高效液相色谱法测定荧光增白剂OB

本文建立了高效液相色谱测定荧光增白剂ＯＢ，即２，５—双（５—叔丁基—２—苯并唑基）噻吩的方法。采用ＹＷＧＣ１８色谱柱，四氢呋喃—水（６７：３３Ｖ／Ｖ）为流动相，流速１．０ｍＬ／ｍｉｎ，紫外检测波长３６０ｎｍ，柱温４０℃，分离时间少于１１ｍｉｎ。应用于工业产品的测定，结果满意。     

高效液相色谱法测定2-氨基萘-6-磺酰甲胺及其杂质

研究了一种同时测定２－氨基萘－６－磺酰甲胺及其杂质（２－氨基萘,２－乙酰氨基萘－６磺酸,２－氨基萘－６－磺酸和２－乙酰氨基萘－６－磺酰甲胺）含量的高效液相色谱法。采用ＨｙｐｅｒｓｉｌＢＤＳ Ｃ１８色谱柱,０．２％四丁基铵高氯酸盐（ＴＢＡＰＣ）／乙腈／３６％乙酸（６０：３８：２,Ｖ／Ｖ／Ｖ）为流动相,柱温３０℃,在流速为１ｍＬ／ｍｉｎ时,上述５种物质在２０ｍｉｎ内实现了基线分离。本方法快速、准确,适     

柱前衍生反相高效液相色谱分离和测定氨基酸：用N—羟基琥珀酰？…

以Ｎ－羟基琥珀酰亚胺－α－萘乙酸酯（ＳＩＮＡ）为氨基酸的柱前衍生试剂,反相高效液相色谱分离测定了１５种氨基酸。采用含１０ｍｍｏｌ／Ｌ ｐＨ５．０的乙酸－乙酸钠缓冲溶液的甲醇－乙酸乙酯－水（１０／２／８８,Ｖ／Ｖ／Ｖ）溶液为流动相体系。分离测定了７种氨基酸;用甲醇－乙酸乙酯－水（２６／２／７７,Ｖ／Ｖ／Ｖ）分离测定了５种氨基酸;用甲醇－乙酸乙酯－水（４５／２／５３,Ｖ／Ｖ／Ｖ）分离测定了３种氨基酸。     

1─（2─吡啶偶氮）─2─萘酚─6─磺酸衍生化反相高效液相色谱法测定铁、钴、镍

本文研究了水溶性试剂１－（２－吡啶偶氮）－２－萘酚－６－磺酸（ＰＡＮ－Ｓ）与铁（Ⅱ）、钴（Ⅱ）和镍（Ⅱ）之螯合物的衍生和液相色谱分离条件。在Ｎｏｖａ－ＰａｋＴＭＣ１８柱上，用含１０ｍｍｏｌ／Ｌ的ｐＨ５．０的醋酸－醋酸钠缓冲溶液的甲醇－水溶液（５０：５０，Ｖ／Ｖ）作流动相，溴化四丁基铵（ＴＢＡ·Ｂｒ）作离子对试剂，流动相流速为１．０ｍＬ／ｍｉｎ，在５５０ｎｍ波长处进行光度检测。在Ⅱｍｉｎ内用高效液相色谱分离测定了Ｆｅ（Ⅱ）、Ｃｏ（Ⅱ）和Ｎｉ（Ⅱ）与ＰＡＮ—Ｓ的螯合物，提出了离子对反相高效液相色谱快速分离测定痕量铁、钴、镍的新方法。信噪比（ＳＮＲ）为２时，检测下限分别为０．０４３、０．００７和０．０１２ｍｇ／Ｌ。     

1-(2-噻唑偶氮)-2-萘酚螯合物反相高效液相色谱法分离测定铜(Ⅱ)、铁(Ⅱ)和镍(Ⅱ)

