高效液相色谱法测定大豆中卵磷脂的含量

应用高效液相色谱法(HPLC),选用Kromasil SIL柱,以甲醇/异丙醇/正己烷(60/35/5,V/V)为流动相,采用紫外检测器(205nm)对卵磷脂进行了测定。结果表明,大豆卵磷脂的保留时间为26.035min,定量线性范围2.06~30.9μg(r=0.9999),精密度和稳定性实验相对标准偏差均小于5%,加样回收率达97.41%,表明建立的大豆卵磷脂检测方法灵敏度高、稳定性和重现性好。     

HPLC-ELSD法测定细风轮菜中醉鱼草苷Ⅳ的含量

采用ZORBAX SB-C 18柱(4.6 mm×150 mm,5.0 μm);柱温30℃;流动相:乙腈-水(梯度洗脱:0-30 min:10%～50%乙腈);流速1.0 mL/min;Alhech 2000 ES ELSD检测器;漂移管温度110℃;气体为空气;流速3.0 L/min;进样量5.0μL.建立高效液相色...     

辣椒素类物质在烤制加工和储藏中的稳定性

为了解辣椒素类物质在烤制加工和储藏过程中的稳定性,该文研究了不同加热温度和时间处理以及不同储藏条件下（常温和冷藏,真空和非真空）,野山椒中辣椒素类物质的含量变化。试验结果表明：烤制加热温度（80～180℃）及其时间（2～16 min）对辣椒素类物质的影响均显著（p<0.01）;不同储藏条件下,随着储藏时间的延长,野山椒中辣椒素类物质的含量均有不同程度下降。9个月后,真空包装冷藏的辣椒粉中辣椒素类物质含量降低了16.44%,非真空包装冷藏的降低了17.00%,真空包装常温储藏的降低了23.58%,非真空包装常温储藏的降低了24.11%,真空包装对其稳定性影响不大,低温更有利于保存辣椒素类物质。     

大蒜果聚糖的水解方法及其定量分析

为了建立大蒜果聚糖含量的快速高效检测方法,本试验以乐都紫皮大蒜为试材,首先通过热水、超声、超声-热水法提取大蒜总糖,分别利用不同的水解试剂类型、pH值、浓度、水解时间将其中的果聚糖彻底水解,通过响应面分析筛选了果聚糖降解的最优条件;随后利用分光光度计和高效液相法测定水解前后果聚糖降解产物(蔗糖、葡萄糖、果糖)的含量并计算差值,得到大蒜组织中所有果聚糖的总含量;最后利用方法学验证对确立的方法进行了优化和评价。结果表明,热水法更有利于提取大蒜可溶性总糖;大蒜果聚糖最佳水解工艺条件为水解温度90℃、HCl浓度3 mol·L^-1、水解时间1 h,经此条件水解后大蒜果聚糖含量预测值为627.903 mg·g^-1 FW,与实际测定值(620.470 mg·g^-1 FW)差异不显著,所得回归模型拟合良好。方法学验证结果显示,该果聚糖定量方法精密度、重复性及稳定性良好,三者的相对标准偏差(RSD)均小于1.5%;平均回收率为98.45%~101.04%,其RSD为0.59%~1.75%。利用此方法鉴定大蒜资源果聚糖性质发现,不同品种大蒜鳞茎中果聚糖含量差异显著。本研究筛选确立的检测方法准确性较高,结果可靠,适用于大蒜果聚糖含量的测定分析。本研究结果为大蒜资源果聚糖性状的深入评价和开发利用提供了理论依据。     

大豆中6种异黄酮的高效液相色谱同步测定方法研究

本文建立了大豆中大豆苷、大豆黄苷、染料木苷、大豆素、大豆黄素和染料木素6种大豆异黄酮的高效液相色谱同步测定方法.大豆样品经80％甲醇提取,用反相C18柱分离,紫外检测器检测.结果表明,6种异黄酮线性范围为0.096～4.8 μg/mL,相关系数大于0.999,在豆粕中的添加回收率在80％～120％,变异系数小于10％.利用建立的方法检测了国内400个不同品种大豆中的异黄酮含量,同时分析了发酵、膨化、浸提等不同加工工艺对大豆异黄酮含量的影响,这些数据的获得将为大豆品种的选育及不同加工工艺的大豆产品在畜禽饲料中的高效利用提供基本参数.     

