TLC法测定几种植物中熊果酸的含量

采用薄层扫描法对车前草、夏枯草、山茱萸中熊果酸的含量进行了测定, 其TLC测定条件为用环己烷-氯仿-乙酸乙酯(20 5 8) 作展开剂; 用10%H2SO4乙酸溶液作显色剂。测定结果表明: 3种植物中, 以夏枯草的熊果酸含量最高, 达0 812 %, 车前草的熊果酸含量最低, 为0 516 %, 前者是后者的1 57倍。该方法简便、快速、准确、可靠, 回收率高达96 1 %。     

双波长薄层扫描法测定楤木不同药用部位齐墩果酸的含量

采用薄层扫描法测定楤木根皮、茎、茎皮、带皮茎中齐墩果酸的含量，比较各部位齐墩果酸含量，确定最佳药用部位，齐墩果酸在1－5μg范围内线性关系良好，r=0．9999，平均回收率为98．13％。结果：根皮、茎皮齐墩果酸含量最高。     

TLC法测定虎杖中白藜芦醇的含量

本文建立了虎杖白藜芦醇含量测定的薄层扫描分析方法：以硅胶G为薄层吸附荆，氯仿：丙酮：乙酸：水(4：4：0．5：0．2)为展开剂，在紫外灯(365nm)下观察荧光斑点，在365n／n处并进行扫描测定，线性方程为：Y=(13．826S’10^-6)-0．8698(Y为白藜芦醇浓度ug／ml，S为峰面积)。并对虎杖茎、根、叶进行了含量测定。结果表明：用TIC法测定虎杖中白藜芦醇含量方法简便、快捷、准确度高、重复性好。虎杖鲜根茎中含量达0．548％。     

毛竹笋体蛋白质中氨基酸含量的薄层色谱法的研究

本文研究了毛竹笋体含量较多的4种氨基酸的薄层色谱行为及分离的最佳条件，并建立了相应的定性鉴定方法。     

双波长薄层扫描法测定木不同药用部位齐墩果酸的含量

采用薄层扫描法测定木根皮、茎、茎皮、带皮茎中齐墩果酸的含量,比较各部位齐墩果酸含量,确定最佳药用部位。齐墩果酸在1～5μg范围内线性关系良好,r=0.9999,平均回收率为98.13%。结果:根皮、茎皮齐墩果酸含量最高。     

DNS法测定红松松塔多糖含量的研究

为建立红松松塔多糖含量测定方法。应用DNS法分别测定还原糖及水解后总糖的含量,计算得出多糖含量。结果表明,以葡萄糖为对照品,此方法在20～67mg/L浓度范围内线性关系良好,回归方程A=18.7C-0.2232(R2=0.9993),平均加样回收率99.47%,RSD=1.68%。此法稳定性、重现性、精密度等均在规定范围内,过程简单,操作简便,可快速得出结果。     

沙棘叶与几种植物叶中黄酮含量的测定

以沙棘叶、黄芪叶、山楂叶、银杏叶为试验材料，采用水提方式，浸提这4种植物叶中总黄酮，浸提出黄酮量利用分光光度计检测。结果表明，沙棘叶资源丰富，是潜在可利用的天然资源，试验结果为有效利用和评价沙棘叶品质提供了科学的依据。     

石墨炉原子吸收光谱法测定样品中微量金含量分析

在样品微量金含量测定中检测方法很多,石墨炉原子吸收光谱法因其检出限高、准确度高、检测迅速等优点得到了广泛应用.在全面了解石墨炉原子吸收光谱法的基础上,通过具体实验分析,获取了准确的实验结果,希望能够推进我国微量金含量测定方法和技术水平的提升.     

不同采集期的毛果芍药根中芍药甙含量测定

采用甲醇渗滤提取，双波长薄层扫描法测定不同采集期的毛果芍药根中芍药甙的百分含量。芍药甙的含量在5月初花期最高，而相当于鲜根中的成分含量（成分产量）在9月至翌年3月份维持在最高水平。又综合分析了4个自变量，3个因变量，发现毛果芍药根中芍药甙的含量主要受其植物内部自身生长发育规律的制约，而气温、降雨量等外部因素对其影响占次要地位。     

普鲁士兰法测定胡杨中植物多酚含量

首次采用普鲁士兰法对胡杨中植物多酚含量进行了研究.取胡杨枝粉碎后过40目筛,用丙酮水溶液提取液在45℃下浸提,提取液处理后用P-B法进行测定.首先从稳定性、最大吸收波长、线性关系、重复性和准确性等角度对P-B法进行了方法改进和验证.然后用改进的P-B法对胡杨枝提取液进行测定,测得结果是胡杨枝中总酚含量平均为1.191%、RSD为2.840%.     

几种花卉植物体营养含量分析研究

1999～2000年,根据物候期分6次测定了月季、西洋杜鹃、冬珊瑚、南洋杉、马拉巴栗、广东万年青、龟背竹年周期内植物体营养元素含量.植物体中许多元素含量因物候期而异,而且类间差异明显,由高至低依次为观花果花卉、木本观叶花卉、草本观叶花卉.据此提出了参试花卉施肥配方基本比例与调整意见.     

