YL－110型流动注射测金装置的研制

研制了一台流动注射测金装置。该装置由一台四道蠕动泵、两支旋转阀，一支８５３１纤维分离富集柱和有关电路组成一个整体，靠蠕动泵自动输送试样溶液，酸洗液和金洗脱液，使金在Φ３×４０ｍｍ的微型纤维柱上富集，由控制电路控制旋转阀切换自动完成柱平衡，进样，洗涤，洗脱过程，金洗脱液自动送入原子吸收分光光度计测定金。８５３１纤维是金的良好吸附剂，具有选择性容量大的优点。试样经王水分解后可直接进样测定。该装置与原子吸收分光光度计联用测定金。金的特征浓度可达０．６ｎｇ／ｍＬ每小时可测定４０～６０次。用本装置分析０．１６μｇ／ｍＬ金溶液，ＲＳＤ为０．８％。用于分析化探样品，铜精矿，电解铜等试样中金，得到满意的结果。     

YL—110型流动注射测金装置的研制

研制了一台流动注射测金装置。该装置由一台四道蠕动泵，两支转阀，一支８５３１纤维分离富集柱和有关电路组成一个整体，靠蠕动泵自动输送试样溶液，酸洗液和金洗脱液，使金在Ф×４０ｍｍ的微型纤维柱上富集，由控制电路控制旋转阀切换切换自动完成柱平衡，进样，洗，脱过程，金洗脱液自动送入原子上分光光度计测定金。８５３１纤维是金的良好吸附剂，具有选择性容量大的优点。试样经王水分解后可直接进样测定。该装置与原子吸收分     

Cyanex272负载树脂分离-ICP-MS法测定高纯氧化钕中痕量稀土杂质

采用萃取色谱法,以Cyanex272负载树脂为固定相制成微型分离柱,以HCl为淋洗液,研究了Nd2O3基体的分离条件,分离周期为35min。建立了分离Nd后测定Tb、Dy、Ho以及内标补偿法直接测定其它稀土杂质的高纯Nd2O3中14个稀土杂质的ICP MS分析方法。方法检出限为0.03～0.30μg g,加标回收率为91.0%～110.0%,相对标准偏差为2.0%～4.9%。方法可满足快速测定99 999%Nd2O3中14个稀土杂质的要求。     

微柱分离-ICP-MS测定高纯氧化钆中14种稀土杂质

研究了采用自制微柱分离装置分离Gd2O3基体的条件。99．9％以上基体被分离，分离周期为36min。建立了高纯Gd2O3中分离Gd后测定Yb、Lu以及内标补偿法直接测定其它12种稀土杂质的ICP—MS分析方法.定量下限为0．08～0．80μg／g，加标回收率为85％～115％，相对标准偏差为1．1％～8．5％、方法可满足快速测定99．999％ Gd2O3中14种稀土杂质的要求。     

微型柱分离-ICP-MS法测定高纯氧化铽中14个稀土杂质元素

研究了微型柱分离 电感耦合等离子质谱法(ICP MS)测定高纯Tb4O7中痕量Lu的方法,采用Cyanex272负载树脂微型分离柱,选定了分离大量Tb4O7基体的实验条件,分离周期为40min。建立了微型柱分离Tb后测定Lu以及内标补偿法直接测定其它稀土杂质的高纯Tb4O7中14个稀土杂质元素的ICP MS分析方法。方法检出限为0.003～0.10μg g,加标回收率为86.6%～114%,相对标准偏差为1.1%～18%。方法可满足快速测定99.999%Tb4O7中14个稀土杂质元素的要求。     

流动注射微柱预富集等离子体原子发射光谱法测定高纯锌中痕量稀土元素

本文报道以DCS-偶氮胂固定于活性炭上作为固定相,用于流动注射微柱预富集体系和等离子体原子发射光谱测定痕量稀土元素.测定了吸附材料对稀土元素的静态和动态吸附容量,分别达几十和几个mg/g吸附材料;对影响柱预富集的PH、上柱速度、洗脱酸度、柱尺寸等因素进行了详细考察;在优化条件下,富集倍数为10倍左右.对La、Nd、Eu、Gd、Tb、Dy、Ho和 Lu等元素的检出限为 μg/L级,RSD在 1.5％～3.9％之间(n=6,单一稀土浓度0.085 mg/L).该法应用于高纯锌中痕量稀土元素的测定,试样加入回收率在 84.5％～97.6％之间,分析结果满意.     

