薄层扫描法分析黄芪中黄芪甲苷含量

研究不同产地、不同生长期野生与栽培黄芪中黄芪甲苷含量的变化,确定其最佳采收期,为更好地开发利用黄芪资源提供理论依据。建立其分析方法,为黄芪的现代质量评价体系提供参考数据,扩大黄芪药源。采用薄层扫描法,结果表明黄芪甲苷在1.1—5.5μg范围内具有良好的线性关系,R2=0.998,n=3;平均回收率(n=3)为100.50%,RSD=2.19%。吉林省临江种植基地10月20日采收的黄芪中黄芪甲苷含量最高为1.195%,10月15日采收的黄芪甲苷含量为1.164%。不同产地的黄芪中黄芪甲苷的含量为甘肃吉林临江内蒙古黑龙江吉林长春河北。黄芪药材在贮存6个月之后的黄芪甲苷含量有所下降。该方法简便、精密度高、结果准确可靠,并确立了黄芪药材的最佳采收期为3年生10月中下旬。种植基地黄芪药材可代替野生黄芪药材使用,为黄芪药材的药用资源和深入开发利用提供了基础依据。     

HPLC法测定复方甘草合剂中甘草苷的含量

建立HPLC法测定了复方甘草合剂中甘草苷的含量.以Shim-pack CLC-DOS 150mm×4.6mm(5μm)为分析柱,乙腈-0.5 醋酸(15∶85)为流动相,流速为1.0 ml·min-1,检测波长为276nm,采用外标法定量测定.结果表明,甘草苷在5～25μg·ml-1范围内呈良好的线性关系(r=0.9998);其高、中、低3个量的平均回收率分别为99.57%、99.41%、98.76%,RSD分别为0.46%、0.72%、0.69%(n=6).本方法简便可靠,重现性好,可作为复方甘草合剂质量控制方法.     

HPLC分析刺五加叶中金丝桃苷与绿原酸含量

对刺五加叶中金丝桃苷与绿原酸进行含量测定,探讨其最佳采收期,并比较不同采收期仿生栽培品与野生品刺五加叶中主要活性成分的含量差异,利用高效液相色谱法测定仿生栽培与野生刺五加叶中金丝桃苷与绿原酸的含量。在仿生刺五加叶中,金丝桃苷与绿原酸分别在6月8日、5月19日达到最高值,含量分别为0.478%、0.899%;在野生刺五加叶中,金丝桃苷与绿原酸分别在5月29日、5月19日达到最高值,含量分别为0.156%、0.704%。仿生栽培刺五加叶与野生刺五加叶主成份含量差异显著,且仿生栽培刺五加叶主成份明显高于野生刺五加叶主成份,因此仿生栽培刺五加叶可以替代野生刺五加叶作药用。这不但为日益减少的野生资源开辟了新药源,而且为刺五加叶的进一步开发应用及质量控制奠定了基础。     

高效液相法测定牡丹皮药材中丹皮酚的含量

用高效液相色谱法测定5个产地丹皮药材的丹皮酚含量。色谱柱为菲罗门LunaC18柱(5μm,4.6mm×250mm),流动相为甲醇—水(45∶55),流速1mL/min,检测波长274nm,柱温25℃。结果表明,丹皮酚在0.432—4.32μg线性良好,相关系数r=0.9997,平均回收率为100.08%,RSD为2.85%(n=5)。丹皮酚含量按其平均值为安徽丹皮>陕西丹皮>山东丹皮>河南丹皮>重庆丹皮。该方法快速简便,结果准确可靠。     

超高效液相色谱法同时测定桦褐孔菌中三种主要化合物的含量

建立超高效液相色谱法(UPLC),测定桦褐孔菌中三种主要化合物原儿茶醛、丁香酸和(E)-4-(3,4-二羟基苯基)丁-3-烯-2-酮含量。采用UPLC法,色谱柱为CORTECS UPLC T3(2. 1mm×100mm,1. 6μm),流动相为乙腈—水(含0. 1%甲酸),柱温为40℃,流速为0. 4mL/min,进样量为1μL,检测波长为280nm。结果表明:原儿茶醛、丁香酸和(E)-4-(3,4-二羟基苯基)丁-3-烯-2-酮分别在0. 1953125—6. 25μg/m L(R2=1. 0000)、0. 1953125—6. 25μg/m L (R2=0.9998)、0. 1953125—6. 25μg/m L(R2=1. 0000)范围内线性关系良好,平均回收率(n=9)分别为98. 150%(RSD=1. 924%)、95. 787%(RSD=2. 487%)、100. 324%(RSD=1. 541%)。不同产地间的桦褐孔菌含量测定结果表明,三种化合物含量的差异较大,吉林长白山最高,俄罗斯西伯利亚次之,黑龙江大兴安岭最低。该方法操作简便、结果准确可靠、重现性好,可为桦褐孔菌的定量分析和质量评价提供科学的依据。     

