高效液相色谱法测定腐竹中的三聚氰胺

建立了腐竹中三聚氰胺的高效液相色谱检测方法.样品经0.1 mol/L的盐酸溶液提取,亚铁氰化钾和乙酸锌沉淀蛋白,以0.05 mol/L磷酸二氢钾溶液(pH 3.0)-乙腈为流动相,300-SCX离子交换色谱柱分离,二极管阵列检测器于波长240 nm处进行检测.该方法线性范围为0.1～5 μg/mL,检出限为2.0 mg/kg,测定结果的RSD为1.3%～2.5%(n=6),加标回收率为85.8%～92.1%,方法能够满足检测要求.     

环境水样中己烯雌酚与双烯雌酚的离子液体分散液-液微萃取/高效液相色谱法测定

以离子液体([Omim][PF6])为萃取剂,采用冷诱导分散液-液微萃取对环境水样中的己烯雌酚和双烯雌酚残留进行富集.优化后的萃取条件:在pH 3.0的条件下,以50 μL离子液体为萃取剂,0.8 mL甲醇为分散剂,采用反相 Extend-C18柱(5 μm, 250 mm×4.6 mm),流动相为水-甲醇(体积比40 ∶ 60),流速:1.0 mL/min,柱温:35 ℃,检测波长:245 nm.在优化的萃取条件下,己烯雌酚和双烯雌酚的线性范围均为2.5 ～200 μg/L,检出限(S/N=3)为80 ng/L.应用于环境水样中己烯雌酚和双烯雌酚的检测,加标回收率为93% ～98%,相对标准偏差为3.0% ～5.4%,建立的方法简单、环保.     

用于测定空气中甲醛的电子鼻

制作了可定量检测空气中甲醛的便携式电子鼻.该电子鼻由传感器阵列、信号调理电路、模式识别系统以及显示系统等4个部分组成,其中传感器阵列为4个半导体金属氧化物传感器.模式识别系统采用模糊神经网络算法.便携式甲醛电子鼻对甲醛气体响应专一,抗干扰能力强,且定量结果精确,可用于甲醛气体的现场检测.对于0.001～0.25mg/L浓度范围内的甲醛气体,电子鼻定量测报的正确率达到81.3%;对于干扰气体存在下的甲醛气体,未出现错误测报.     

新型微梁阵列生化传感器的研制

为了消除单微梁生化传感系统中存在的温度漂移、溶液折射率变化等环境噪声影响,同时实现多种靶标分子的快速并行检测,设计制作了新型微梁阵列生化传感器.利用压电驱动激光束扫描微梁阵列,并通过光杠杆法实时读出微梁弯曲信号,即可得到在微梁表面发生的特异性生化反应的动力学曲线.对250 μm间距的两定点的9h扫描实验数据验证了系统光路的稳定性;同时进行了温度激励测试,升温6℃后微梁阵列弯曲信号基本保持一致(误差6.5％),验证了系统检测的可靠性.最后,利用自制毛细管阵列套合修饰装置,成功将克伦特罗抗体修饰到微梁阵列一侧的金表面上,对待测液中10μg/L克伦特罗标样进行了准确检测,验证了此传感系统在生化检测中的实际可行性.     

清开灵注射液中黄芩苷含量的微乳液相色谱法测定

建立了微乳液相色谱(MELC)测定中药复方制剂清开灵注射液中黄芩苷含量的分析方法,并考察了微乳流动相的组成及pH值等影响因素.最佳条件为:采用Hypersil BDS C18 5 μm(4.6 mm×150 mm)色谱柱,柱温30 ℃,以3%十六烷基三甲基溴化铵-0.8%乙酸乙酯-7%乙腈-0.01 mol/L 四丁基溴化铵(磷酸调pH至3.0)为流动相,检测波长276 nm.对照品和样品均用70%甲醇处理.结果表明,黄芩苷的线性范围为25 ～100 mg/L,相关系数r=0.999 9.精密度实验和稳定性实验的RSD分别为1.0%(n=6)和0.50%(n=5),平均加标回收率和RSD值(n=6)分别为99%、1.9%.市售9批样品中黄芩苷的质量浓度为4.05 ～5.05 g/L,符合药典规定.     

