高效液相色谱法测定海洋生物中牛磺酸的含量

[目的]建立牛磺酸的高效液相色谱分析方法,并通过该方法测定不同海洋生物中牛磺酸的含量。[方法]应用邻苯二甲醛(OPA)柱前衍生法,研究流动相比例、流速、衍生剂比例、衍生时间等因素对牛磺酸检测的影响。[结果]当牛磺酸∶OPA=1∶2,衍生时间2 min,流动相乙腈∶水=15∶85,流速为0.5 mL/min,检测波长为360 nm时,牛磺酸浓度为10~400μg/mL时具有良好的线性关系(R~20.99),平行样品的相对标准偏差为2.9%~7.4%。利用该方法检测不同海产品中牛磺酸的含量,所选择的海洋贝类、甲壳类、鱼类中均含有牛磺酸,其中海瓜子中含量最高,达11.2 mg/g。不同组织比较,鱼肉中牛磺酸含量较高,而鳃中较低。[结论]该研究结果丰富了海洋生物中牛磺酸含量的数据,为进一步研究牛磺酸在不同组织中的合成机制提供了参考。     

HPLC法测定玉米酒糟中绿原酸的含量

采用浸提法提取玉米酒糟中绿原酸并用HPLC法测定其中的含量,采用安捷伦色C18（4.6mm×150mm,5μm）色谱柱,乙腈-0.5％磷酸溶液为流动相,流速为1.0mL·min-1,检测波长为327nm.结果表明绿原酸在0.232～2.784μg呈现良好的线性关系,玉米酒糟中绿原酸含量0.028％,平均回收率为95.80％,RSD=2.72％.试验证明了玉米酒糟中含有绿原酸,且其含量较高,为玉米酒糟的进一步开发提供科学依据.     

Evaluation of Commercial Fe(III)‐Chelates Using Different Methods

Abstract

A collaborative assay among three laboratories was made in order to compare both the ion (CEN. EN 13368‐2:2001 E. Determination of chelating agents in fertilizers by ion chromatography. Part 2: EDDHA and EDDHMA, 2001a) and the ion‐pair (Lucena, J.J.; Barak, P.; Hernandez‐Apaolaza, L. Isocratic ion‐pair high‐performance liquid chromatographic method for the determination of various iron(III) chelates. J. Chromatogr. A 1996, 727, 253–264) high performance liquid chromatography (HPLC) methods as well as the soluble and complexed Fe (CEN. EN 13366:2001 E. Treatment with a cation exchange resin for the determination of the chelated micronutrient content and of the chelated fraction of micronutrients, 2001b) methods. Fifteen and ten samples of commercial fertilizers of Fe‐EDDHA, Fe‐EDDHMA, respectively were analysed by three laboratories using these methods. No significant differences were observed between the results obtained for the Fe‐EDDHA content using the Lucena et al. or CEN method. The first method makes it possible to distinguish between the meso and DL‐racemic diasteroisomers of Fe‐o, o‐EDDHA. For the Fe‐EDDHMA formulations, the CEN method gives higher values than the ion‐pair method, since in the first one Fe‐EDDH4,6MA coelutes with FeEDDHMA. Also the CEN method does not makes it possible to distinguish between Fe‐EDDHMA and Fe‐EDDH5MA products. The variability among laboratories was larger for the CEN method than for the Lucena et al. method.     

Toxicity of Bacillus thuringiensis Crystal Toxins to Field Populations of Rice Leaf Folder, Cnaphalocrocis medinalis （Guenee） and Establishment of Baseline Susceptibility to Cry1Ab

Eight insecticidal crystal proteins of Bacillus thuringiensis, CrylAa, CrylAb, CrylAc, CrylB, Cry2Aa, CrylC, CrylDa and Cry 1Ea were assessed for toxicity against 1 st instar larvae of rice leaf folder, Cnaphalocrocis medinalis （Guenee） at 48 HAT and 72 HAT. Bioassay results depicted CrylAa was the most toxic （LCso 2.35 ppm） followed by CrylBa （LCso 8,50 ppm） and CrylAb （LCso 8.73 ppm） at 48 HAT, whereas, at 72 HAT CrylAb proved to be highly toxic （LC50 0.50 ppm） followed by CrylAa （LCso 4.07 ppm）, CrylAc （LCso 4,84 ppm） and CrylBa （LCso 6.42 ppm）. Toxins Cry2Aa, CrylCa, CrylDa and CrylEa did not resulted in any mortality at 48 HAT and 72 HAT, respectively. Baseline estimates for CrylAb against 1st instar larvae of C. medinalis sampled from seven geographical locations revealed variation in LC50＇s from 0.37 ppm to LC50 16.25 ppm at 48 HAT and LC50 0.50 ppm to LC50 6.49 ppm 72 HAT, respectively with relative resistance ratios of 44-fold and 13-fold at 48 HAT and 72 HAT over the susceptible population.     