顶空气相色谱法测定食品中甜蜜素含量

采用顶空气相色谱法测定食品中甜蜜素含量,探讨了气液相平衡条件及色谱条件的选择,实验结果表明甜蜜素的标准溶液在0.1-0.4μg/l范围内具有良好的线性关系,回收率为87.5%-101.8%,相对标准偏差为2.6%.     

流动注射—光度法联用测定海水中PO4-P

本法针对海水分析时严重的盐度和基体干扰,以监测的海水试样为载流,并在流动注射进样阀前流路上首次引入自制全容量阴离子交换柱,去除载流中的磷酸盐,使进入系统的载流盐度与试样一致,消除了基体干扰,并通过阴柱在线再生条件试验和工作曲线优化试验,建立了流动注射磷锑钼蓝(还原剂为抗坏血酸)光度法直接测定PO4-P浓度为Ⅰ类～Ⅳ类海水的新方法,能分辨海水类别。结果表明,在最适合条件下,该方法在PO4-P浓度5～80μg/L范围内峰高与浓度成线性关系,方法检出限为0.73μg/L,空白海水加10μg/L、30μg/L和60μg/L PO4-P标准物质连续进样,RSD分别为4.57%(n=5)、4.72%(n=4)和5.76%(n=4)。进行实际样品分析时,加标回收率为101%～102%,具有很好的准确性,与国家标准方法———磷钼蓝分光光度法比对,结果吻合,令人满意。     

真空采血管顶空气相色谱法检测水中三氯甲烷、四氯化碳

采用真空采血管顶空填充柱气相色谱法测定水中三氯甲烷和四氯化碳,结果表明,三氯甲烷在10.0～50.0μg/L,四氯化碳在0.5～4.0μg/L浓度范围内呈良好线性关系,其r值分别为0.9994和0.9998;三氯甲烷和四氯化碳RSD分别在1.64%~2.27%和1.45%~2.40%之间;加标回收率分别在97.0%~103.5%和94.0%~103.2%之间。该方法操作简单,具有较好的灵敏度和准确度,适用于水中三氯甲烷和四氯化碳的检测。     

土壤中挥发性芳香烃顶空气相色谱的测定研究

本文采用顶空-气相色谱法测定土壤中的苯、甲苯、乙苯、对二甲苯、间二甲苯、异丙苯、邻二甲苯、苯乙烯8种挥发性芳香烃。结果表明,8种挥发性芳香烃在1.23μg/L~250μg/L范围内线性关系良好,相关系数为0.9 997~0.9 998,方法检出限(LOD,S/N=3)为0.37μg/L~0.52μg/L,回收率为80.18%~114.14%,RSD为0.82%~8.96%。该方法操作简单,检出限低,且适用性强,可用于土壤中挥发性芳香烃的快速定性定量测定。     

铬酸钡分光光度法测定水中硫酸盐含量

硫酸盐是水质常规分析中重要项目之一,常用的铬酸钡分光光度法(HJ/T 342-2007)在使用中常会出现校准曲线线性不佳、差异性大,测试结果不准等问题。对标准方法的关键试验过程进行补充讲解,改进显色液过滤方式,并通过样品测试进行验证分析。结果表明,硫酸盐质量浓度在5～200mg/L范围内线性关系良好,线性相关系数r0.999,运用统计学原理对不同时间测试校准曲线进行检验,结果显示无显著性差异;实际样品精密度试验相对标准偏差(RSD,n=6)为0.47%～0.61%,加标回收率为96.5%～102.5%;标准样品测试结果在1σ以内,说明改进后的方法具有可靠的操作性和准确性。     

宁夏乌拉尔甘草地上资源的开发利用

报道了系统提取、分离宁夏乌拉尔甘草地上部分的色素类和生物黄酮类等有效成分的工艺及产品开发前景展望.最佳工艺是:料叶用95%的乙醇浸泡后,将色素类和黄酮类用石油醚分离,色素类可以制成叶绿素铜钠盐及叶黄素等,黄酮通过柱层析法制得含量大于80%的甘草叶黄酮产品.该工艺操作简单、连续,可以实现工业化生产.     