不同产地黄芪饮片中多糖及甲苷含量比较

黄芪是常用补气药之一,黄芪多糖和黄芪甲苷是其发挥药效的物质基础。以黄芪多糖和黄芪甲苷为评价指标,比较甘肃、内蒙古、山西三个不同产地的黄芪饮片的质量差异。结果表明:甘肃黄芪、内蒙古黄芪、山西黄芪的多糖含量分别为22.87%、20.02% 、22.29%;甘肃黄芪的黄芪甲苷含量最高,为0.049%;其次是山西黄芪,黄芪甲苷含量为0.026%,内蒙古黄芪中黄芪甲苷含量最低,仅为0.002 7%。仅有甘肃黄芪的甲苷含量测定结果符合药典标准。分析认为药材生长年限是导致内蒙古黄芪与甘肃黄芪、山西黄芪甲苷含量之间差异较大的主要原因。该研究为黄芪种植、资源开发及合理使用提供参考依据。     

土壤中磺胺类抗生素的检测方法优化及残留、降解研究

优化了磺胺甲基嘧啶(SM1)、磺胺二甲嘧啶(SM2)、磺胺对甲氧嘧啶(SMT)、磺胺甲噁唑(SMZ)4种磺胺类抗生素的高效液相色谱(H PLC)检测方法,分析了广州市养殖场周边土壤中磺胺类抗生素的残留特征,并进行了2种磺胺类抗生素的土壤降解试验。结果表明,4种磺胺类抗生素分别在0.10~10μg ml-1范围内线性良好,相关系数R>0.99。确定了最佳提取液为甲醇:含EDTA的Mcllvain缓冲液=1∶1(V/V),4种磺胺类药物的检测限与回收率分别为2.9~4.7μg kg-1、83.6%～90.1%。广州市18个规模化养殖场周边土壤中磺胺类抗生素污染以SM2为主,含量为1.75μgkg-1,其它3种均未被检出。土壤中磺胺类抗生素的含量总体呈随培养时间而不断下降的趋势,SMZ的降解速率大于SM2。     

芽胞杆菌FJAT-28592抗真菌脂肽的研究

为研究产表面活性剂芽胞杆菌(Bacillus)的生防作用,本研究筛选了一株能够抑制尖孢镰刀菌(Fusarium oxysporum)的芽胞杆菌FJAT-28592,经16S rRNA鉴定为暹罗芽胞杆菌(Bacillus siamensis.菌株FJAT-28592的生长温度范围为25～50℃,最佳生长温度为35℃;pH 5.0～9.0,最佳pH 6.0～8.0;可在NaC1浓度为0～6％的条件下生长,最佳生长盐浓度为2％.透射电镜显示,菌株呈杆状,具有鞭毛,宽度为0.76～0.94 μm,长度为1.76～2.94 μm.暹罗芽胞杆菌FJAT-28592发酵液和提取的发酵液粗产物对尖孢镰刀菌有很好的抑菌效果.通过血平板和排油圈实验,初步认定暹罗芽胞杆菌FJAT-28592能分泌表面活性剂至发酵液.通过酸沉淀处理,甲醇和丙酮抽提,分离和收集发酵液中表面活性剂.高效液相色谱(high performance liquid chromatography,HPLC)对初步纯化的粗品与iturin A的标准品进行分析,粗品与标准品iturin A的主峰保留时间均为10.687 min,初步判断粗品含有iturinA.克隆iturinA类脂肽合成的相关基因,获得丙二酰辅酶a转酰酶(malonyl-CoA-transacylase,ituD)和4’-磷酸泛酰巯基乙胺基转移酶(4’-phosphate generic acyl cysteamine transferase,lpa-14)基因序列,得出此表面活性剂为iturinA类的脂肽.本研究为芽胞杆菌生防菌的开发,分析获得抑菌物质提供基础资料.     

超高效液相色谱-串联质谱法测定茭白中井冈霉素的残留

研究建立以超高效液相色谱-串联质谱测定茭白中井冈霉素残留量的分析方法.比较了固相萃取、液液萃取、分散固相萃取3种前处理方式对回收率的影响,对比了BEH C18和BEH HILIC两种色谱柱及不同流动相对分析结果的影响.研究并确认了最佳分析方法:取茭白样品,经甲醇提取,固相萃取净化,净化液经ACQUITY UPLC BE...     

