顶空衍生固相微萃取-气相色谱质谱法测定聚碳酸酯树脂中的环境雌激素

建立了固相微萃取-气相色谱质谱联用测定聚碳酸酯树脂中环境雌激素4-枯基苯酚和双酚A的分析方法。优化了固相微萃取纤维、萃取温度和时间、解吸时间、搅拌速度、pH等萃取条件及衍生化温度和时间、衍生化方式等衍生化条件，并对样品浸泡时间、浸泡温度等进行了研究。方法的线性范围为0．05μg/L～1mg／L，4-枯基苯酚和双酚A的检出限分别为50ng／L和0．5ng／L，相对标准偏差（RSD，n=5）分别为5．2％和1．6％，平均回收率（n=3）在90．50％～107．3％之间，该方法简单、快速、灵敏。     

固相微萃取-气相色谱-质谱联用分析水中的痕量扑草净

研究了固相微萃取－气相色谱－质谱联用测定水中扑草净的方法，采用聚丙烯酸酯（PA）萃取头，对影响固相微萃取萃取效率的萃取时间、搅拌速度、pH值以及盐度等进行了优化。在优化实验条件下，方法线性范围在0．1mg/mL-1000ng/mL之间，检出限为1．5ng/L。用该法分析了合成井水、自来水和湖水样品，回收率在85．4％－89．1％之间，相对标准偏差在1．8％－5．2％之间。本方法适合于水中痕量扑草净的分析。     

顶空固相微萃取-气相色谱-质谱测定水中异味化合物

采用顶空固相微萃取-气相色盐／质谱联用测定了水中常见的3种异味化合物，即2-甲基异茨醇、土腥素和β-柠檬醛。研究并讨论了纤维头的类型、盐的种类和浓度、温度、萃取时间、搅拌和解吸时间等因素对异味化合物萃取量的影响。结果表明：在水样中加入30％（W／V）的NaCl溶液，采用65μm PDMS／DVB纤维头，在搅拌的条件下，于60℃顶空萃取40min为异味化合物固相微萃取的最佳条件。在优化的条件下，使异味化合物吸附于纤维涂层后，将其在250℃高温下解吸，再用GC—MS分析。土腥素、β-柠檬醛、2-甲基异茨醇的检出限依次为1．0、1．3和1．7ng／L；其相对标准偏差分别为4．9％、8．4％和6．2％：3种异味化合物在5～1000ng／L的范围内线性关系良好，相关系数均大于0．997。因此，用该方法分析水中痕量（ng／L级）的异味化合物，结果满意。     

顶空固相微萃取-气相色谱法测定环保水性涂料中的挥发性有机物

建立了一种固相微萃取．气相色谱同时测定环保水性涂料中的苯系物和卤代烃的方法。选择涂层厚度为70μm的聚乙二醇-二乙烯苯(CW-DVB)萃取纤维,对固相微萃取的萃取条件进行了优化。该法相对标准偏差小于10％,样品的加标回收率大于72．2％,已成功地测定了11种水性涂料中的苯系物和卤代烷。     

固相萃取-气相色谱法测定地下水中痕量酞酸酯的研究

本文建立了固相萃取-气相色谱法定量分析地下水中酞酸酯类（PAEs）有机污染物的方法。利用正交试验和单因素实验对影响回收率的4个主要因素（洗脱溶剂种类、水样体积、洗脱溶剂体积、固相萃取小柱填料量）进行了萃取条件的优化。综合考虑各方面因素后确定的最佳萃取条件为：二氯甲烷和丙酮为洗脱剂,体积8mL、0．5L水样、柱填料500mg。方法线性范围0．05～10．00μg／L,检出限0．05～0．341ng／L,相对标准偏差0．038％～1．107％。该方法应用于江汉平原地下水中PAEs测定,取得满意结果。     