PRELIMINARY ESTIMATION OF COLD WATER AVAILABILITY IN LAKES FOR FISH HATCHERIES1

ABSTRACT: Fish hatcheiies for cold water species (e.g., salmonids) require water below a certain specified optimum temperature. Deep lakes and reservoirs, which are thermally stratified, will have cold water below the thermocline suitable for fish hatchery supplies. Proper management will require withdrawal of water at different depths and a mixture of correct proportions can yield water at desired temperatures and quality. For preliminary studies, a mathematical model can be used to show by a comparatively simple computation the effect of different withdrawal rates of cold water and to check if the situation is critical. A critical situation may warrant the application of sophisticated computer models and/or the use of chilling at the hatchery. The method is illustrated by a case study for a small lake in the Province of Nova Scotia.     

原油在盐水中的溶解度研究

为了弄清污染事故的污染程度及影响因素,对原油在盐水中的溶解度进行了研究;采用正交实验方法,选定四个主要影响因素：水温、水深度、放置时间及油膜厚度,每个因素取三个水平。实验结果表明：影响水中油浓度最显著的因素是油膜厚度,显著因素是温度和水深度,次要因素是放置时间;研究结果可为污染事故的应急水处理提供依据。     

宁夏甘草资源的保护及可持续利用对策

宁夏地道中药材甘草资源在"先开发后保护"的观念指导下造成了野生资源的极大破坏,成为制约甘草资源可持续利用的最主要障碍.阐述了宁夏甘草资源保护与可持续发展的指导思想及原则,提出了具有半干旱地区区域特点的资源保护和可持续利用对策.     

The Fish Fauna of the Doubs River Prior to Completion of the Rhine–Rhône Connection

/ The part of the Doubs River between Montbeliard and Dole (France), i.e., downstream from the confluence with the Allan River, will be affected by the Rhine- Rhone connection project. In order to improve the understanding of the Doubs ichthyofauna, aquatic environments of the Doubs were sampled by electrofishing. Fish diversity and the presence of some rheophilic species demonstrated the good ecological quality of some stretches of the Doubs. This quality was due to alternating areas with very diversified aquatic environments (riffles, islands and side-arms, backwaters) and a considerable range of flow velocities. The differences in the structure of the fish communities of the different types of aquatic environments were more qualitative (fish species) than quantitative (number of species and number of fish). However, the mean number of fish was statistically lower in the canals (Freycinet canal and channelized part of the Allan River) than in the main course and in the backwaters. The natural parts of the Doubs (unnavigable reaches) showed the most diversified environmental structure and had the most rheophilic fish communities. Thus, the rheophilic species were well represented, but they proved also the most vulnerable to river regulation. However, the most abundant fishes throughout the Doubs River were generalists with no special requirements for food sources or spawning substrate.KEY WORDS: Fish communities; Regulation; Restoration; Floodplain; Large ship canal; Doubs River     

Effects of Management Legacies on Stream Fish and Aquatic Benthic Macroinvertebrate Assemblages

Fish and benthic macroinvertebrate assemblages often provide insight on ecological conditions for guiding management actions. Unfortunately, land use and management legacies can constrain the structure of biotic communities such that they fail to reflect habitat quality. The purpose of this study was to describe patterns in fish and benthic macroinvertebrate assemblage structure, and evaluate relationships between biota and habitat characteristics in the Chariton River system of south-central Iowa, a system likely influenced by various potential management legacies (e.g., dams, chemical removal of fishes). We sampled fishes, benthic macroinvertebrates, and physical habitat from a total of 38 stream reaches in the Chariton River watershed during 2002–2005. Fish and benthic macroinvertebrate assemblages were dominated by generalist species tolerant of poor habitat quality; assemblages failed to show any apparent patterns with regard to stream size or longitudinal location within the watershed. Metrics used to summarize fish assemblages and populations [e.g., presence–absence, relative abundance, Index of Biotic Integrity for fish (IBI_F)] were not related to habitat characteristics, except that catch rates of piscivores were positively related to the depth and the amount of large wood. In contrast, family richness of benthic macroinvertebrates, richness of Ephemeroptera, Trichoptera, and Plecoptera taxa, and IBI values for benthic macroinvertebrates (IBI_BM) were positively correlated with the amount of overhanging vegetation and inversely related to the percentage of fine substrate. A long history of habitat alteration by row-crop agriculture and management legacies associated with reservoir construction has likely resulted in a fish assemblage dominated by tolerant species. Intolerant and sensitive fish species have not recolonized streams due to downstream movement barriers (i.e., dams). In contrast, aquatic insect assemblages reflected aquatic habitat, particularly the amount of overhanging vegetation and fine sediment. This research illustrates the importance of using multiple taxa for biological assessments and the need to consider management legacies when investigating responses to management and conservation actions.     

