吸附剂对柱色谱法分离荧光黄和碱性湖蓝BB效果的影响

吸附剂是影响柱色谱分离效果的重要因素,研究了几种常见的吸附剂如硅胶、碱性氧化铝、中性氧化铝、酸性氧化铝等对柱色谱法分离荧光黄和碱性湖蓝BB分离效果的影响,利用NH3-TPD及N2吸附-脱附分别表征了吸附剂的酸分布及孔分布,采用密度泛函方法计算了荧光黄和碱性湖蓝BB分子的尺寸,并分析了吸附剂酸性、结构与分离效果的关系。实验结果显示硅胶的分离效果好于氧化铝。并且,用硅胶作吸附剂时荧光黄先被洗脱,与氧化铝作吸附剂的洗脱顺序相反。实验过程有利于学生理解吸附剂的作用,加深对柱色谱法的理解,培养严谨、认真的科学态度,提高分析问题解决问题的能力,具有重要意义。     

腐植酸类物质应用研究进展

腐植酸作为一种资源广泛存在于自然界中,它是影响环境生态平衡的重要因素,也是潜在的、可大力开发和综合利用的有机资源.腐植酸类物质具有多种活性官能团,具有酸性、亲水性、界面活性、阳离子交换能力、络合作用及吸附分散能力.本文对腐植酸进行了分类,综述了其应用领域以及腐植酸类物质应用中存在的问题和应用前景.     

饲料及体重对大黄鱼排氨率影响的初步研究

以大黄鱼为研究对象，进行了饲料和体重对其氨氮排泄率影响的实验．研究结果表明，大黄鱼的排氨率受饲料影响显著，投喂配合饲料的排氨率约为投喂杂鱼饲料的2倍，两者存在显著差异（P〈0．05）．投喂配合饲料的平均排氨率分别达到5．82±0．94mg·（h·kg）^-1（116．7g）、4．80±0．48mg·（h·kg）^-1（204．9g）、3．43±0．53mg·（h·kg）^-1（313．5g），而投喂杂鱼饲料的平均排氨率分别只有3．16±0．20mg·（h·kg）^-1（116．7g）、2．41±0．18mg·（h·kg）^-1（204．9g）、1．93±0．11mg·（h·kg）^-1（313．5g）；大黄鱼排氨率同样受体重影响，并且随着体重的增加排氨率减少，二者的关系式分别为线性方程：U=-0．006 1W＋3．798（R^2=0．8963）（杂鱼饲料）和U=-0．012 1W＋7．251（R^2=0．7527）（配合饲料）．     

氯酸钾－二甲基黄－钒（Ⅴ）体系催化光度法测定痕量钒

本文研究了氯酸钾－二甲基黄－钒（Ⅴ）体系催化光度法测定痕量钒的条件及应用。钒含量在０～６０ｎｇ／１０ｍＬ范围内与ｌｇ（Ａ＿０／Ａ）有良好的线性关系，检出限１．０×１０￣（－１１）ｇ／ｍＬ。方法简便快速，应用于水及食品中痕量钒测定，结果满意。     

Gas chromatographic determination of isocitric and malic acid in the presence of a large excess of citric acid

Derivatization yields of different esters (methyl, ethyl, n-propyl, isopropyl, n-butyl and isobutyl) of citric, malic and isocitric acids with various acylating agents, such as acetic anhydride, propionic anhydride, trifluoroacetic anhydride and heptafluorobutyric anhydride, were investigated. The formation of acylated malic and isocitric acid esters is rapid and quantitative whereas the acylation of citric acid esters was slow and partial in most instances. It was found that selective analytical conditions can be achieved with the O-heptafluorobutyryl n-butyl esters. The analytical applicability of the separation and determination of the malic, isocitric and citric acid contents of model solutions and of pressed lemon juice is discussed. Concentrations of 1.2 × 10^?3 ?9.0 × 10^?3g per 100 g of isocitric acid and 4.2 × 10^?3 ?3.5 × 10^?2 g per 100 g of malic acid in the presence of 9.3 × 10^?1 g per 100 g of citric acid were measured with relative standard deviations of 7.5 and 4.2%, respectively.     

