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1.
建立了高效液相色谱/光化学反应器/荧光检测器测定茶叶中黄曲霉毒素B1的方法。用乙腈水溶液(V∶V=86∶14)提取黄曲霉毒素B1,提取液经净化柱和黄曲霉毒素B1免疫亲和柱净化,高效液相色谱测定。在黄曲霉毒素B1标准溶液质量浓度为0.591~5.91μg/L时,峰面积与浓度呈现良好的线性关系,黄曲霉毒素B1的回收率为85.4%~98.9%(添加量分别为0.510μg/kg、7.090μg/kg和14.180μg/kg),相对标准偏差为0.2%~1.8%,方法检出限为0.1μg/kg。运用所建立方法对市售的8个茶样及加标样品中的黄曲霉毒素B1进行检测,结果显示该方法选择性强、灵敏度高,适合茶叶中黄曲霉毒素B1的测定。  相似文献   

2.
建立了高效液相色谱/光化学反应器/荧光检测器测定茶叶中黄曲霉毒素B1的方法。用乙腈水溶液(V∶V=86∶14)提取黄曲霉毒素B1,提取液经净化柱和黄曲霉毒素B1免疫亲和柱净化,高效液相色谱测定。在黄曲霉毒素B1标准溶液质量浓度为0.591~5.91μg/L时,峰面积与浓度呈现良好的线性关系,黄曲霉毒素B1的回收率为85.4%~98.9%(添加量分别为0.510μg/kg、7.090μg/kg和14.180μg/kg),相对标准偏差为0.2%~1.8%,方法检出限为0.1μg/kg。运用所建立方法对市售的8个茶样及加标样品中的黄曲霉毒素B1进行检测,结果显示该方法选择性强、灵敏度高,适合茶叶中黄曲霉毒素B1的测定。  相似文献   

3.
环糊精对花生黄曲霉毒素B_1荧光增强作用与应用研究   总被引:1,自引:0,他引:1  
本文探讨了一种新型无毒的黄曲霉毒素荧光增强剂—β-环糊精及其衍生物。结果表明,在2mL黄曲霉毒素B1溶液中加入1mL0.01mol/Lβ-环糊精或其衍生物时荧光增强倍数最大,其中β-环糊精可使荧光信号增强5倍,2,6-二甲基-β-环糊精荧光增强倍数可达到8倍,表明β-环糊精及其衍生物对黄曲霉毒素荧光增强作用极为显著;利用该增强剂在黄曲霉毒素荧光增强前和荧光增强后的信号变化量和黄曲霉毒素浓度之间的线性关系建立了新型荧光增强剂免疫亲和柱荧光光度检测方法,最低检出限可达0.3μg/kg,相关系数都达到0.99以上;对花生样品的添加回收率在90%~120%之间;与基于高效液相色谱国家检测标准方法比对分析,两种检测方法无显著差异,相对误差小于4%,为黄曲霉毒素高灵敏快速检测技术开辟了新的途径。  相似文献   

4.
为建立检测茯砖茶中黄曲霉毒素B1的免疫亲和净化-高效液相色谱质谱分析方法,并对20份茯砖茶样品中黄曲霉毒素B1含量进行测试.样品经过70%甲醇溶液匀浆提取,免疫亲和柱富集净化,经C18色谱柱分离后采用三重四级杆质谱检测.结果表明,HPLC-MS检测线性关系良好,方法检出限为0.03μg/kg,加标浓度2~20μg/kg...  相似文献   

5.
为测定小麦籽粒中因赤霉病产生的毒素脱氧雪腐镰刀菌烯醇(deoxynivalenol, DON)、雪腐镰刀菌烯醇(nivalenol, NIV)和玉米赤霉烯酮(zearalenone, ZEN),本研究构建了一种多功能净化柱-超高效液相色谱-二极管阵列检测器(multifunctional column-ultra performance liquid chromatography-diode array detector, MFC-UPLC-DAD)方法,可同时测定上述三种毒素,对该方法与多功能净化柱-高效液相色谱-二极管阵列检测器(multifunctional column-high performance liquid chromatography-diode array detector, MFC-HPLC-DAD)法测定9个小麦品种中上述3种毒素含量的结果进行比较;并用MFC-UPLC-DAD法检测了129份小麦品种(系)的毒素含量。结果显示,MFC-UPLC-DAD法检测三种毒素在检测范围内(0.01~10.00 μg·mL-1)标准曲线的相关系数均大于0.994;三种毒素的检出限为15~78 μg·kg-1;回收率在80.25%~118.35%之间,相对标准偏差为0.20%~1.92%;9份小麦品种中,3种毒素含量的测定结果在两种方法间差异均不显著。利用MFC-UPLC-DAD法测定自然发病的129份材料发现,DON毒素与NIV毒素检出率较高,分别为99%和92%;符合限量标准且毒素含量较低的材料共80份。本研究构建的MFC-UPLC-DAD法可同时测定小麦种DON、NIV和ZEN含量,测定结果重复性好,准确度高,可对抗赤霉病育种提供方便。  相似文献   