四川省城市化类型的划分

基于四川省城市化水平较低,而且城市化水平在不同地区表现出一定的差距,选取了10个反映城市化水平的指标,并建立了指标体系,对四川省1个副省级市和17个地级市进行了因子分析.根据因子得分,把四川城市化划分为均衡发展型和不均衡发展型,并提出加快四川省城市化进程的对策,力求为制定适宜的城市化对策和发展战略提供科学依据.     

Effects of channel incision on base flow stream habitats and fishes

Channel incision is a widespread phenomenon that results in stream and riparian habitat degradation. Fishes and physical habitat variables were sampled at base flow from three incised stream channels and one reference stream in northwest Mississippi, USA, to quantify incision effects on fish habitat and provide a basis for habitat rehabilitation planning and design. Incised channels were sampled in spring and autumn; the reference channel was sampled only in the autumn. Incised channel habitat quality was inferior to the reference channel despite the presence of structures designed to restore channel stability. Incised channels had physical habitat diversity levels similar to a nonincised reference channel, but contained fewer types of habitat. At base flow, incised channels were dominated by shallow, sandy habitats, moderate to high mean local Froude numbers, and had relatively little organic debris in their beds. In contrast, the reference stream had greater mean water depth, contained more woody debris, and provided more deep pool habitat. Fish assemblages in incised channels were composed of smaller fishes representing fewer species relative to the reference site. Fish species richness was directly proportional to the mean local Froude number, an indicator of the availability of pool habitat.     

A Regional‐Scale Habitat Suitability Model to Assess the Effects of Flow Reduction on Fish Assemblages in Michigan Streams1

Zorn, Troy G., Paul W. Seelbach, and Edward S. Rutherford, 2012. A Regional‐Scale Habitat Suitability Model to Assess the Effects of Flow Reduction on Fish Assemblages in Michigan Streams. Journal of the American Water Resources Association (JAWRA) 48(5): 871‐895. DOI: 10.1111/j.1752‐1688.2012.00656.x Abstract: In response to concerns over increased use and potential diversion of Michigan’s freshwater resources, and the resulting state legislative mandate, an advisory council created an integrated assessment model to determine the potential for water withdrawals to cause an adverse resource impact to fish assemblages in Michigan’s streams. As part of this effort, we developed a model to predict how fish assemblages characteristic of different stream types would change in response to decreased stream base flows. We describe model development and use in this case study. The model uses habitat suitability information (i.e., catchment size, base‐flow yield, and July mean water temperature) for over 40 fish species to predict assemblage structure in an individual river segment under a range of base‐flow reductions. By synthesizing model runs for individual fish species at representative segments for each of Michigan’s 11 ecological stream types, we developed curves describing how typical fish assemblages in each type respond to flow reduction. Each stream type‐specific, fish response curve was used to identify streamflow reduction levels resulting in adverse resource impacts to characteristic fish populations, the regulatory standard. Used together with a statewide map of stream types, our model provided a spatially comprehensive framework for evaluating impacts of flow withdrawals on biotic communities across a diverse regional landscape.     

Habitat Improvements and Fish Community Response Associated with an Agricultural Two‐Stage Ditch in Mower County,Minnesota

Water quality and stream habitat in agricultural watersheds are under greater scrutiny as hydrologic pathways are altered to increase crop production. Ditches have been traditionally constructed to remove water from agricultural lands. Little attention has been placed on alternative ditch designs that are more stable and provide greater habitat diversity for wildlife and aquatic species. In 2009, 1.89 km of a conventional drainage ditch in Mower County, Minnesota, was converted to a two‐stage ditch (TSD) with small, adjacent floodplains to mimic a natural system. Cross section surveys, conducted pre‐ and post‐construction, generally indicate a stable channel with minor adjustments over time. Vegetation surveys showed differences in species composition and biomass between the slopes and the benches, with changes ongoing. Longitudinal surveys demonstrated a 12‐fold increase in depth variability. Fish habitat quality improved with well‐sorted gravel riffles and deeper pool habitat. The biological response to improved habitat quality was investigated using a Fish Index of Biological Integrity (FIBI). Our results show higher FIBI scores post‐construction with scores more similar to natural streams. In summary, the TSD demonstrated improvements in riparian and instream habitat quality and fish communities, which showed greater fish species richness, higher percentages of gravel spawning fish, and better FIBI scores. This type of management tool could benefit ditches in other regions where gradient and geology allow.