反相高效液相色谱法同时测定果汁中8种添加剂

建立了反相高效液相色谱法（ＲＰ－ＨＰＬＣ）同时直接测定进口果汁中柠檬黄和苋菜红等８种添加剂含量的方法。色谱柱为Ｈｙｐｅｒｓｉｌ　ＢＤＳ　Ｃ１８柱（２５０ｍｍ×４．０ｍｍｉ．ｄ,５μｍ）,流动相为甲醇／０．０１ｍｏｌ／Ｌ乙酸铵,梯度洗脱,流速为 １．０ ｍＬ／ｍｉｎ,柱温为 ４０℃,ＤＡＤ紫外检测器波长为 ２３０ ｎｍ。在此色谱条件下,各组分在１０ ｍｉｎ内均得到良好分离。平均回收率为 ９０％～１１４％,相对标准偏差 １．３％～８．０％。     

PAR-吖啶黄能量转移荧光猝灭法测定痕量铁(Ⅱ)的研究

对 4 (2 吡啶偶氮 ) 间苯二酚 (PAR)与吖啶黄间荧光能量转移进行了探讨 ,研究了其能量转移的最佳条件 ,并应用该体系测定痕量铁 (Ⅱ ) ,由此建立了能量转移荧光测定痕量铁的新方法。在λex/em =46 5nm/5 0 5nm ,十二烷基硫酸钠 (SDS)作用下 ,pH =9 2时 ,吖啶黄与PAR 铁 (Ⅱ )络合物间能发生有效能量转移 ,使吖啶黄的荧光猝灭。铁的量在 0～ 10 μg·L-1范围内呈良好的线性关系。最低检出限 0 0 6 μg·L-1。该方法用于水样、发样中痕量铁的测定 ,结果满意。     

乙醇敏化钛黄与蛋白质作用的共振光散射光谱研究及其分析应用

研究了在乙醇存在下钛黄（TY）与蛋白质作用的共振光散射（RLS）光谱特征 。基于RLS的增强,建立了一种测定蛋白质的新方法。考察了各种影响因素,在优 化条件下确定了RLS强度与蛋白质浓度之间的关系。当TY浓度为4 * 10~(-5)mol· L~(-1)时,牛血清白蛋白（BSA）、人血清白蛋白（HSA）和溶菌酶(lysozyme)的线 性响应范围分别为0.1～6.0 μg·mL~(-1), 0.1～5.0 μg·mL~(-1), 0.2～3.0 μg·mL~(-1),检出限分别为12.7 ng·mL~(-1), 11.6 ng·mL~(-1)和18.8 ng· mL~(-1)。三种合成样品五次平行测定的回收率和相对标准偏差（RSD）分别为96. 0%～102.3%和0.8%～3.2%。将该方法与经典的Bradford方法分别用于人血清试样中 蛋白的测定,两种方法的分析结果经F-检验和双总体T-检验证明无显著性差异。     

Raman Spectrum of Vanadium-Zirconia Yellow Pigment

Monoclinic vanadium-zirconia yellow pigments were prepared by gelling mixtures of zirconium n-propoxide and vanadyl acetylacetone. The nature of interactions between the host ion and the foreign cation in the vanadium-zirconia pigment was investigated in order to contribute to a better understanding of the origin of this pigmenting system using Raman scattering measurements. The Raman spectra of powdered samples of the vanadium-zirconia pigment recorded between 100 and 1400 cm^?1 show the peaks at 991, 701, and 403 cm^?1 assigned to the asymmetric and symmetric stretching and bending vibrations of the V⁴⁺ = O bonds, respectively. The assignment of these peaks was discussed by comparison with Raman spectra of vanadium oxides and on the basis of V-O bond distances deduced from the Hardcastle and Wachs equation and from the valence state of the vanadium cation calculated by Brown in the valence sum rule. This suggests that the V⁴⁺ cations replace Zr⁴⁺ in sevenfold coordinated site in the monoclinic zirconia structure. The V⁴⁺ cation allowing the d-d electronic transition is related to the origin of the lemon yellow coloration.     

Removal of organic dye pollutants from wastewater by electrochemical oxidation

The removal of chemical oxygen demand (COD) and color from simulated dye wastewater containing organic dyes, direct yellow 4, C₂₆H₂₀N₄O₈S₂Na₂ and acid yellow 17, C₁₆H₁₀O₇N₄S₂Cl₂Na₂ experimentally investigated using an electrochemical undivided cell reactor with Pt as anode and steel as cathode. Particular attention was paid to probe the effect of supporting electrolyte (NH₄Cl), cell voltage, pH, and treatment time on the electrochemical treatment efficiency. Experiments were also carried out using 0.2?M NH₄Cl as supporting electrolyte under the condition of free pH. The experimental results showed that the process could efficiently remove the color and COD from simulated dye waste water. The overall COD removal reached at 69.9% by using supporting electrolyte and increasing voltage. The process can be described by pseudo first-order kinetics for the removal of COD.