6.
在培养日本曲霉(Aspergillus japonicus-FCL)和黑曲霉(Aspergillus niger ATCC 20611)的过程中,研究了培养基中不同浓度的蔗糖(3~25%w/v)和蛋白胨(2~5%w/v)对曲霉的影响以探索较优配方。此外,甘蔗糖蜜(3.5~17.5%w/v总糖量)和酵母粉(1.5~5%w/v)被当作两种菌株的营养素替代品用于研究。探索这些培养基的目的是用来分析细胞生长趋、果糖基转移酶产酶和低聚果糖(FOS)产物。果糖基转移酶活性和低聚果糖产量利用高效液相色谱进行检测分析。两种菌株在3%(w/v)蔗糖和3%(w/v)蛋白胨的培养基中酶反应产物含量最高,或者在含总糖3.5%(w/v)的甘蔗糖蜜和1.5%(w/v)酵母粉的培养基中可以达到同等效果。研究表明,甘蔗糖蜜和酵母粉在酶和低聚果糖(约60%w/w)的生产中与蔗糖和蛋白胨的效果一样好。  相似文献   

7.
建立槟榔中9种有机磷农药残留的三重四级杆液相色谱-质谱联用分析方法,采用1%乙酸-乙腈溶液作为提取液,直接稀释后以液相色谱-串联质谱仪在多反应监测模式(MRM)下检测。研究结果发现,9种有机磷农药成分的线性范围均在2~20 ng/mL,相关系数r均大于0.999。方法的平均回收率在73.4%~120%,RSD为0.59%~9.93%,方法检出限为50.0 μg/kg。此方法具有良好的回收率及稳定性,可用于槟榔中有机磷农药残留的测定。  相似文献   

8.
建立了超高效液相色谱-串联质谱法测定茶园用农药制剂中烷基酚聚氧乙烯醚(APEOs)的检测方法。APEOs经Waters-BEH C18色谱柱分离,电喷雾正离子源(ESI+)条件下多反应监测模式(MRM)测定,外标法定量。APEOs(n=3~20)在水剂、水乳剂、悬浮剂、乳油、颗粒剂和可湿性粉剂中的基质标准曲线在0.047~1503.6 mg·kg-1范围内线性关系良好,相关系数(r)为0.996 1~0.999 9;在0.5~1 503.6 mg·kg-1添加范围内,添加回收率为83.8%~120.4%,相对标准偏差(RSD)为0.6%~13.7%,LOQ为0.5~150.4 mg·kg-1。测定的51种茶园农药制剂中,辛基酚聚氧乙烯醚(OPEOs)百分数含量均低于0.5%;壬基酚聚氧乙烯醚(NPEOs)质量分数为ND~32.1%,检出率90.2%,NPEOs在茶园用农药中应用普遍。  相似文献   

9.
谢丽萍 《福建茶叶》2013,35(2):8-10
建立了气相色谱法同时测定茶叶中22种有机磷农药残留的方法。样品用正己烷-乙酸乙酯(1:1,v/v)混合溶剂提取,经固相萃取小柱净化,采用CP-Sil 24 CB色谱柱分离,18MIN内在气相色谱上实现22种有机磷农药残留分析。采用外标法定量分析,在0.02~0.2μg/ml范围内线性关系良好,检出限为0.005~0.02 mg/kg,回收率为78%~120%,相对标准偏差为2.3%~7.7%。该方法简便、快速、准确、重现性好、灵敏度高,适用于实际检测。  相似文献   