~(137)Cs-γ辐照及5-氮杂胞苷处理毛竹种子对其实生苗甲基化水平的影响

为了研究药物和辐照对毛竹甲基化水平的影响,采用0、25、50、100、250μmol·L-1的5-氮杂胞苷和0、10、20、30、40、60、90、120 Gy的~(137)Cs-γ射线分别处理毛竹种子,并利用高效液相色谱技术,采用外标法测定实生苗叶片的甲基化水平。结果表明,5-氮杂胞苷处理毛竹种子后,甲基化水平下降,其中250μmol·L-1处理后甲基化水平为20.8%,下降最显著;低剂量的辐照处理对甲基化的影响不明显,而在高剂量的γ射线胁迫下,DNA甲基化程度下降至26.0%,达到极显著水平。本研究揭示了辐照与基因组甲基化水平间的相关性,为毛竹辐照诱变和甲基化抑制育种提供了科学依据。     

Effect of Different Nitrogen Doses on Dry Matter Ratio,Chlorophyll and Macro/Micro Nutrient Content in Sweet Herb (Stevia rebaudiana Bertoni)

With this study, the effect of different nitrogen (N) doses applied to sweet herb (0, 50, 100, 150 and 200 N kg ha^?1) on the macro/micro nutrient element content, dry matter ratio and on the chlorophyll amount in the plant leaves is examined. The research was carried out in the research and trial field of Faculty of Agriculture Agronomy department, Akdeniz University, during the 2012–2013 growing season under field conditions for 2 years with four replications according to the randomized block trial design. Chlorophyll amounts were determined and the average was obtained with three readings from each leaf by a chlorophyll meter when the plants were in the beginning of flowering. Post-harvest macro and micro nutrient elements of the sweet herb were also investigated. According to the obtained data, while the highest chlorophyll and N amounts in the leaf for both the first and second years were determined as 46.97 SPAD (Minolta Corp, NJ, USA) and 1.34 N% 44.9 SPAD, 1.42 N%, respectively, under 200 kg ha^?1 N application, the lowest chlorophyll and N amounts were determined in the control group. In addition, N application in different doses for both years increased the phosphorus (P) and potassium (K) contents and increased the microelement contents, especially in the second year. At the same time, a correlation between the chlorophyll content in the plant leaves and the N amount was determined and a linear increase was observed in the chlorophyll amount with the increased green part.     

Crop Productivity,Steviol Glycoside Yield,Nutrient Concentration and Uptake of Stevia rebaudiana Bert. under Mediterranean Field Conditions

Stevia rebaudiana Bertoni (Asteraceae Family), characterized by a high content of steviol glycosides (SG) in its leaves, represents an interesting source of non-sucrose and no-calorie sweeteners. Stevia, which is native to Paraguay, is a relatively new crop for the Mediterranean region, where it is grown as an annual or poly-annual crop. In order to assess the crop’s environmental requirements, productive performance and nutrient uptakes, a two-year field experiment was carried out in north-eastern Italy, where the species had never previously been cultivated. The aim was to evaluate the effects of important pre-harvest factors, such as cultivation site, harvest time and their reciprocal interaction, on productivity, leaf SG yield and nutrient requirements. Results showed that the timing of the harvest and the pedo-climatic conditions of the cultivation sites had a significant effect on the main biometric traits, total and leaf dry yield, SG production, macronutrient concentration and uptake.     

The effect of different nitrogen levels on yield and quality of stevia (Stevia rebaudiana bert.)

In the present work, the efficiency of different nitrogen doses (0, 50, 100, 150, and 200 kg ha^?1) on growth, yield, and quality of stevia (Stevia rebaudiana Bert.) was investigated in 2011–2013. The study was conducted in Antalya located in the Mediterranean Region of Turkey. Terra rossa type soil (LVx, FAO) characteristics of the experimental field were clay loam, with high amounts of lime (33,9%) and slightly alkaline (pH 7.7). The experiment was carried out in randomized block design with four replications. All the results were summarized as mean of three years. The highest fresh and dry biomass yields (26.75 t ha^?1 and 7.5 ha^?1, respectively) were obtained from 150 kg ha^?1 N dose and followed by 100 kg ha^?1 N dose (26.29 t ha^?1 and 7.24 ha^?1, respectively). Whereas the highest fresh and dry leaf yields (13.27 t ha^?1 and 3.82 t ha^?1, respectively) were realized in 100 kg ha^?1 N dose. Actually, all nitrogen doses gave higher biomass and leaf yields compared to the control. On the hand, major steviol glycosides (stevioside and rebaudioside A) in the leaf were not influenced by nitrogen levels. In conclusion, 100 kg ha^?1 N dose was found to be suitable for cultivation of stevia under field conditions.     