以１－（２－噻唑偶氮）－２－萘酚（ＴＡＮ）作柱前显色剂，于ＯＤＳ柱上，用内含０．１ｍｏｌ／ＬＬｉＣｌ，５×１０－６ｍｏｌ／Ｌ ＴＡＮ和ＨＡｃ－ＮＨ４Ａｃ缓冲溶液（ｐＨ ５．５）的甲醇－水溶液（８０：２０，Ｖ／Ｖ）作流动相，流速为０．６ｍＬ／ｍｉｎ，并以紫外－可见检测器于５９０ｎｍ处进行检测，发展了一种ＲＰ－ＨＰＬＣ法同时分离测定铜（Ⅱ）、铁（Ⅱ）、镍（Ⅱ）的方法，方法灵敏度高，对于铜、铁、镍的检测限分别为１μｇ／Ｌ， ２ μｇ／Ｌ和 ０．４ μｇ／Ｌ。用于实际样品测定，结果满意。     

反相HPLC测定钒,铌,钽的2—（2—吡啶偶氮）—5—二乙氨基苯酚配合物

以２－（２－吡啶偶氮０－５－二乙氨基苯酚（ＰＡＤＡＰ）为柱前衍生试剂，在含０．１％酒石酸的１０ｍｍｏｌ／Ｌ（ｐＨ３．５）ＨＡｃ－ＮａＡｃ缓冲溶液的甲醇／水（５０∶５０，Ｖ／Ｖ）中（５８０ｎｍ检测），在Ｃ１８柱上于１１ｍｉｎ内实现了Ｖ、Ｎｂ、Ｔａ的同时分离及测定，检出限（Ｓ／Ｎ＝３）杰０．３４、０．２９、７．３０ｎｇ／ｍＬ．该法灵敏度高，用于矿样分析所得民推荐值相行，标准加入回收率为９９．０％～１０     

高效液相色谱法测定血清中茶碱浓度

采用高效液相色谱,分析柱：３μｍ,３．３ｃｍ＊４．６ｍｍ,Ｉ．Ｄ（Ｐｅｒｋｉｎ Ｅｌｍｅｒ,ＵＳＡ）;预柱：１０μｍ,１ｃｍ＊２．１ｍｍ,Ｉ．Ｄ（Ｐｅｒｋｉｎ ＥＬｍｅｒ,ＵＳＡ）;以乙酰氨基酚为内标对氯仿－异丙醇（９５：５,Ｖ／Ｖ）提取样品进行了分析,流动相：０．１ｍｏｌ／Ｌ醋酸缓冲液（ＰＨ＝４．５）－甲醇（７０：３０,Ｖ／Ｖ）;检测波长：２７０ｎｍ;流速０．５ｍＬ／ｍｉｎ,３ｍｉｎ即完成一次茶     

新型高效棒状高效液相色谱柱的制备与评价

制备了新型高效棒状（甲基丙烯酸－苯乙烯－二乙烯基苯）共聚物高效液相色谱柱,扫描电镜显示其具有大孔网络结构,从而表现出良好的通透性。以乙腈－水（９０／１０,Ｖ／Ｖ）为流动相,在流速为２．０ｍＬ／ｍｉｎ下,柱压仅为２．５ＭＰａ,采用等度淋洗实现了多环芳烃及芳香酸的分离。该方法简便且重现性好,具有很好的发展潜力。     

高效液相色谱法和因子分析—紫外光度法测定荧光增白剂中两种成分

本文采用两种同时测定荧光增白剂工业产品中，１，４－（２，４′－氰基苯乙烯基）苯（记为ＥＢ）和异构体１，４－双（２－氰基苯乙烯基）苯（记为ＥＲ）两组分的方法，一种是ＨＰＬＣ法，采用Ｓｈｉｍ－ｐａｃｋＣＬＣ－ＳＩＬ柱（５μｍ，６．０ｍｍｉ．ｄ×１５０ｍｍ）正己烷－乙酸乙酯（９０：１０Ｖ／Ｖ）为流动相，流速２ｍＬ／ｍｉｎ，柱温３０℃检测波长ＵＶ３６０ｎｍ方法简单，准确，快速，另一种是因子分析－紫外光度法     