10.
以海南兴隆地区的咖啡豆为试材,利用顶空固相微萃取-气相色谱-质谱法(HS-SPME/GC-MS)结合电子鼻对不同烘焙度(浅度、中度、深度)下的咖啡挥发性化合物进行检测。结果表明:烘焙咖啡中共检测出123种化合物,浅度豆检测出90种化合物,主要为酸类和吡嗪类,中度豆检测出103种化合物,主要为酮类、呋喃类、吡嗪类和吡咯类,深度豆检测出118种化合物,主要为呋喃类、吡啶类和酚类;电子鼻传感器可有效分析咖啡挥发性成分变化(除传感器LY2/g CT外),主成分分析(PCA)可有效区分不同烘焙度的咖啡香气。随着烘焙程度加深,咖啡中吡咯类、吡啶类、含硫化合物等挥发性化合物种类和相对含量逐渐增加,吡嗪类和酸类逐渐减少,呋喃类和酮类先增加后减少,进而改变咖啡的特征性香气。HS-SPME/GC-MS与电子鼻技术结合可根据挥发性物质的差异为判断指标,以较好的区分海南兴隆地区不同烘焙度咖啡,为海南兴隆咖啡的烘焙加工提供理论借鉴。  相似文献   

11.
Pasture legumes are important components of both mixed farming rotations and permanent pastures in temperate climates. Breeding of two widely sown pasture legumes, subterranean clover (Trifolium subterraneum L.) and French serradella (Ornithopus sativus Brot.), is constrained by the long generation cycle, typically enabling only one generation per year. We hypothesized manipulation of culture medium and conditions would enable the development of a laboratory‐based protocol for in vitro reproduction in subterranean clover and French serradella. In vitro flowering and viable seed set was induced from both species. For subterranean clover, the most effective treatment was culturing on modified MS medium with 1 μm kinetin and 0·1 m sucrose under a 100 μmol m?2 s?1 light intensity and continuous photoperiod. For French serradella, culture on a hormone‐free B5 medium with 5 mm NH4Cl and 0·1 m sucrose under a 100 μmol m?2 s?1 light intensity and 20 h photoperiod was optimum. It is expected this technique will have application in accelerating generation turnover within breeding programs, for the study of factors influencing flowering in pasture legumes, and for the propagation of valuable yet enfeebled plants such as embryo‐rescued hybrids.  相似文献   

12.
Marine organisms represent an excellent source of innovative compounds that have the potential for the development of new drugs. The pharmacokinetics of marine drugs has attracted increasing interest in recent decades due to its effective and potential contribution to the selection of rational dosage recommendations and the optimal use of the therapeutic arsenal. In general, pharmacokinetics studies how drugs change after administration via the processes of absorption, distribution, metabolism, and excretion (ADME). This review provides a summary of the pharmacokinetics studies of marine-derived active compounds, with a particular focus on their ADME. The pharmacokinetics of compounds derived from algae, crustaceans, sea cucumber, fungus, sea urchins, sponges, mollusks, tunicate, and bryozoan is discussed, and the pharmacokinetics data in human experiments are analyzed. In-depth characterization using pharmacokinetics is useful for obtaining information for understanding the molecular basis of pharmacological activity, for correct doses and treatment schemes selection, and for more effective drug application. Thus, an increase in pharmacokinetic research on marine-derived compounds is expected in the near future.  相似文献   

13.
Evaluation of crop and forage yield stability is of increasing relevance in the context of current and recent environmental changes but, in contrast to other field crops, there are no published systematic analyses among forage crops in Europe. A study of stability performance was conducted with 13 Czech cultivars of lucerne at four locations over a 2‐year period with the following aims: (a) to evaluate yield stability of varieties across different environments and (b) to calculate measurable benefits of variety selection in relation to the specific environment. The cultivar Vlasta was identified as the highest yielding cultivar (annual yield 16.0 t DM/ha), whereas the lowest yielding cv. Magda, Tereza and Oslava averaged around 14.9 t DM/ha. Effect of genotype × environment interaction (G × E) was two times higher than for genotype alone. Additive main effects and the multiplicative interaction (AMMI) model showed that the highest yielding cultivars may not be stable across environments. This study demonstrated further that significant yield improvement could be detected, even among a relatively homogenous group of domestic cultivars, and this was driven mainly by site productivity: the improvement was +10% in low‐yielding sites, compared with +3% in high‐yielding sites. Results highlight that advanced agronomy should also consider stability parameters such as AMMI stability value or superiority measures for forage crops in response to the challenges associated with climate change.  相似文献   

