尼泊金乙酯分子印迹固相萃取小柱的研制及应用

研制了一种对尼泊金乙酯具有特异性识别性能的分子印迹固相萃取小柱。用本体聚合法制备尼泊金乙酯分子印迹聚合物,通过静态平衡吸附实验及固相萃取实验表征其固相萃取性能,并结合UV法对滴眼液中的尼泊金乙酯进行测定。结果显示,尼泊金乙酯模板聚合物的吸附能力强于空白聚合物;印迹固相萃取柱对尼泊金乙酯标准溶液(0.04mmol/L)一...     

罗丹明B分子印迹聚合物微球的合成及其在固相萃取中的应用

以罗丹明B为模板分子,丙烯酰胺为功能单体,乙二醇二甲基丙烯酸酯为交联剂,采用沉淀聚合法制备了罗丹明B分子印迹聚合物(MIP)微球,并用扫描电子显微镜表征。 采用紫外分光光度法测定了印迹分子罗丹明B与功能单体丙烯酰胺二者之间的结合常数(K=5.303×103 (mol/L)-1)和化学计量比(n=1)。 考察了沉淀剂的种类和用量对聚合物微球的影响。 将分子印迹聚合物微球应用于固相萃取材料自制固相萃取柱,从加标罗丹明B的红椒粉中萃取罗丹明B。 本文优化了固相萃取条件,高效液相色谱检测表明,在一定的萃取条件下,分子印迹聚合物对加标量为0.479 mg/kg的辣椒中罗丹明B的萃取加标回收率可达91.7％～103.5%。     

非那西汀印迹聚合物固相萃取性能研究

研究非那西汀分子印迹聚合物的固相萃取性能。用本体聚合法制备非那西汀分子印迹聚合物,通过静态平衡吸附试验及固相萃取试验,研究其固相萃取性能。非那西汀模板聚合物的吸附能力明显强于空白聚合物。模板聚合物对浓度为0.03mmol/L的非那西汀标准溶液一次性萃取率为74.2%。非那西汀印迹聚合物对非那西汀具有特异性识别性能,可作为固相萃取固定相的应用研究。     

亲水性邻苯二甲酸二丁酯分子印迹聚合物的研制及应用

采用溶胶-凝胶技术,制备了邻苯二甲酸二丁酯(DBP)亲水性分子印迹聚合物(HYM IP)。静态吸附和选择性吸附实验表明,聚合物对DBP具有较高的吸附量与良好的特异吸附性。将其作为固相萃取填料,对水相样品中DBP的净化和富集效果优于C18柱。建立了亲水性分子印迹固相萃取结合高效液相色谱法检测化妆水中DBP的方法,检出限为4.46μg/kg,加标回收率在97.8%~98.7%之间,RSD小于2.4%。     

染料木素分子印迹聚合物的制备及其识别性能

以染料木素为模板分子、4-乙烯基吡啶(4-VP)为功能单体、乙二醇二甲基双丙烯酸酯(EGDMA)为交联剂、四氢呋喃(THF)为溶剂,采用本体聚合法制备了染料木素的分子印迹聚合物;采用静态平衡结合实验研究了该分子印迹聚合物对染料木素的结合能力和选择性能.结果表明,与化学组成相同的相应非印迹聚合物相比,染料木素分子印迹聚合物对染料木素的吸附性能和选择性更好.利用所合成的分子印迹聚合物作为固相萃取材料填充固相萃取小柱,可以选择性地从豆奶粉中分离、富集染料木素;此外,该分子印迹聚合物还有望用于其他豆制品的分析检验.     

分子印迹固相萃取技术检测江水、尿液及牛奶中雌激素残留

以β-雌二醇和炔雌醇的分子印迹聚合物为填料制备固相萃取小柱,选择60%(V/V)甲醇-水溶液作为雌激素的淋洗液,甲醇-乙酸(9:1,V/V)为洗脱液,洗脱两次可彻底洗脱固相萃取小柱中目标分子.以建立的萃取条件对上海黄浦江水、尿液、牛奶中雌激素进行富集,结合高效液相色谱法,建立了基于分子印迹固相萃取技术检测上述实际样品中...     

三聚氰胺分子印迹聚合物的制备及奶制品中三聚氰胺的分离

采用分子印迹技术,以三聚氰胺为模板分子,甲基丙烯酸为功能单体,乙二醇二甲基丙烯酸酯为交联剂,合成了对三聚氰胺具有较好选择性的分子印迹聚合物.通过静态平衡结合实验研究了该聚合物的结合能力和选择性能,与化学组成相同的相应非印迹聚合物相比,三聚氰胺的分子印迹聚合物对三聚氰胺有较高的吸附性能和选择性.以该分子印迹聚合物为固相萃取材料填充固相萃取小柱,可以从奶粉、纯牛奶等奶制品中选择性地分离、富集三聚氰胺,并有效地去除奶制品中的复杂基质,取得了良好的效果.对奶粉和液态奶提取液的加标回收率分别为91% ～103%、93% ～98%,相对标准偏差(n=3)分别为7.9%和1.1%.该分子印迹聚合物还有望用于其它奶制品的分析.     

分子印迹-固相萃取-高效液相色谱法测定鱼肉中的孔雀石绿

以本体聚合法制备孔雀石绿(MG)分子印迹聚合物,并以此为填料,制作针对孔雀石绿的分子印迹固相萃取小柱。鱼肉样品经乙腈超声提取,提取液过分子印迹固相萃取小柱,用甲醇-乙酸(9+1)混合液洗脱,洗脱液采用Eclipse Plus C18色谱柱分离,以50mmol·L-1乙酸盐缓冲溶液-乙腈(4+6)混合液为流动相进行洗脱,检测波长为620nm。孔雀石绿的线性范围为1.00~50.0μg·L-1,检出限(3S/N)为0.62μg·kg-1。对空白鱼肉样品进行加标回收试验,回收率在86.6%~95.4%之间,测定值的相对标准偏差(n=5)在3.6%~6.8%之间。     

槲皮素表面分子印迹聚合物的制备及其应用研究

以接枝双键的凹凸棒土(TM)为载体,槲皮素为模板分子,采用表面印迹技术制备对槲皮素具有特异吸附性能的分子印迹聚合物(MIP)。利用光谱法选择实验条件及对化合物表征。采用静态法研究聚合物对槲皮素的结合性能与识别性能。结果表明,该分子印迹材料对槲皮素具有特异的识别特性和优良的亲和性,提高了传统聚合物的结合率。以该印迹聚合物为固相萃取材料,结合高效液相色谱法,对白菜中的槲皮素进行分离富集,方法回收率为84.0%~90.6%,相对标准偏差低于5.6%。     

亲水性分子印迹聚合物的制备及其在天麻素分析检测中的应用

以天麻素为模板分子,α-1-烯丙基-2-N-乙酰胺基葡萄糖为新型亲水性功能单体,N,N'-亚甲基双丙烯酰胺为交联剂,合成了对天麻素有高选择性的亲水性分子印迹聚合物(MIPs)。吸附结果表明,MIPs能够特异性识别天麻素。对MIPs吸附剂性能的考察证明,亲水性天麻素MIPs可作为固相萃取(SPE)吸附剂分离纯化天麻素。方法验证实验显示了良好的回收率(90.4%~97.1%)和精密度(3.3%~5.2%,n=5)。该文以新型亲水性功能单体为基础,建立了天麻素的分子印迹固相萃取样品前处理方法。     

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.     

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.     

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.     

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.     

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.