氯丙嗪分子印迹化学发光微流控传感器芯片的研究

以氯丙嗪分子印迹聚合物为识别物质,以鲁米诺-K3Fe(CN)6化学发光体系,建立了一种新型的氯丙嗪化学发光微流控分子印迹传感器芯片的检测方法。利用二氧化碳激光在聚甲基丙烯酸甲酯材质上刻蚀出200μm宽,150μm深的微通道,8 mm长,1 mm宽,0.5 mm深的微检测池。微检测池中填充50μm粒径大小的热聚合得到的氯丙嗪分子印迹聚合物作为识别物质,在线富集氯丙嗪,富集的氯丙嗪可以增强鲁米诺和K3Fe(CN)6的化学发光强度,以化学发光强度定量氯丙嗪量。该传感器的响应值与0.02~0.4μg/mL氯丙嗪呈良好的线性关系,检出限为8 ng/mL(3σ)。该微流控传感器芯片已用于测定人尿液中的氯丙嗪。     

分子印迹聚合物-流动注射-化学发光法测定磺胺脒

以磺胺脒为目标分子,二乙烯三胺为功能单体,环氧树脂为交联剂,合成对磺胺脒具有专一性识别的分子印迹聚合物(MIP),再将其制备成化学发光传感器,采用流动注射-化学发光法测定磺胺脒。样品溶液经传感器吸附120s后,用水洗涤传感器30s,传感器上吸附的磺胺脒与0.6mol·L~(-1)盐酸-1×10~(-3) mol·L~(-1)高锰酸钾-8%(体积分数)甲醛混合溶液发生化学发光反应,反应时间为160s。磺胺脒的浓度在5×10-5~1.0×10~(-3) mol·L~(-1)内与化学发光强度呈线性关系,检出限(3S/N)为1×10~(-6) mol·L~(-1)。按标准加入法对复方磺胺脒片进行回收试验,回收率为94.3%~98.5%,测定值的相对标准偏差(n=6)小于4.0%。     

铁氰化钾-鲁米诺体系后化学发光反应及其分析应用研究-分子印迹-后化学发光法测定双嘧达莫

研究了双嘧达莫在铁氰化钾-鲁米诺化学发光反应体系中的后化学发光反应, 并在研究其反应的动力学性质、化学发光光谱、荧光光谱以及一些相关问题的基础上, 探讨了反应机理; 合成了双嘧达莫的分子印迹聚合物, 以此聚合物为分子识别物质, 利用铁氰化钾-鲁米诺-双嘧达莫后化学发光体系, 建立了测定双嘧达莫的高选择性分子印迹-后化学发光分析方法. 所建方法的线性范围为1.0×10-8-1.0×10-6 g/mL(r=0.999 2), 检出限为3×10-9 g/mL, 相对标准偏差为2.7%(1.0×10-7 g/mL双嘧达莫, n=11).     

氯胺酮分子印迹聚合物的制备与性能研究

为了制备对氯胺酮具有选择性识别能力的分离富集材料,实验采用本体聚合法,以氯胺酮为模板,(-甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EGDMA)为交联剂,在优化了功能单体与交联剂的用量后,制备了一种吸附性能理想的分子印迹聚合物。该印迹聚合物在氯胺酮浓度为100μg·m L~(-1)的甲醇溶液中对氯胺酮的吸附量为33.8 mg·g~(-1),印迹因子为2.02,而且可以再生与重复使用。     

分子印迹磁固相萃取/气相色谱法分析环境水样中5种酰胺类除草剂残留

以丁草胺为假模板分子,丙烯酰胺为功能单体,利用四氧化三铁磁性纳米微球成功制备了具有特异性识别能力的磁性分子印迹聚合物。采用透射电子显微镜、红外光谱和振动样品磁强计对印迹聚合物进行表征,结果显示,分子印迹聚合物成功包裹在四氧化三铁表面。印迹聚合物对5种酰胺类除草剂均有特异性识别作用。以磁性分子印迹聚合物为基础,建立了酰胺类除草剂的气相色谱检测方法。方法学验证表明该方法具有良好的回收率(85.0%~99.5%)和精密度(RSD为2.8%~5.0%,n=5),线性范围为0.1~500μg·L~(-1),检出限为0.02~0.05μg·L~(-1)。该方法能够应用于农田灌溉用水等环境水样的测定。     

磁性氧化石墨烯壬基酚分子印迹聚合物的制备及吸附性能研究

以磁性氧化石墨烯(Fe3O4@GO)为载体,2-乙烯基吡啶为功能单体,乙二醇二甲基丙烯酸酯为交联剂,利用表面聚合技术制备了对壬基酚(NP)有特异吸附性能的分子印迹聚合物。电子显微镜表征和静态吸附试验结果表明:分子印迹聚合物已修饰在Fe3O4@GO表面,且该聚合物对壬基酚有良好的吸附性能,其最大吸附量为27.99g·kg~(-1)。以该分子印迹聚合物为固相萃取材料,乙腈为上样溶剂、甲醇-乙酸(9+1)溶液为洗脱剂,采用高效液相色谱法对牛奶塑料包装袋中壬基酚进行富集和测定。NP质量浓度的线性范围为2.0~100μg·L~(-1),检出限(3S/N)为0.34μg·kg~(-1)。加标回收率在86.1%~95.2%之间,测定值的相对标准偏差(n=5)小于5.0%。     

浮选富集—原子吸收光谱法同时测定水中铜铅镉银

研究了浮选技术在富集水中铜铅镉银的应用,将这一技术与火焰原子吸收光谱法相结合,提高了灵敏度,操作简便.方法检出浓度铜为lμg·L~(-1),铅为10μg·L~(-1),镉为0.5μg·L~(-1),银为0.5μg·L~(-1),相对标准偏差和回收率均很满意.     