固相微萃取-脉冲火焰光度法测定大气及水中的路易氏剂

建立了固相微萃取（SPME）与气相色谱/脉冲火焰光度检测器（GC／PFPD）联用测定大气和水中路易氏剂及其水解产物的方法。探讨了影响SPME萃取效率的萃取头类型、萃取时间、解吸时间等因素。优化了PFPD的条件参数、衍生化试剂及衍生条件。在优化的条件下，路易氏剂衍生产物的响应值与浓度有良好的线性关系。本方法对水中路易氏剂及其水解产物的检出限为0．1μg/L；气体中路易氏剂的检出限为10ng／m^3；水样的加标回收率为96．7％-102．1％；气体样品的加标回收率为94．9％-103．0％；RSD为2．06％。     

固相萃取-气相色谱/质谱法同时测定涂料中的8种有机锡

建立了一种固相萃取（SPE）前处理、气相色谱-质谱（GC-MS）法同时测定涂料中8种有机锡的方法。样品采用阳离子交换固相萃取小柱净化,最佳固相萃取条件为：固相萃取小柱分别用5mL甲醇、7mL洗脱液（氯化铵、甲醇、冰乙酸的混合溶液）预洗,10mL甲醇活化;将用甲醇稀释的涂料样品上样后,用5mL甲醇淋洗,抽干2min,7mL乙酸-氯化铵甲醇溶液（10：90,V／V）洗脱溶液洗脱。洗脱液用四乙基硼化钠溶液衍生后,气相色谱-质谱法进行定性定量分析。结果表明：以标准加入法计算回收率,在1.68％-16.84%添加范围内,平均回收率在85％-105％之间,相对标准偏差均小于12％。     

石墨烯复合材料固相微萃取涂层的制备及其对水样中六六六残留的测定

该文制备了石墨烯复合材料并将其包覆于铜丝上作为萃取纤维,利用固相微萃取／气相色谱-电子捕获检测器(GC-ECD)技术,建立了环境水样中有机氯农药六六六残留的直接测定方法.优化了萃取时间、萃取温度、pH值及离子强度等固相微萃取条件在优化的实验条件下,所制备的纤维对α-六六六、β-六六六、γ-六六六与δ-六六六的加标回收率...     

多壁碳纳米管固相微萃取纤维制备及其在海水中多溴联苯测定中的应用

通过以Nation为黏合剂、不锈钢丝为涂层载体,制备了多壁碳纳米管固相微萃取纤维．该纤维的制备方法快速、简便、成本低,并具有热稳定性好（300℃）、使用寿命长（〉100次）、对多溴联苯萃取效率高等特点．研究优化了影响萃取及分离效率的解吸温度和时间、萃取时间、搅拌速度、盐度等实验条件,进行了海水中多溴联苯的测定．对一溴联苯的线性范围为0．1-5．0ng／mL,而二溴联苯、三溴联苯、四溴联苯和五溴联苯的线性范围均为0．01～5．0ng／mL．方法的检测限为0．1～0．8ng／L．在优化的条件下分别测定了0．1和1ng／mL多溴联苯的海水加标样品,回收率在91．1％～107.3％之间,相对标准偏差小于12％．该方法分析时间短、灵敏度高、操作简便,适用于水样中多溴联苯的痕量分析．     

固相微萃取/高效液相色谱联用分析水样中邻苯二甲酸酯

研究了固相微萃取（SPME）／高效液相色谱（HPLC）联用测定环境中痕量邻苯二甲酸酯的分析方法,比较了5种不同类型涂层对5种邻苯二甲酸酯的萃取效果,采用3因素3水平正交实验设计对SPME的条件如萃取时间,离子强度,解吸时间等进行了优化,SPME优化的条件为：65μm聚二甲基硅烷／乙烯苯（PDMS／DVB）涂层,室温,搅拌速率1100r／min,萃取时间30min,纯乙腈解吸,解吸时间2min。HPLC的条件：C18反相色谱柱,乙腈-水（体积比60：40）梯度淋洗,流速1mL／min,紫外检测波长228nm。方法 的线性范围为0．50～80．00μg／L,检出限为0．11～2．20μg／L,相对标准偏差（n=6）为2．5％～9．6％,用于自来水、凉开水和雨水等实际水样的分析,回收率为82％～128％。     

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.