反相高效液相色谱法分离铂族金属及其伴生元素

本文报道以２－（６－甲基－２－苯并噻唑偶氮）－５－二乙氨基酚作柱前衍生试剂，以甲醇／水＝８２／１８（Ｖ／Ｖ），含１０ｍｍｏｌ／ＬｐＨ５．０醋酸盐缓冲溶液，１０ｍｍｏｌ／Ｌ水杨酸钠，５ｍｍｏｌ／ＬＴＢＡ．Ｂｒ作流动相，反相高效液相色谱法定量分离测定Ｒｕ（Ⅲ），Ｒｈ（Ⅲ）、Ｐｄ（Ⅱ）、Ｏｓ（Ⅳ）、Ｉｒ（Ⅳ）、Ｐｔ（Ⅱ）、Ｃｏ（Ⅱ）、Ｎｉ（Ⅱ）和Ｃｕ（Ⅱ）。当Ｓ／Ｎ＝３时，各金属离子的检出限分别为（ｎｍ     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Copper catalyzed/mediated synthetic methodology for ebselen and related isoselenazolones

Scope of the copper catalyzed/mediated selenium-nitrogen coupling reaction has been studied for the synthesis of isoselenazolones. It is noticed that the 2-chloro, 2-bromo-, and 2-iodo-aryl amides substrates can be exploited in the selenium-nitrogen coupling reaction by employing 25-100 mol % of CuI/1,10-phenanthroline (L) and potassium carbonate as a base in DMF. Furthermore, electron rich 2-chloro-arylamides also underwent selenium-nitrogen coupling reaction to give biologically important selenium-nitrogen heterocycles. Also, copper-catalyzed selenium-nitrogen coupling reaction has been meticulously applied for the synthesis of diaryl diselenides having methoxy, amine, and amide functionality from respective aryl iodides in the presence of stoichiometric amount of succinimide as an external Se-N coupling partner.     

Knoevenagel condensation catalyzed by novel Nmm-based ionic liquids in water

A series of novel N-methyl morpholine (Nmm) based ionic liquids with 1,2-propanediol group were synthesized and used as catalysts for Knoevenagel condensation at room temperature in water. Under the effect of the catalyst, various aldehydes or aliphatic ketones could react with a wide range of activated methylene compounds well, including malononitrile, alkyl cyanoacetate, cyanoacetamide, β-diketone, barbituric acid, 2-arylacetonitrile and thiazolidinedione. Furthermore, most of the products could be separated just by filtrating and washing with water. Additionally, the catalyst is recyclable and applicable for the large-scale synthesis.     

Construction of polyheterocyclic spirotetrahydrothiophene derivatives via sulfa-Michael/aldol cascade reaction

A series of polyheterocyclic spirotetrahydrothiophene derivatives were obtained in moderate to excellent yields via a catalyst-free sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 under mild conditions. We also present the first asymmetric sulfa-Michael/aldol cascade reaction of chalcones 1 and commercially available 1,4-dithiane-2,5-diol 2 with moderate to good enantioselectivities catalyzed by readily available chiral phase-transfer catalysts (PTCs).     

Suzuki-Miyaura reactions of the soluble guanylate cyclase inhibitor NS2028: a non-product specific route to C-8 substituted analogues

Both soluble guanylate cyclase (sGC) inhibitors ODQ 1 and NS2028 2 are synthesized via improved protocols. In the former case treating 3,4-dihydroquinoxalin-2(1H)-one oxime 8, which can be prepared in two steps from 1,2-benzenediamine, with 1,1′-carbonyldiimidazole (CDI) gives the dihydro-ODQ 10 that in the presence of KMnO₄ oxidises to give ODQ 1 in an overall yield of 46% starting from 1,2-benzenediamine. In the latter case, the synthesis affords NS2028 2 from 2-amino-4-bromophenol 3 in three steps with an overall yield of 85% and avoids the need for chromatography. Furthermore, Suzuki-Miyaura reaction conditions are described that enable the preparation of 8-aryl and 8-heteroaryl derivatives of NS2028 directly from NS2028 2. Finally, demethylation of the 8-(methoxyphenyl) substituted analogues afforded the 8-(hydroxyphenyl) derivatives 40-42. All new products are fully characterised.