14.
Résumé Fusarium culmorum et, dans une moindre mesure,F. avenaceum, F. sambucinum, Colletotrichum coccodes etCylindrocarpon sp. ont été isolés de tubercules entreposés en atmosphère contr?lée (AC) et atteints de pourriture grave. Des expériences d'inoculation de tubercules avec 10 espèces ou variétés fongiques et conservation en AC à 8 et 10°C ont montré que: 1) les champignons non pathogènes en atmosphère normale (ex.:Cylindrocarpon sp.) le devenaient en AC, 2) ceux qui étaient faiblement pathogènes en atmosphère normale étaient nettement plus virulents en AC (ex.:F. culmorum), 3) les espèces ou variétés virulentes en conditions d'air normales (Fusarium sulphureum etPhoma exigua var.foveata) ne provoquaient pas de pourriture plus grave en AC et leur activité pouvait même être légérement freinée.
Summary The extensive rotting of tubers which occurred during storage trials in controlled atmospheres has led to a mycological and pathological study of the rots. The most frequently isolated species wasFusarium culmorum althoughF. avenaceum, F. Sambucinum, Coletotrichum coccodes and aCylindrocarpon sp. were also present. Tubers of cvs Bintje and Ulla were inoculated with 19 isolates of 10 fungal species or varieties associated with rotting of stored tubers (Table 1). The tubers were incubated at 8 or 10°C in normal or controlled (2% O2:1% CO2, 2% O2:6% CO2, 2% O2:12% CO2, 6% O2:6% CO2) atmospheres and the extent of rotting was determined a month later (Tables 2 and 3 and Fig. 2). Species which were weakly virulent in a normal atmosphere (variousFusarium spp. andPhoma exigua var.exigua) were clearly more aggressive in the controlled atmosphere and this was especially evident in the case ofF. culmorum. Species ot pathogenic in a normal atmosphere under experimental conditions (Colletotrichum coccodes, Cylindrocarpon sp.,Phoma eupyrena) caused rotting in the controlled atmosphere. The two species which were virulent in a normal atmosphere (F. sulphureum andP. exigua var.foveata) were also virulent in the controlled atmosphere and in some cases the extent of rotting was even less. As a general rule, rotting caused by weakly virulent fungi was greater in both cultivars in the controlled than in a normal atmosphere.

Zusammenfassung Eine starke F?ulnis von in Kontrotrollierter Atmosph?re gelagerten Kartoffelknollen veranlasste eine mykologische und pathologische Untersuchung. Der am h?ufigsten isolierte Pilz warFusarium culmorum. F. avenaceum, F. sambucinum, Colletotrichum coccodes undCylindrocarpon sp. wurden ebenfalls bestimmt. Neunzehn St?mme von 10 Pilzsorten oder-Arten welche bei Lagerf?ulnis vorkommen (Tab. 1) wurden auf Knollen der Sorten Bintje und Ulla inokuliert. Die Lagerung wurde bei 8 oder 10°C under Normalbedingungen oder kontrollierter Atmosph?re durchgeführt (2% O2:1% CO2, 2% O2:6% CO2, 2% O2:12% CO2, 6% O2:6% CO2). Der F?ulnisgrad (Abb. 1) wurde nach einem Monat bonitiert. Die Ergebnisse sind in den Tabellen 2 und 3 dargestellt und in der Abb. 2 illustriert. Unter in Normalbedingungen nur schwach virulente Arten (verschiedeneFusarien undPhoma exigua var. exigua) waren deutlich aktiver in kontrollierter Atmosph?re. Dies was besonders der Fall fürF. culmorum. Pilze, die im Versuch unter Normalbedingungen nicht pathogen waren (Colletotrichum coccodes, Cylindrocarpon sp., Phoma eupyrena), haben unter kontrollierter Atmosph?re Sch?den verursacht. Hingegen werden die beiden unter Normalbedingungen sehr pathogenen Arten (F. sulphureum undP., exigua var.foveata), durch kontrollierte Atmosph?re wenig beeinflusst. Es wurde sogar in einigen F?llen eine gewisse Verringerung des F?ulnisbefalls beobachtet. Ganz allgemein haben die getesteten kontrollierten Bedingungen die Entwicklung der Pilzf?ulnis an beiden Kartoffelsorten gef?rdert, speziell durch Pilzarten, welche unter Normal-bedingungen wenig Sch?den verursachen.
  相似文献   

15.
The review of the 2016–2017 marine pharmacology literature was prepared in a manner similar as the 10 prior reviews of this series. Preclinical marine pharmacology research during 2016–2017 assessed 313 marine compounds with novel pharmacology reported by a growing number of investigators from 54 countries. The peer-reviewed literature reported antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral activities for 123 marine natural products, 111 marine compounds with antidiabetic and anti-inflammatory activities as well as affecting the immune and nervous system, while in contrast 79 marine compounds displayed miscellaneous mechanisms of action which upon further investigation may contribute to several pharmacological classes. Therefore, in 2016–2017, the preclinical marine natural product pharmacology pipeline generated both novel pharmacology as well as potentially new lead compounds for the growing clinical marine pharmaceutical pipeline, and thus sustained with its contributions the global research for novel and effective therapeutic strategies for multiple disease categories.  相似文献   