流动注射-化学发光法测定氢化可的松

在一片聚甲基丙烯酸甲酯(PMMA,50mm×40mm×3mm)上用激光雕刻机雕刻一条宽200μm,深100μm,长9 cm的蜿蜒形流通池,其上盖以另一片大小相同的PMMA并在1.6MPa压力和108℃温度条件下使之结合成一体,从而制成了微流动注射芯片。基于氢化可的松对鲁米诺-铁氰化钾化学发光体系的增敏作用,提出了微流动注射芯片-化学发光法测定氢化可的松含量的方法。当化学发光体系中鲁米诺的浓度为8.0×10~(-5)mol·L~(-1)、铁氰化钾浓度为4.0×10~(-5)mol·L~(-1)、体系的pH值为12时,氢化可的松发光强度的增加值与其质量浓度在8.0×10~(-5)～8.0×10~(-2)g·L~(-1)范围内呈线性关系,检出限(3S/N)为4.0×10~(-5)g·L~(-1)。方法应用于食品中氢化可的松残留量的测定,回收率在96.5%～104.0之间。     

识别牛血红蛋白的分子印迹电化学传感器的制备与研究

采用电化学聚合物法制备了一种用于识别牛血红蛋白(BHb)的分子印迹电化学传感器。玻碳电极表面经电化学法沉积一层纳米金,接着自组装一层L-半胱氨酸,对修饰电极表面功能化,引入氨基和羧基,增加蛋白质印迹识别位点,以BHb为模板,采用电化学诱导的丙烯酰胺氧化还原聚合反应形成分子印迹聚合物层,模板蛋白分子经洗脱形成分子印迹电化学传感器。其产生的电化学信号的变化与BHb的质量浓度在1.0~1.0×103 mg·L~(-1)范围有直接的关系,检出限(3σ)达0.5mg·L~(-1)。这种新型传感器具有较高灵敏度,可用于目标蛋白的识别。     

沉淀聚合法合成拟除虫菊酯类分子印迹聚合物及其吸附性能研究

采用沉淀聚合法,以拟除虫菊酯的结构类似物二苯醚-联苯共晶作为替代模板,优化得到最佳的拟除虫菊酯类分子印迹聚合物合成条件:模板分子(二苯醚-联苯共晶)、功能单体(4-乙烯吡啶)、交联剂(乙二醇二甲基丙烯酸酯)的摩尔比为1∶6∶20,反应温度为70℃,引发剂用量为1%。将合成的分子印迹聚合物通过扫描电镜进行表征,并对吸附性能进行测试,其对60μg·mL~(-1)的二苯醚-联苯共晶的最大吸附量为6 041μg·g~(-1),且在7 h后达到吸附平衡。通过选择性实验得到印迹聚合物对毒死蜱、联苯菊酯、甲氰菊酯、氯菊酯、氯氰菊酯、氰戊菊酯的吸附量分别为259、316、311、271、305、298μg·g~(-1),而非印迹聚合物的吸附量则为169、188、181、183、151、142μg·g~(-1),印迹聚合物的选择性能明显高于非印迹聚合物。     

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%.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

A general synthesis of previously unknown semicarbazone-based α-amidoalkylating reagents, 4-(tosylmethyl)semicarbazones, has been developed. The synthesis involved three-component condensation of semicarbazones of aliphatic or aromatic aldehydes with the same or other aldehydes and p-toluenesulfinic acid. The scope and limitations of this reaction were investigated. The compounds obtained were demonstrated to be an efficient α-(4-semicarbazono)alkylating agents. They were reacted with H- (sodium borohydride), O- (sodium methylate), S- (sodium phenylthiolate), N- (pyrrolidine, sodium succinimide), P- (trialkyl phosphites), and C-nucleophiles (sodium diethyl malonate) to give the corresponding products of the tosyl group substitution, 4-substituted semicarbazones, including analogues of nitrofurazone. Among the prepared compounds tested in vitro for antibacterial and antifungal activity, three nitrofuryl-containing semicarbazones exhibited high biological activities with minimum inhibitory concentration (MIC) values of 8–32 μg/mL.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

A small library of new chiral bidentate hydroxyalkyl-imidazolium salts 1 is conveniently synthesized on multi-gram scale from inexpensive and commercially available chiral pool amino acids. The corresponding carbenes, generated by deprotonation of imidazolium salts 1, in combination with palladium(II) chloride were tested in the Mizoroki–Heck coupling reaction. The most significant results in terms of yields and reactivities were achieved with low catalyst loading. The catalytic activities of these imidazolium salts were also investigated in the asymmetric addition of diethylzinc to benzaldehyde. The use of MgO nanoparticles as an additive in conjunction with these ligands played a crucial role in increasing the efficiency of these reactions.     

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.     

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.     

Microwave-assisted copper-catalyzed stereoselective ring expansion of three-membered heterocycles with α-diazo-β-dicarbonyl compounds

Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular S_N2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.     

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.