Visual recognition of melamine in milk via selective metallo-hydrogel formation

A novel protocol allowing convenient and highly selective visual recognition of melamine in raw milk via selective metallo-hydrogel formation at a concentration as low as 10 ppm without any tedious pretreatment has been developed.     

Extensive Studies on the AlEt3/THF-Promoted Diastereoselec-tive Tandem Rearrangement/Reduction of a-Hydroxy (Amino) Heterocyclopropane: An Efficient Approach to 2-Quaternary 1,3-Diheteroatom Units

Introduction Diastereoselective construction of 1,3-diheteroatom units, especially 1,3-amino alcohols and 1,3-diols, has always been in high demands in synthetic organic chemistry, as they are widely present in many natural products and potent drugs, such as nucleoside antibiot-ics and the HIV protease inhibitors.1,2 They have also been used as chiral ligands for asymmetric catalysts and as synthetic intermediates.3 Although several methods for the construction of 1,3-amino alcohols have been…     

Preparation of Europium Induced Conformation—specific anti—calmodulin Monoclonal Antibody

Monoclonal antibody technique was employed to detect the conformational difference of CaM induced by metal ions. A trivalent europium ion induced conformation-specific anti-calmodulin monoclonal antibody was successfully prepared with europium-saturated calmodulin as antigen.     

偏最小二乘光度法同时测定多种酚的研究及应用

利用Ｃｕ（Ⅱ）吡啶能与酚形成稳定的三元配合物的特点，研究了Ｃｕ（Ⅱ）－吡啶－酚三元显色新体系，并以偏最小二乘法建立模型预测，同时测定了模拟水样和环境水样中的对苯二酚、间苯二酚、邻苯三酚和对硝基苯酚，取得满意效果。     

氨-碘酸盐介质中白喉类毒素的平行催化氢波

在 0 .4mol/LNH3 NH4Cl (pH 8.3 1 )介质中 ,白喉类毒素 (DT)于 - 1 .89V(vs.SCE)处产生的极谱催化氢波可被碘酸钾进一步催化 ,峰电流明显增大 ,但峰电位不变 ,产生一种氢的新动力波 ,建议称其为平行催化氢波。在 0 .4mol/LNH3 NH4Cl(pH 8.3 1 ) - 5 .0× 1 0 - 3 mol/LKIO3介质中 ,DT平行催化氢波的二阶导数峰电流与其浓度在 0 .2 μg/mL～ 1 .0 μg/mL内呈线性关系 ,可用于生物制品中DT含量的测定。     

锡铅银等低熔点合金中氧的测定方法研究

研究了锡铅银等低熔点合金中杂质氧的测定方法。针对这些金属高温下易挥发、分解的特点，选择适宜的加热温度，使用铜和石墨粉作为浴料，选择标准坩埚，以电流920A加热进行试验。对氧的质量分数为0.017%的试样，分析精密度为5.9%，加标回收率为91％－108％。     

反应挤出法合成S/B多嵌段共聚物的研究

在阴离子引发体系下 ,以双螺杆挤出机为反应器 ,采用丁二烯、苯乙烯混和单体加料方式 ,本体法一步合成了S B多嵌段共聚物 .考察了螺杆转速、进料速率以及不同丁苯配比对反应挤出合成PS及S B嵌段共聚物聚合转化率的影响 .用1 H NMR、IR、DMA、TEM等方法对S B嵌段共聚物进行了表征 ,结果表明共聚物由多个微小的丁二烯嵌段和少量无规段组成 .当丁二烯含量少至 15 %左右时 ,其嵌段可回缩成球状 ,粒径大约在 30～ 5 0nm .该材料的韧性随着共聚物中丁二烯含量的增加而逐渐提高 ,特别是断裂延伸率的提高尤为显著     

SYNTHESIS OF THE POLYSTYRENE-TYPE ADSORBENTS CONTAINING POLAR GROUPS AND THEIR CAPACITIES IN THE ADSORPTION OF STEVIOSIDE AND GYPENOSIDES

Seven polystyrene-type adsorbents (Ⅰ—Ⅶ) were synthesized by the modification of styrene-divinylbenzene copolymer respectively with hydroxymethyl, aminomethyl, methoxymethyl, phenoxymethyl, (4-hydroxy phenoxy)methyl, (4-acetylphenoxy)methyl, and acetyl groups. Their structures were characterized with chemical methods and physical techniques. The adsorption capacities of the adsorbents to stevioside and gypenosides were determined via batch test in which the HPLC method was used for the analysis of Saponin concentration of solution. The results showed that all the adsorbents could adsorb these saponins to a certain extent, but Ⅵ and Ⅶ had large capacities owing to their moderate polarities.     

哌仑西平的单扫描示波极谱法测定

本报道一种测定哌仑西平的单扫描示波极谱法，在０．１ｍｏｌ／ＬＮＨ４Ｃｌ－ＮＨ３．Ｈ２Ｏ（ｐＨ８．０±０．１）缓冲液中，哌仑西平有一极谱还原波，其峰电位为－１．５１Ｖ（ｖｓ．ＳＣＥ），其一阶导数峰高与哌仑西闰浓度在６．６×１０＾－７－４．６×１０＾－６ｍｏｌ／Ｌ（ｒ＝０．９９８１）和６．６×１０＾－６－１．６×１０＾－５ｍｏｌ／Ｌ（ｒ＝０．９９９１）范围内有线性关系，检测限为３．４×１０－７ｍｏｌ     

Electrodeposition and stripping process by long optical pathlength potential-step transmission chronoabsorptometry

Based on the transmittance-averaged rather than absorbance-averaged model of long optical pathlength transmission spectroelectrochemistry, a reasonable theoretical model for potential-step electrodeposition and stripping process has been developed. It can accurately predict the stripping-chronoabsorptometric waveform with a peak absorbance with respect to the time rather than that with no peak but only a theoretical maximum absorbance at the initial stage of the stripping process. Cu(II) in NH(3) . H(2)ONH(4)Cl supporting electrolyte is utilized to verify the theory. With this anodic stripping spectroelectrochemical method, a detection limit of ca 0.01mM without stirring or ca 0.002mM under stirring during deposition can be achieved. An application in the analysis of copper in practical samples is presented.