16.
SUMMARY

Vitamin A, iodine, and iron deficiencies affect large numbers of people worldwide. A deficiency of one or more of these micronutrients adversely affects the physical and mental abilities of humans. South Asia contains a high percentage of these individuals, not just because of its large population, but also the prevalence of deficiency is higher there than in many other parts of the world. The reasons for the high rates of deficiency in South Asia are many, but they include inadequate availability of micronutrient-rich foods, sub-optimal dietary habits, and high rates of infection. Across the region, national plans vary from (a) increasing availability of appropriate foods, (b) introducing new dietary behaviors, (c) improving health status, and (d) directly addressing deficiency through intervention programs. The extent to which each of the countries is making progress toward the goals of these plans can help in understanding the priorities for future efforts to address micronutrient malnutrition. This article discusses the adverse effects of micronutrient deficiencies in humans with special reference to South Asia.  相似文献   

17.
东南亚、南亚地区是世界上重要的稻米产区,稻米在民众饮食生活和国家社会政治中占有重要地位,民众生活中也保存了非常悠久和丰富的稻作文化习俗及稻谷起源神话传说。本文分析了水稻在东南亚、南亚主要国家印度、印度尼西亚、泰国、越南、菲律宾、孟加拉国、缅甸的作用、地位、生产、消费、文化等情况,并指出了印度、印度尼西亚稻文化的主要标志。  相似文献   

18.
Plains rough fescue ( F estuca hallii) is an important forage grass species in western Canada. Seed for use in pastures and ecological restoration is in high demand but supply is limited because F. hallii is an erratic seed producer. Seed producers require an understanding of the factors that influence flowering and seed set in this species. The aim of this study was to assess the effect of irrigation and nitrogen fertilization on the flowering and growth of F. hallii in a native rough fescue prairie in Alberta, Canada. Irrigation had a strong positive effect on seedhead density, whereas fertilization had limited effects on growth and reproduction of F. hallii. These results demonstrate that under field conditions, available moisture is likely to be a key factor driving flowering and seed production in F. hallii.  相似文献   

19.
Summary

Within the last three decades, the rice-wheat cropping system has triggered, and with time, aggravated soil micronutrient deficiencies in the Indo-Gangetic Plains (IGP). This has largely been due to the shift from an earlier rice and wheat monoculture with low yielding, long duration indigenous varieties, to an intensive rice-wheat rotation cropping system with short duration modern high yielding varieties on the same piece of land. The problems related to micronutrient deficiency in the IGP are more due to the size of its available pools in the soil rather than its total contents and are greatly influenced by crop management, or rather its mismanagement. Deficiency of zinc is widespread in the IGP, but with the extensive use of zinc sulfate, zinc deficiency has reduced in some areas of the region. Meanwhile, the deficiency of Fe, Mn and B has increased in the IGP. Deficiency of Cu and Mo is location specific and can limit rice and wheat yields. The adoption and spread of the rice-wheat system in permeable coarse textured soils, particularly in the western IGP, not only caused iron deficiency in rice but also resulted in the emergence of manganese deficiency in wheat. In highly calcareous and acidic soils, boron is the next limiting micronutrient in crop production after zinc. Bumper rice and wheat harvests in the past decade, the declining use of organic manures in the region and except for the widespread use of zinc sulfate, a general lack of awareness amongst farmers on micronutrient deficiency problems has contributed to micronutrients limiting rice and wheat yields in the IGP. Approaches to alleviating micronutrient deficiencies include matching the crop removals of the micronutrients with its replenishments through their respective external carriers, supplementation through organic sources and mobilization/utilization through cultivation of micronutrient efficient crop cultivars. Identification of efficient micronutrient carriers and finding the optimum rate, mode and time of its application is important in ameliorating the micronutrient deficiencies. This article reviews the extent of micronutrient deficiency and discusses various management options available to reduce micronutrient deficiency induced crop yield reduction for rice and wheat in the Indo-Gangetic Plains.  相似文献   

20.
A general model of crop yield response to herbicide application is proposed. The model includes three components: the effect of herbicide dosage on weed density, the effect of surviving weed density on crop yield and the effect of herbicide directly on the crop. The model is used to estimate the response of wheat yield to application of diclofop-methyl to control ryegrass (Lolium rigidum) in Australia. It is found that the competitiveness of ryegrass plants surviving treatment is reduced by the treatment and that the proportion of yield loss at a given ryegrass density is not independent of the absolute weed-free yield. The response function is used to calculate economic thresholds and optimal herbicide dosages.  相似文献   

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