红景天中红景天甙和酪醇的毛细管电泳法分析

利用毛细管电泳法分离测定两种红景天中红景天甙和酪醇的含量,所用毛细管规格为48.5cm×50μm,二极管阵列紫外检测器(DAD)检测波长221nm,最佳分离条件:电压21kV,分离温度25℃,背景电解质为含有30mmol/L十二烷基硫酸钠(SDS),2.5+97.5(V/V)乙腈的14mmol/L硼酸溶液,pH10.7。红景天甙与酪醇分别在60.0～7.5μg/mL和27.5～3.5μg/mL质量浓度范围内与电泳峰面积呈现良好线性关系,检测下限分别为3.0和1.5μg/mL。对标准品进行6次测定,迁移时间的RSD为0 25%和0 39%,峰面积的RSD为5 26%和3 52%。     

用多克隆抗体构建的夹心免疫传感器检测心肌肌钙蛋白I

用表面等离子体子共振生物传感器构建对心肌肌钙蛋白I特异性的免疫传感器检测心肌肌钙蛋白I,并建立两种检测方法:直接法的最低检测限为2.5μg/L,基于传感膜上的夹心免疫法的灵敏度为0.5μg/L,检测范围为0.5～20μg/L,批内及批间精密度分别为3.5%～4.9%,6.1%～7.4%;用夹心法及国外试剂盒对40名健康献血者和20例急性心肌梗死患者血清心肌肌钙蛋白I水平进行检测,两者符合率为95%.     

固相微萃取-气相色谱法测定水中有机磷农药

提出了固相微萃取样品-气相色谱法测定水中6种有机磷农药残留量的方法。为使固相微萃取达到更高的效率,选择65μm的聚二甲基硅氧烷/二乙烯苯（PDMS/DVB）萃取头,萃取温度及时间为80℃和20 min,在10 mL试样中加入氯化钠1.5 g作为盐析剂。用HP-5毛细管色谱柱分离,电子捕获检测器检测。6种有机磷农药的质量浓度均在1.0～50.0μg·L^-1范围内与其峰面积呈线性关系,方法的检出限（3S/N）在0.026～0.064μg·L^-1之间。方法用于水样分析,测定值的相对标准偏差（n=6）在3.0～5.6%之间,加标回收率在86.2%～115.7%之间。     

光纤分导微梁阵列生化传感装置研制及检测应用

研制了一套基于光杠杆原理的微悬臂梁阵列传感器平台,并通过使用设计制作的微悬臂梁阵列芯片展示其在生物化学方面的检测应用.传感器平台使用光导纤维束分别与激光器耦合作为悬臂梁阵列的扫描光源,具有良好的检测稳定性,检测信号噪声水平约为2 nm;设计制作的微悬臂梁阵列芯片具有良好的平直度,温度响应均匀一致,各梁温度改变响应灵敏度偏差不超过5.0％.将整套传感系统被用于检测水溶液中的Hg2+,检测浓度范围为1 ～ 200 ng/mL;同一浓度下微悬臂梁阵列检测结果曲线一致性良好,平均偏差小于15％.在研制仪器平台上,分别实现了自制和国外商品化芯片对1.0和0.2 ng/mL样品的检测,结果表明,制作的微悬臂梁阵列芯片的检测灵敏度相对较低,需进一步改进悬臂梁阵列制作工艺.     

微流控芯片流动注射气体扩散分离光度测定系统的研究

提出了纳升级进样量的微流控芯片流动注射气体扩散分离光度检测系统. 制作三层结构微流控芯片, 在玻璃片上加工微反应通道, 用聚二甲基硅氧烷[Poly(dimethylsiloxane), PDMS]加工气体渗透膜和具有接收气体微通道的底片, 实现了生成气体的化学反应、气-液分离和检测在同一微芯片上的集成化. 采用缝管阵列纳升流动注射进样系统连续进样, 用吸光度法测定NH+4以验证系统性能. 结果表明， 该系统对NH+4的检出限为140 μmol/L(3σ), 峰高精度为3.7%(n=9). 在进样时间12 s、注入载流48 s和每次进样消耗200 nL试样条件下, 系统分析通量可达60样/h. 若加大样品量到800 nL, 使接收溶液停流1 min, 该系统对NH+4的检出限可达到35 μmol/L(3σ), 但分析通量降低到20样/h.     

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.