的不同提取方法并测定了不同花期金银花中绿原酸的含量。[方法]以金银花为材料,采用乙醇回流法和超声提取法提取金银花中的绿原酸,并以紫外分光光度法测定提取物中绿原酸的含量,探讨了不同开花时期金银花中绿原酸含量的差异。[结果]以乙醇回流法提取的金银花原液中绿原酸浓度为1.905 mg/ml,含量为3.81%,而以超声提取法提取的金银花原液中绿原酸浓度为1.306 mg/ml,含量为2.61%,故乙醇回流法比超声提取法提取率更高一些;以乙醇回流法提取的全开金银花原液中绿原酸浓度为0.167 7 mg/ml,含量为0.34%,而以乙醇回流法提取的花苞原液中绿原酸浓度为0.260 1 mg/ml,含量为0.52%,故花苞中的绿原酸含量要高一些。[结论]该方法操作简便迅捷,可用于金银花中绿原酸的提取和含量测定。     

Photodegradation of emamectin benzoate and its influence on efficacy against the rice stem borer, Chilo suppressalis

Emamectin benzoate, a novel insecticide with characteristics of translaminar movement into plant leaf tissue, was derived from the avermectin family with improved thermal stability, greater water solubility and a broader spectrum of insecticidal activity than avermectin. To quantify UV photodegradation of emamectin benzoate, HPLC analysis was conducted to quantify residues of MAB1a, the major component in emamectin benzoate, after exposure to UV light for different lengths of time. Results showed both MAB1a concentration and length of UV light exposure (0-120 h) had significant impacts on photodegradation rate. The degradation rate increased as exposure duration increased, but decreased as initial MAB1a concentration increased. Four UV protectants, kojic acid, sodium ligninsulfonate, soybean lecithin and milk, were evaluated for their effect on UV degradation. Results showed that kojic acid could effectively reduce the photodegradation of MAB1a. In addition, the photodegradation of emamectin benzoate was also examined for its influence on the efficacy against the rice stem borer, Chilo suppressalis. The results of the bioassays were consistent with those of HPLC analysis. The initial concentration of emamectin benzoate and exposure duration to UV light both had significant influences on the efficacy against C. suppressalis. As the UV exposure time increased, the efficacy of emamectin benzoate against C. suppressalis decreased. The results indicated that UV photodegradation has a significant effect on the efficacy of emamectin benzoate against C. suppressalis and the effect is concentration-dependant. In addition to understanding the critical factor of UV exposure length, this study also showed that maintaining emamectin benzoate concentration above a certain level in the formulation and the application solution, and applying UV protectants may reduce photodegradation and increase efficacy against target pests.     

紫外吸收光谱法对聚丙烯中抗氧剂3125的定量分析

采用紫外吸收光谱法定量分析聚丙烯(Polypropylene,PP)中抗氧剂3125的含量,经分析得到PP/抗氧剂3125体系和PP/抗氧剂168(定量)/抗氧剂3125体系中抗氧剂3125的特征波长,并得出了抗氧剂3125含量与特征波长吸光度关系的标准曲线,其相关系数均大于0.98.经试验验证,样品中抗氧剂3125的计算值与测量值相对误差均不超过8%,适用于实际检测的需要.