Wood Moisture Content Measurement by X-Ray Exposure Method

lNTRoDUCTIONTheon-sitcnon-dcstructit'cmcasurcl11cntofu.oodmoisbocontcntattTactsgrcatintcrcsts.Itpla3'simpor-tantpartsinthescicntificrcscarchsucl1asonthchcatandmasstransportproccssesint"ooddri'ing.thcim-pregnationofliquidinxt'ood.thcmoisturccontcntdistri-b…     

Tartaric acid catalyzed furfurylation of beech wood

European beech (Fagus sylvatica L.) is a major tree species of European forest which is underexploited because of its low dimensional stability and durability. Similarly to what has been developed with radiata pine, furfurylation might be the answer to optimize the utilization of local beech wood. Beech wood furfurylation process was studied using five different catalysts: maleic anhydride, maleic acid, citric acid, itaconic acid, and tartaric acid. Optimization of the furfurylation process was investigated for different catalyst and furfuryl alcohol (FA) contents, and different duration of polymerization. The following properties were studied: weight percent gain (WPG), leachability, anti-swelling efficiency (ASE), wettability, modulus of elasticity, modulus of rupture, Brinell hardness, and decay durability. Tartaric acid, never investigated up to now, was retained as catalyst to perform furfurylation due to its efficacy compared to other catalysts and its novelty. Wood modification with FA and tartaric acid as catalyst led to samples with high WPG even after leaching, improved ASE, and lower wettability with water. Increasing the polymerization duration increased the fixation of FA in treated wood. Most of all, treatment gave a significant improvement in mechanical properties and resistance to wood decaying fungi.     

对几种传统植物汉名的订正

为传承中华优秀传统文化,防止宝贵植物学历史遗产的迷失,在对古籍记载的几种传统植物进行全面考证的基础上,对被近现代植物学专著张冠李戴的传统植物名称进行订正,以免以假乱真,以便正本清源。     

Lamellation in the S2 layer of softwood tracheids as demonstrated by scanning transmission electron microscopy

Summary Ultrathin cross sections of the tracheid wall in black spruce and silver fir have been examined at high resolution by scanning transmission electron microscopy (STEM) and by conventional transmission electron microscopy (TEM). For both softwoods, lamellation of the S2 layer was evident but the lamellae were seen more clearly in the STEM photomicrographs. The interlamellar distance was 7.1 nm in the case of spruce and 8.4 nm for silver fir.     

Fast measurement of starch content in cold-treated seedlings by infrared spectra

Despite the importance of starch for tree growth, methodological challenges in starch analysis slow down the research on its ecological importance. In this study, a rapid monitoring method was developed for measuring starch content in Pinus taeda L. seedlings after cold treatments. A linear mixed-effects model was used to analyze the effects of cold treatments, seedling tissue types and their interaction on starch content. Mid-infrared (MIR) and near-infrared (NIR) spectra were surveyed, and the results were analyzed using partial least squares regression to determine the starch content. The determination coefficient for calibration and residual predictive deviation were compared between MIR and NIR models to assess the variability of the established models. The results showed that the effects of cold treatments, seedling tissue types and their interaction on starch content were significant. Compared to MIR spectra, NIR spectra is more suitable to estimate starch content in the seedlings. Using NIR spectra, roots provided the most accurate estimates of starch content. The presented guidelines regarding data accuracy as a function of MIR/NIR spectra of samples represent an important methodological reference for starch quantification, which will improve the understanding of the fundamental role of starch in seedlings against environmental forces.     

Rosmarinic acid content and RAPD analysis of in vitro regenerated basil (Ocimum americanum) plants

Various in vitro cultures were established from shoot tips of Ocimum americanum seedlings. Rosmarinic acid content of the in vitro produced plants as well as parent plant were determined by HPLC analysis and subjected to RAPD analysis. MS medium with BA at a concentration of 1 mg/l and 0.25 mg/l IAA supports maximum rosmarinic acid production in plants produced from cultures grown on that medium. RAPD analysis revealed 64 scorable bands from four primers, including six polymorphic bands. The band pattern revealed differences between the parent plant and the in vitro regenerated plants. Certain band changes were found in O. americanum plants regenerated in vitro, suggesting the existence of genetic variation that might affect the biochemical synthesis of plants derived from tissue culture.     

Estimation of the sulfur ester content of cellulose nanocrystals prepared by sulfuric acid hydrolysis: a reproducible and fast infrared method

A fast and reproducible method for estimating the sulfur ester content of cellulose nanocrystals (CNCs) prepared by a pilot plant (Alberta Innovates Technology Futures—Alberta, Canada) is discussed. CNCs from sulfuric acid hydrolysis form electrostatically stabilized suspensions because of the introduction of sulfate ester groups onto the surface of the crystallites during the chemical production. The surface charge of the crystals and indirectly the sulfur ester content has implications when considering several applications. In the past, tedious and time-consuming methods such as X-ray photoelectron spectroscopy, X-ray diffraction, and elemental analysis have been used to estimate the sulfur content of CNCs. As of late, conductometric titrations have surpassed these techniques for estimating the sulfur content of CNC. In this communication, a technique is explored that is specific, fast, and reproducible across a number of samples for determining the quantity of C–O–S linkages in CNC samples. The method is based on integrating key peaks characteristic of sulfur functionalities obtained via Fourier transform infrared spectroscopy. The samples were analyzed as obtained, and no time was needed for extra sample cleanup prior to analysis. Finally, good correlation was obtained between the results obtained for the different samples and comparable to the results obtained from the widely used conductometric method.