黄连及黄连须、黄连茎叶体外抗氧化活性的谱效关系研究

测定黄连与黄连须、黄连茎叶主要生物碱含量并建立高效液相(HPLC)指纹图谱,分析其抗氧化活性的谱效关系。采用HPLC分析比较黄连及黄连须、黄连茎叶中小檗碱、表小檗碱、药根碱、黄连碱、巴马汀含量差异并建立指纹图谱,通过羟自由基(·OH)、1,1-二苯基-2-三硝基苯肼(DPPH)自由基、2,2-联氮基双(3-乙基苯并噻唑啉-6-磺酸)(ABTS)自由基体外清除试验与总还原力试验评价其体外抗氧化活性差异,应用Pearson相关系数法分析HPLC指纹图谱与抗氧化活性的谱效关系。结果发现小檗碱、巴马汀含量为黄连>黄连茎叶>黄连须;药根碱、黄连碱和表小檗碱含量为黄连>黄连须>黄连茎叶;总还原力为黄连>黄连茎叶>黄连须,·OH、DPPH、ABTS·+自由基清除力为黄连茎叶>黄连>黄连须;总还原力与各峰均有较强相关性,·OH、DPPH、ABTS·+自由基清除力与4号峰相关性较强。说明黄连茎叶体外抗氧化活性较强,黄连须与黄连茎叶均有一定药用开发价值。     

Variation among stallions in sperm quality after single layer centrifugation

Although single layer centrifugation (SLC) selects robust spermatozoa from stallion semen, the effect of individual variation has not been studied in detail. The objective of this study was to determine the variation among stallions in the effects of SLC on sperm quality during cooled storage for up to 48 hr. Semen samples from seven stallions (18 ejaculates) were split, with one portion being used for SLC and the other serving as a control (CON). Sperm quality (kinematics, reactive oxygen species (ROS) production, membrane integrity (MI) and chromatin integrity) were analysed at 0, 24 and 48 hr using computer-assisted sperm analysis and flow cytometry. Sperm quality was better in SLC than in CON at all timepoints, especially chromatin integrity and MI (p < .0001 for both), and some categories of ROS production (e.g. proportion of live hydrogen peroxide negative spermatozoa, p < .0001), but the degree of improvement varied among stallions and type of ROS (p < .05–p < .0001). Total and progressive motility were also better in SLC samples than in CON at 24 and 48 hr (p < .0001), although the effect on sperm kinematics varied. The interaction of treatment, time and stallion was not significant. In conclusion, sperm quality was better in SLC samples than in CON, although there was considerable individual variation among stallions. The improvement in sperm quality, particularly in chromatin integrity, was clearly beneficial, and therefore the use of this technique would be warranted for all stallion semen samples.     

HPLC法测定天然植物粗提物中芍药苷含量

建立高效液相色谱法检测天然植物粗提物饲料原料中芍药苷的测定方法。用十八烷基硅烷键合硅胶色谱柱,以乙腈-0.1%磷酸溶液(14:86)为流动相,检测波长230nm,流速：1.0 mL/min;柱温：30 ℃;进样量：10μL。结果显示,芍药苷的线性方程为Y=10.6017X－14.8514,(r=0.99966,n=6),本方法的回收率为100.4~102.1%,RSD均小于2.0%。结果表明,本方法准确,可靠,适用于天然植物粗提物饲料原料中芍药苷的测定。     

超高效液相色谱法测定饲料中斑蝥黄和β-阿朴-8’-胡萝卜素酸乙酯含量方法的研究

为有效快速测定饲料中斑蝥黄和β-阿朴-8’-胡萝卜素酸乙酯含量,饲料经甲醇、正己烷和乙酸乙酯混合液萃取后,在氮气保护下浓缩,用甲基叔丁基醚-乙腈溶液复溶,注入超高效液相色谱仪中进行测定。结果表明:斑蝥黄浓度为1.25~10.0μg/mL,β-阿朴-8’-胡萝卜素酸乙酯为2.50~20.0μg/mL线性关系良好;斑蝥黄和β-阿朴-8’-胡萝卜素酸乙酯的检测限为0.06 mg/kg,定量限为0.20 mg/kg。斑蝥黄5个添加水平的平均回收率为72.8%~82.8%,相对标准偏差(RSD)为0.41%~1.06%;β-阿朴-8’-胡萝卜素酸乙酯5个添加水平的平均回收率为72.0%~82.8%,RSD为0.46%~1.41%。说明该方法简便、快速、灵敏度高、准确度好,适用于测定饲料中斑蝥黄和β-阿朴-8’-胡萝卜素酸乙酯含量。     

利用棉绳采集口腔液监测猪伪狂犬病方法的应用分析

为分析使用棉绳采集口腔液监测猪场伪狂犬病（PR）方法的科学性,本研究拟通过实验室水平、动物试验及临床应用3个方面对使用棉绳采集口腔液监测猪场PR这一方法开展应用分析。首先对采样条件进行优化,并通过模拟试验测定棉绳对伪狂犬病病毒（PRV）的释放能力,通过动物试验测定病毒感染后检出时间,最后对临床样品进行检测分析。结果表明：使用直径为1.0 cm的棉绳,在早上喂料前采集口腔液样品,采样时间为20~30 min,可采集到更能满足试验要求的口腔液。病毒释放能力测定显示,棉绳对PRV的释放能力为50%左右,使用棉绳采集口腔液可检测到1个TCID₅₀/0.1 mL的病毒含量。动物试验检测发现,猪群在感染后28 d中除第5天外,口腔液中病原含量均高于鼻拭子中病原含量,口腔液检测效果优于鼻拭子,且口腔液中病毒的检出时间（感染后第1天）早于血液中抗体转阳时间（感染后第7天）。临床样品检测分析结果表明,PRV疫苗免疫后也可通过口腔液检测到疫苗毒,并且存在无法通过口腔液检测感染PRV野毒后稳定猪中带毒的情况,因此口腔液检测方法应结合gE抗体检测,才可综合判断猪群是否为感染群体。综上,本研究优化了口腔液采集方法,并测定了棉绳对口腔液的释放能力和感染后检出时间,表明口腔液可作为较好的监测猪群PR的手段;口腔液监测方法需结合gE抗体检测来综合判断猪群是否为感染群体。