硒(Ⅳ)-碘化物-罗丹明6G体系荧光猝灭反应测定茶叶中痕量硒

拟定了一个荧光猝灭法测定痕量硒（Ⅳ）的新方法。在盐酸介质中，硒（Ⅳ）氧化碘化钾的反应，其反应产物使罗丹明６Ｇ荧光猝灭。方法的检出限为１．２μｇ／Ｌ，线性范围为０～８０μｇ／Ｌ，方法简便快速，选择性好，用于茶叶样品中硒的测定，结果满意。     

Determination of flavonoids,flavonoid glycosides and biflavonoids inOlea europaea L. Leaves

Summary The flavonoid content of olive leaves was studied by a method based on thin-layer chromatography and recording UV spectra directly on the layer. Three flavonoid glycosides, quercitrin, rutin and luteolin-7-glycoside, one flavonoid aglycone, luteolin, and chlorogenic acid were found in olive leaves. Three compounds with a biflavonoid-type sructure have been characterized. Ten cultivars were investigated in order to indicate qualitative and quantitative differences.     

离子色谱法测定柿叶中有机酸和无机阴离子

以0．75mmol.L^-1邻苯二甲酸和0．35mmol.L^-1三羧甲基氨基甲烷的混合溶液为淋洗液，利用单柱阴离子交换色谱法，直接电导检测，对肺叶的水溶液进行了分析，检测出柿叶中主要含有机酸是琥珀酸和苹果酸，阴离子是H2PO^-4,Cl^-,NO^-3,SO^2-4。方法简便，快速。     

模拟移动床色谱提纯槲皮素

运用模拟移动床色谱分离技术 ,提取银杏叶水解物黄酮苷元中的槲皮素 ,在洗脱液配比为甲醇∶水=7∶3(体积 ) ,进样流速uF =0 1mL min ,冲洗流速uP =3 0mL min时 ,去除前杂质的洗脱流速uD =1 0mL min ,切换时间tS =9min ;去除后杂质的洗脱流速uD =0 8,L min ,切换时间tS =14min .经HPLC检测 ,产品中槲皮素质量分数达 90 %以上 .     

四合木(Tetraena mongolica Maxim)叶片的比较解剖学研究

取材于四个不同生态环境下的四合木群落，对其叶片进行比较解剖学研究，找出在不同的生态环境下四合木叶片结构的差异结论如下：四个群落中四合木叶的基本结构一致．为肉质旱生叶、叶片体积小，表皮细胞壁具不同程度的增厚，但角质层不发达，表皮外密生单细胞表皮毛，气孔为基本型，属等叶面，靠近上、下表皮均具发达的栅栏组织，且细胞由外向内渐次增大，液泡发达，同海绵组织一起构成绿色贮水组织，具不发达的叶脉，但群落Ⅲ中四合木叶片的结构与其它三个群落相比具独特性，表现在１）表皮具１～３层细胞，密度约为其它三个类型的２倍；２）气孔极度下陷；３）主脉相对发达，具有明显的机械组织；４）叶肉组织内具有丰富的含晶细胞，以上特点说明群落Ⅲ的叶片具更强的旱生特性，这一特性与其所处的生态环境的独特性相一致．     

Advanced Nanoscale Surface Characterization of CuO Nanoflowers for Significant Enhancement of Catalytic Properties

In this work, advanced nanoscale surface characterization of CuO Nanoflowers synthesized by controlled hydrothermal approach for significant enhancement of catalytic properties has been investigated. The CuO nanoflower samples were characterized by field-emission scanning electron microscopy (FE-SEM), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, high-resolution transmission electron microscopy (HR-TEM), selected-area electron diffraction (SAED), high-angular annular dark field scanning transmission electron microscopy (HAADF-STEM) with elemental mapping, energy dispersive spectroscopy (STEM-EDS) and UV–Vis spectroscopy techniques. The nanoscale analysis of the surface study of monodispersed individual CuO nanoflower confirmed the fine crystalline shaped morphology composed of ultrathin leaves, monoclinic structure and purified phase. The result of HR-TEM shows that the length of one ultrathin leaf of copper oxide nanoflower is about ~650–700 nm, base is about ~300.77 ± 30 nm and the average thickness of the tip of individual ultrathin leaf of copper oxide nanoflower is about ~10 ± 2 nm. Enhanced absorption of visible light ~850 nm and larger value of band gap energy (1.68 eV) have further supported that the as-grown material (CuO nanoflowers) is an active and well-designed surface morphology at the nanoscale level. Furthermore, significant enhancement of catalytic properties of copper oxide nanoflowers in the presence of H2O2 for the degradation of methylene blue (MB) with efficiency ~96.7% after 170 min was obtained. The results showed that the superb catalytic performance of well-fabricated CuO nanoflowers can open a new way for substantial applications of dye removal from wastewater and environment fields.     

黄树莓叶片中黄酮类物质的提取及抗氧化性

黄酮类物质具有降血糖、降血脂、抗心律失常、抗氧化高效性与低毒性、抗衰老等生理活性1 2 。从药食两种植物中筛选出高效低毒且经济的抗氧化性强的物质 ,必将是近一步开发天然高效食品抗氧化剂的重要途径[3 5] 。黄树莓是我国北方地区小浆果树种之一 ,其中以黑龙江分布较多。黄树莓的浆果甜而芳香 ,营养丰富 ,是鲜美的生食果品 ,也可加工制成果酱、果酒、果汁和蜜饯等。它又是密源植物和药用植物 ,有止渴、痰、发汗、活血的效用。本实验以测定黄树莓叶片总黄酮含量并考察了提取物粗黄酮对猪油的抗氧化性。1　实验部分1 1　主要试剂及仪…     

Studies on the Constituents of Callicarpa Formosana Rolfe

Two new naturally occurring flavonoids, 3,4′,5,7-tetramethoxyflavone and 3,3′,4′,5,7-pentamethoxyflavone, along with known compounds, 5-hydroxy-3,4′,7-trimethoxyflavone, 5-hydroxy-3,3′,4,7-tetramethoxyflavone, ursolic acid, 2α,3α-dihydroxyurs-12-en-28-oic acid, phytosterols, and phytosteryl glucosides, have been isolated and characterized from the fresh leaves of Callicarpa formosana Rolfe.     

Two New Polyoxygenated Cyclohexenes from Uvaria kweichowensis

Over the past two decades,the Uvaria genus has been found to be an important source of natural products with various structures and some of them have shown antitumour,antileukemic or antibiotic activities1,2.Our previous studies have resulted in the isolation of a series of polyoxygenated cyclohexenes from U.grandiflora,U.tonkinensis var.Subglabra3,4.To further search for active compounds from this genus,Uvaria kweichowensis,distributed in the southwest of China,was subjected to phytochemica…     

Determination of 21 organochlorine pesticides in tree leaves using solid-phase extraction clean-up cartridges

A method to determine 21 organochlorine pesticides (OCPs) in tree leaves [chestnut (Castanea sativa), hazel (Corylus avellana), oak (Quercus robur) and walnut tree (Juglans regia)] based on microwave-assisted extraction (MAE) followed by solid-phase extraction (SPE) clean-up is described. After extraction with hexane:acetone (50:50), four different sorbents (Florisil, tandem Florisil + alumina, silica and ENVI-Carb) were assayed for the clean-up step. Pesticides were eluted with 5 mL of hexane:ethyl acetate (80:20) and determined by gas chromatography and electron capture detection (GC-ECD). Carbon was the sorbent, which provided colourless eluates and chromatograms with less interferent compounds. Analytical recoveries obtained were ca. 100% for all the studied pesticides with this sorbent.