苯丙共聚物-聚硅氧烷复合固相微萃取涂层的制备及性能研究

合成了苯乙烯-丙烯酸乙酯共聚物,以此聚合物与甲基聚硅氧烷色谱固定液混合作为固相微萃取头涂层。通过热分析手段考察了该涂层的热稳定性,涂层使用温度可达280℃。使用微量进样器和不锈钢毛细管,自制了SPME装置。使用该涂层萃取分析了水中氯苯系化合物,各标准样品质量浓度在0—20μg／L内与色谱峰面积呈良好线性关系（r=0．9674—0．9934）,检出限为0．28—0．64ng／L,相对标准偏差为5．4％-7．7％,加标回收率为91％-99％。将自制涂层与商品涂层（PDMS、PA）进行了比较,结果表明苯丙聚合物-甲基聚硅氧烷复合涂层对氯苯系化合物具有优良的吸附特性。在固相微萃取研究和应用中,提供了新的吸附物质和色谱固定液与石英纤维结合的新途径。     

吐温80-盐-水体系的液-固萃取光度法测定痕量钴

研究了Ｃｏ（Ⅱ）－ＰＡＲ在吐温８０－硫酸铵体系中的最佳萃取条件,建立了生物样品中测定痕量钴的非有机溶剂液－固萃取光度法。在ｐＨ７．０～１０．５的ＮＨ３．Ｈ２Ｏ－ＮＨ４Ｃｌ缓冲溶液中,１金属配合物Ｃｏ（Ⅱ）－ＰＡＲ可被吐温８０固相富集,最大吸收波长为５１５ｎｍ,钴含量在０～５．０ｕｇ／ｍＬ范围内服从比尔定律,可用于头发、茶叶和维生素Ｂ１２针剂中痕量钴的测定。     

固相微萃取—毛细管气相色谱法快速分析水中氯苯类化合物

固相微萃取是一种快速，简便，集萃取浓缩进样于一体的样品前处理技术，具有分析时间短，灵敏度高，无需有机溶剂的优点。方法用固相微萃取富集水中氯苯类化合物，毛细管气相色谱分离分析，整个分析过程只需２０ｍｉｎ，检出限可达０．１－２μｇ．ｌ＾－１，已用于地面水水源中氯苯类化合物含量的测定。     

苯-丙-硅共聚物固相微萃取涂层制备及性能研究

合成了苯乙烯-丙烯酸丁酯-乙烯基三乙氧基硅氧烷三元共聚物,并对其结构进行了表征,对其热稳定性、粘度、与纤维的结合能力等物理性能进行了测试。使用自制固相微萃取装置,研究了该聚合物作为固相微萃取涂层的应用性能,对水中小分子烷基苯、氯苯、硝基苯进行了萃取实验,将萃取结果与商品涂层萃取结果进行了比较,令人满意。实验数据表明,苯-丙-硅三元共聚物作为固相微萃取涂层性能优良。     

硅氧烷-聚氨酯共聚物的制备及其作为固相微萃取头涂层用于分离水中芳香族化合物

合成了硅氧烷-聚氨酯共聚物,并采用红外光谱、扫描电子显微镜和能谱仪对该共聚物进行了表征。将其用于固相微萃取用石英纤维的表面涂层并制备了萃取头。将此固相微萃取装置的萃取头萃取和分离顶空样瓶水样中的芳香化合物并引入仪器进行色谱分析。结果表明:用共聚物涂层的石英纤维制成的萃取头的最高使用温度为260℃,涂层表面硅元素分布均匀。苯、氯苯、硝基苯的质量浓度均在50.0μg·L~(-1)范围以内与其色谱峰峰高呈线性关系,方法的检出限(3S/N)依次为0.432,0.756,0.511μg·L~(-1)。     

聚丙烯酸树脂涂层HS-SPME-GC-MS监测城市污水中的芳香烃化合物

采用聚丙烯酸树脂涂层-固相微萃取-气相色谱-质谱(PA—SPME—GC—MS)联用技术,在优化的萃取条件下检测了城市污水中的苯系物和多环芳烃等芳香烃化合物．该方法的最低检出限达12ng／L水平,相对标准偏差为1．7％～9．8％．     

固相微萃取-气相色谱/质谱联用分析室内空气中的苯系物

自制了一种固相微萃取采样装置,建立了固相微萃取-气相色谱/质谱(SPME-GC/MS)联用测定室内空气中苯系物的分析方法。方法的线性范围为1~300μg/m3,检出限为0.1~0.3μg/m3,RSD(n=6)3.2%~15%。采用该方法研究了广州市内20户新装修民居中苯、甲苯、乙苯、对二甲苯和1,3,5-三甲苯的含量及分布,并探讨了苯系物的来源。     

人低密度脂蛋白~125Ⅰ固相标记──Iodogen法

本文报道了利用固相氧化剂１，３，４，６，—四氯—３ａ，６ａ，－二苯基甘脲（Ｉｏｄｏｇｅｎ）对人血清低密度脂蛋（ＬＤＬ）进行１２５Ⅰ标记的方法，结果表明：１２５Ｉ－ＬＤＬ的比放射性为１８５～５１８ｃｐｍ／ｎｇＬＤＬ，游离１２５Ⅰ含量在０．２７～１．７５％之间，脂质标记率＜１％，１２５Ｉ－ＬＤＬ浓度２５０～７５０μｇ／ｍｌ，１２５Ｉ－ＬＤＬ的生物活性经受体实验证实与天然脂蛋白一致．符合脂蛋白代谢研究的要求．本法具有反应条件温和，不易损伤脂蛋白，脂质标记率低．固相标记，不需要复杂设备等优点，为进行脂蛋白受体的研究提供了可靠的方法．     

固相萃取结合毛细管气相色谱法分析血浆中5种氨基甲酸酯

报道了用Ｘ－５树脂固相萃取分离纯化、气相色谱法（ＧＣ）定性和定量同时测定血浆中５种氨基甲酸酯杀虫剂的方法。含药物的血浆可直接用萃取柱处理,用甲醇－乙酸乙酯作为洗脱剂。不同药物的回收率在８０．０％～９２．５％之间,最低检测浓度为１ｍｇ／Ｌ,检测灵敏度及线性范围（０～４０ｍｇ／Ｌ）适合临床中毒急救分析的需要。     

固相微萃取-毛细管气相色谱法测定污染棕榈油中的低浓度二甲苯

采用一种新型的样品制备技术－固相微萃取代替传统的顶空进样技术,结合毛细管气相色谱,快速,灵敏地检测出污染进口棕榈油的低浓度的二甲苯。以苯为内标,以大豆油模拟基质制作标准曲线。在０．２￣２０ｍｇ／ｋｇ浓度范围内呈线性,对样品和标样萃取的精度良好。     

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%.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

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.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

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.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.