流动注射化学发光法测定盐酸吗啉胍

二氯荧光素作为能量转移剂,N 溴代丁二酰亚胺氧化盐酸吗啉胍产生化学发光,十六烷基三甲基氯化铵对该体系具有强烈的增敏作用,据此建立了测定盐酸吗啉胍的流动注射化学发光分析法。研究了影响化学发光的各种因素,对机理进行了探讨。方法对盐酸吗啉胍响应的线性范围为 1. 0×10-5 ~0. 1g/L,检出限(3σ)为 3. 0×10-6 g/L,RSD为 2. 5% (5. 0×10-4 g/L,n=11)。本法用于盐酸吗啉胍片及杀菌剂中盐酸吗啉胍的定量分析,结果满意。     

流动注射-化学发光法测定盐酸洛美沙星

在酸性条件下盐酸洛美沙星可与Ce(Ⅳ)产生化学发光反应，罗丹明6G对该反应有较强的增敏作用。据此，建立了流动注射-化学发光法测定盐酸洛美沙星的新方法。该方法的线性范围为0．10～15．0mg／L，检出限为0．06mg／L，相对标准偏差(n=11，c=1．00mg／L)为1．2％，回收率为95％～102％。本法用于胶囊中盐酸洛美沙星含量的测定，分析结果满意。     

分子印迹复合膜对降糖药的拉曼光谱快速检测

基于分子印迹技术的特异性识别特点, 以假模板盐酸胍和4-(2-氨乙基)苯磺酰胺制备了2种分子印迹复合膜, 用其对保健品中的二甲双胍、 苯乙双胍和格列本脲进行吸附后, 采用拉曼光谱法实现了保健品中降糖药的富集与快速检测. 考察了膜制备过程中纳米银的加入对拉曼光谱的增强作用, 以及吸附样品浓度等的影响. 实验结果表明, 盐酸胍分子印迹复合膜吸附5 mg/mL以上的二甲双胍或苯乙双胍后具有明显的拉曼响应, 4-(2-氨乙基)苯磺酰胺印迹膜吸附10 mg/mL格列本脲后具有明显的拉曼响应. 所建立的分子印迹复合膜结合拉曼光谱检测方法可用于多种实际样品的检测.     

化学发光新体系测定盐酸洛美沙星

在碱性条件下盐酸洛美沙星对Luminol KIO4 钙黄绿素发光体系有强烈的抑制作用。据此建立了流动注射化学发光抑制法测定盐酸洛美沙星的新方法。该方法的线性范围为1 0～20mg L,检出限(3σ)为0 30mg L,相对标准偏差(n=10,ρ=5.0mg L)为0 9%。已用于胶囊中盐酸洛美沙星的测定,回收率为95%～106%。     

N-溴代琥珀酰亚胺-荧光素体系流动注射能量转移化学发光法测定妥布霉素

在碱性条件下,N-溴代琥珀酰亚胺(NBS)氧化妥布霉素,在荧光素增敏作用下发生化学发光。基于此,结合流动注射技术,建立了测定痕量妥布霉素的流动注射化学发光分析法。在优化的实验条件下,体系对妥布霉素的测定线性范围为0．2—100mg／L;检出限(3σ)为0．07mg／L;对5．0mg／L妥布霉素进行11次平行测定,其相对标准偏差为2．1％。将本法用于制剂和血样中妥布霉素的分析,结果令人满意。     

鲁米诺-高锰酸钾-苯酚化学发光体系研究

基于鲁米诺-高锰酸钾-苯酚体系很好的化学发光特性,建立一种测定苯酚的流动注射化学发光分析新方法。在最优化实验条件下,苯酚浓度在0．001—2．5mg／L范围内与化学发光强度呈良好的线性关系,标准曲线为ΔI=750．45C(mg／L) 1．4655(n=8,r^2=0．9998),检出限(3σ)为0．35μg/L;对0．05和0．5mg／L的苯酚进行11次平行测定,相对标准偏差(RSD)分别为0．6％和2．5％。应用本法于合成样品和工业废水中苯酚的测定,结果令人满意。     

鲁米诺-过硫酸钠化学发光体系测定硝苯地平

过硫酸钠在碱性条件下能氧化鲁米诺产生微弱化学发光,硝苯地平能大大增强此发光。基于此．建立起了一种直接测定硝苯地平的流动注射化学发光方法。该方法线性范围为0．05～5．0mg／L;检出限为0．017mg/L;相对标准偏差为2．8％(硝苯地平0．5mg／L,n=11)。利用该方法测定了硝苯地平片剂含量,结果令人满意。     

液相色谱-串联质谱测定降血糖功能食品中双胍类药物

建立了降血糖功能食品中二甲双胍和苯乙双胍的液相色谱-串联质谱测定方法。采用体积比1:1的甲醇-乙醇溶液超声提取降血糖功能食品降糖粉、奶粉、口服液、胶囊、清渴茶中的二甲双胍和苯乙双胍,提取液经WCX固相萃取柱净化后,以乙腈和2 mmol/L NH4Ac溶液(含0.1%甲酸)为流动相进行梯度洗脱,经Agilent ZORBAX Eclipse XDB-C18色谱柱分离,电喷雾正离子(ESI+)模式电离,多反应监测(MRM)模式检测,基质回收标准曲线定量。二甲双胍和苯乙双胍的定量限(LOQ)均为10.0μg/kg,在不同基质中添加水平为10.0,20.0,50.0μg/kg时,二甲双胍和苯乙双胍的平均回收率分别为92.7%～99.6%和91.3%～100.3%,RSD分别为2.1%～8.4%和1.1%～11%。本方法可用于降血糖功能食品中双胍类药物的测定和确证。     

反相流动注射-化学发光法测定氢化可的松

在碱性介质中,氢化可的松可被Fe(CN)6^3-氧化产生化学发光,奎宁对此发光反应有显著的增敏作用。据此,建立了反相流动注射-化学发光法测定氢化可的松的新方法。方法的线性范围和检出限分别为0．05．-50mg／L和0．02mg／L,相对标准偏差(n=11,C=1．0mg／L)为0．9％。方法用于药物中氢化可的松含量的测定,结果与标准方法分光光度法测定结果吻合。     

流动注射化学发光法测定氧乐果

基于氧乐果的水解反应和巯基化合物一铈(Ⅳ)的化学发光反应,以罗丹明B作为增敏剂,建立了痕量氧乐果的流动注射．化学发光分析方法。该方法的线性范围和检出限分别为0．04～14．00mg／L和0．02mg／L,相对标准偏差(n=11,ρ=1．00mg／L)为0．9％。该方法已用于废水水样的分析。     

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.     

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.     

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.     

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.