应用液-液色谱联用技术在线富集测定环境水中西维因和抗蚜威的残留量

为高效液相色谱法测定环境水样中残留的西维因和抗蚜威的含量,应用了液-液色谱联用技术,实现了在线富集、分离和检测。分析中用YWG-C18（10mm×4．6mm,10μm）和YWG-C18（150mm×4．6mm,10μm）依次作为富集柱和分离柱,以体积比45比55混合的甲醇与水的混合溶液作为流动相,其流速为1．0mL·min^-1。选定紫外光度检测的波长为228nm,试样溶液在富集柱上的流速为5．0mL·min^-1。此外,对渗漏体积等参素也作了试验,分析信号值与两农药的质量浓度在0．04～1．0μg·L^-1范围内呈线性关系。测得方法的检出限（S／N=3）为0．008μg·L^-1（西维因）和0．014μg·L^-1（抗蚜威）,回收试验的结果在93％～119％之间。还对日内和日间精密度进行了试验,测定西维因的日内精密度为1．3％～20．0％,日间精密度为2．39／6～22．2％,测定抗蚜威的日内精密度为2．0％～10．8％,日间精密度为2．2％～5．8％。     

希土元素与苯甲酰三氟丙酮的螯合物

用三种方法制备了两类希土和苯甲酰三氟丙酮的固体螯合物Ln(BTA)_4·Hpip(Ln=La,Pr,Nd,Sm,Eu,Gd,Tb,Dy,Er及Y)和Ln(BTA)_3·2H_2O(Ln=Nd,Eu及Tb).测定了Nd(BTA)_4·Hpip的分子量和Ln(BTA)_4·Hpip的熔点.研究了Nd(BTA)_4·Hpip,Sm(BTA)_4·Hpip和Nd(BTA)_3·2H_2O的热稳定性,并与相应的苯酰丙酮螯合物进行了比较.     

无降解离子色谱法对食品中甲醛次硫酸氢钠残留的测定

首次报道了用水直接提取,离子色谱分离、测定食品中甲醛次硫酸氢钠的方法。采用IonPac ASl8作为分离柱,比较了NaHCO3-Na2CO3、Na2B4O7和KOH溶液的淋洗效果,发现KOH淋洗液效果最佳。实验研究了甲醛次硫酸氢钠的热稳定性及食品中常见阴离子与甲醛次硫酸氢钠的分离度。在选定的离子色谱测定条件下,甲醛次硫酸氢钠在0．1～200mg／kg的范围内有较好的线性。方法的加标回收率、相对标准偏差、检出限分别为88％～101％、3．3％～5．0％、0．05mg／kg。方法应用于年糕样品中残留甲醛次硫酸氢钠的检测,获得了满意的结果。     

异烷基膦酸1-甲庚基酯负载树脂分离原子吸收光谱法测定氧化钇中痕量铕铽铒和镱

异烷基膦酸1-甲庚基酯(代号5712)是在较低酸度下具有优良稀土分离性能的萃取剂。本文测定了15种稀土(Ⅲ)在5712-负载树脂与不同浓度的HNO_3之间的分配比。研究了5712-负载树脂柱分离Y、Tb、Dy、Ho、Er的最优条件。0.58mol/L HNO_3可使这5种元素分离良好。利用5712-负载树脂分离和富集高纯氧化钇中痕量Eu、Tb、Er和Yb,然后再以原子吸收光谱法测定。经过本法分离和富集,除去了大量基体,从而提高了测定的灵敏度。     

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.