Effects of shade regimes and planting geometry on growth,yield and quality of the natural sweetener plant stevia (Stevia rebaudiana Bertoni) in north-western Himalaya

During 2008 and 2009, field experiments were conducted at the research farm of CSIR-Institute of Himalayan Bioresource Technology, Palampur, India to assess the effect of shade levels (no shade, 25% shade, 50% shade, 75% shade) and plant geometry levels [30 × 15 cm (north–south, N–S), 45 × 10 cm (N–S), 30 × 15 cm (east–west, E–W) and 45 × 10 cm (E–W)] on the growth, yield and quality of stevia. Plant development was fastest in controls and slowest in stevia plants growing at minimum light (75% shade). These plants showed delayed bud formation and flowering. Significantly, higher dry leaf yield was recorded when the crop was grown under 25% shading than under 50 and 75% shade. Total steviol glycosides content decreased with increasing shade levels. All shade levels resulted in the same leaf-to-stem ratio, which was significantly higher than that obtained under ambient light. Plant geometry significantly affected the number of leaves and leaf dry weight plant^–1. During both years, dry leaf weight was highest in the wider row spacing (45 × 10 cm) than in the narrow row spacing (30 × 15 cm). Stevia spaced at 30 × 15 cm in an E–W direction recorded significantly higher total steviol glycosides at 2 months after transplanting (MAT).     

The Effect of the Plant Age and Growth Period on the Nutritional Substance,Chlorophyll and Steviol Glycoside Rates in Stevia (Stevia Rebaudiana Bertoni) Leaves

Stevia (Stevia rebaudiana Bertoni) is a perennial and subshrub herb of the Asteraceae family, which originates from South America. Stevia has long been used as a sweetener and herbal medicine throughout the world. The most important feature of stevia is its sweetness with zero calories. This natural feature of Stevia is of utmost importance to everyone, especially those with diabetes and those who diet. In this study, samples were taken from Stevia rebaudiana plants of different ages (2, 3 and 4 years) in different growth periods (H1: 1 July, H2: 1 August, H3: 1 September and H4: 1 October) and an evaluation was made on the nutritional content values, the chlorophyll and sugar rates found in these samples according to the age and growth period of the plant. It was determined that the age of the plant and the harvesting period had an effect on the macro-micro nutritional elements, and chlorophyll and steviol glycoside rates contained in the stevia plant. In addition, as a result of correlation analysis, significant correlations were determined between the parameters measured in the plant. The results of the study demonstrated that in the cultivation of stevia, the best values were obtained from plants that were 3 years old and harvested in July.     

甜叶菊中9种甜菊醇糖苷积累与其生物合成关键基因表达量的相关性

为了研究甜叶菊中主要甜菊醇糖苷积累特点与其生物合成关键基因表达量的关系,本研究选取3个品种甜叶菊(普赛科3号、中山2号、同心)为试验材料,定期在幼苗期、营养生长期、花蕾期采收植株的上位3对叶片,采用液相色谱-质谱法(LC-MS)检测9种甜菊醇糖苷,即莱宝迪苷A、B、C、D、E、F(RA、RB、RC、RD、RE、RF)、...     

反相高效液相色谱法测定饲料级维生素B_（12）

本实验采用反相高效液相色谱法测定饲料级维生素Ｂ（１２）。该方法用Ｗａｔｅｒｓ紫外检测器，波长３６０μｍ，工作曲线相关系数０．９９９８，方法回收率９８．２１％，相对标准差０．３２。     

同时测定食品中维生素B_1和维生素B_2的高效液相色谱方法

介绍了高效液相色谱法同时测定维生素Ｂ１和维生素Ｂ２的方法，该方法色谱条件为μＢｏｎｄｐａｋＣ（１８）柱；甲醇／水４０／６０（Ｖ／Ｖ）为流动相，流速为０．８ｍＬ／ｍｉｎ；采用荧光检测器（λ（Ｅｘ）＝３６５ｎｍ，λ（Ｅｍ）＝４２５ｎｍ）．维生素Ｂ１和维生素Ｂ２的平均回收率分别为９５．５０％和９５．８２％，变异系数分别为０．３７％和０．４８％．该方法具有简单、省时、干扰小等优点，并有较高的灵敏度、准确度和宽的应用范围。     

利用高能液相色谱测定根际分泌物中的有机酸: Ⅱ. 几个测定条件的影响

Acid sulfate soils (ASS) contain considerable amounts of reduced sulfur compounds(mainly pyrite) which produce sulfuric acid upon their oxidation.ASS-derived environmental degradation widely occurs in the coastal lowlands around the world,especially in the tropical and subtropical areas.The presence of ASS iun the South China has been recognized but their distribution may be largely underestimated because the soil survey data concerning ASS are based on unreliable methods and techniques.ASS in the South China have been traditionally used for rice cultivation and this practice has been proved sustainable if appropriate improvement measures are adopted.Recently,the rapid economic growth in the region has resulted in intensified coastal development which frequently involves activities that may disturb ASS,Construction of roads,foundations and aquaculture ponds may cause the exposure of ASS to air and bring about severe environmental acidificvation.There is currently insufficient awareness of the problems among the researchers,policy-makers and land managers in the South China.More attention must be paid to the possible ASS-dervived environmental degradation in order to ensure a sustainable development of the coastal lowlands in the South China region.