中空纤维协同液相微萃取在4种莨菪碱分析中的应用

利用协同液相微萃取方法初步探讨氢溴酸山莨菪碱、硫酸阿托品、氢溴酸东莨菪碱和丁溴酸东莨菪碱的优势构象;阐明有机溶剂对4种莨菪碱的萃取选择性和协同萃取作用机理;探讨中空纤维与莨菪碱形成电荷转移超分子对萃取效果的影响以及4种莨菪碱结构中N原子的亲电能力;结合高效液相色谱技术测定药物制剂中4种莨菪碱的含量。4种莨菪碱的线性范围均为0.05～5mg/L(r0.99),方法RSD小于7%,消旋山莨菪碱片和颠茄片中平均回收率分别为95.0%～119.0%和93.0%～95.0%,氢溴酸山莨菪碱和丁溴酸东莨菪碱检出限为0.03mg/L,硫酸阿托品和氢溴酸东莨菪碱检测出限为0.01mg/L。     

示波极谱滴定法测定生物碱氢溴酸盐类药物

以ＡｇＮＯ３作滴定剂，ＫＮＯ３和磺基水杨酸为极谱底液，采用交流示波极谱滴定法测定氢溴酸山莨菪碱、氢溴酸东莨菪碱、氢溴酸加兰他敏三种生物碱氢溴酸盐类药物的含量。该法到目前为止未见报道，具有快速、准确、终点直观的特点。     

离心式固相微萃取与液相色谱-质谱联用测定尿样中莨菪烷生物碱

建立了离心式固相微萃取与液相色谱-质谱联用(LC-MS)同步测定尿样中4种莨菪烷烃类生物碱(山莨菪碱、氢溴酸樟柳碱、甲溴东莨菪碱和丁溴东莨菪碱)的方法。样品经C18微柱富集、分离解吸后进行LC-MS测定,前处理过程用时5 min。结果表明,山莨菪碱、氢溴酸樟柳碱和丁溴东莨菪碱在0.1～50μg/L浓度范围内线性关系良好,甲溴东莨菪碱线性范围为0.5～50μg/L,相关系数(R²)均大于0.99。4种莨菪烷碱的检出限(LODs)和定量限(LOQs)分别为0.02～0.15和0.08～0.50μg/L。同一柱、不同柱之间萃取10μg/L莨菪烷碱的精密度良好,相对标准偏差(RSDs)均低于10%。在尿样中分别添加4, 20,80μg/L 3个浓度水平的莨菪烷碱,回收率为80.2%～99.6%,无明显基质效应。该方法适用于生物流体中莨菪碱类物质的同步测定。     

高效液相色谱法测定痛安宁胶囊中东莨菪碱的含量

1　引　　言痛安宁胶囊系由洋金花、蟾酥等 7味中药材组成的复方制剂。具有温经散寒、活血化瘀、通络止痛等作用。为有效的控制成品质量 ,选定该制剂中君药洋金花所含主要有效成分东莨菪碱为定量指标 ,采用高效液相色谱法 ,对东莨菪碱进行定量分析。方法准确、专一 ,适用于该制剂的质量分析检验。2　实验部分2 1　仪器与试剂　ＬＣ 1 0ＡＴｖｐ高效液相色谱仪 (日本岛津公司 ) ;色谱工作站 (大连化学物理研究所 )。氢溴酸东莨菪碱对照品 (中国药品生物制品检定所 ) ;乙腈 (优级纯 ) ;水为超纯水 ;其余试剂均为分析纯。2 2　实验方法　 (1 …     

毛细管电泳法同时测定复方苦参注射液中三种生物碱含量

应用毛细管电泳法测定了复方苦参注射液中苦参碱、氧化苦参碱、槐定碱的含量。毛细管电泳条件为 :未涂层石英毛细管 ( 5 7cm× 5 0 μm i.d.) ,分离电压为1 2 .5 k V,0 .2 mol/ L Tris- 40 mmol/ L磷酸二氢钠 ( p H5 .5 0 ) - 2 0 %异丙醇为缓冲液 ,检测波长 2 0 0 nm,氢溴酸东莨菪碱为内标。结果表明 ,该法简便、快速、准确 ,重现性好。     

微流控芯片测定丁溴东莨菪碱注射液中丁溴东莨菪碱

建立了微流控芯片非接触电导检测法测定丁溴东莨菪碱注射液中丁溴东莨菪碱含量的方法。优化选择3 mmol/LHAc+2 mmol/LNaAc(pH4.5)为缓冲溶液,1.0 mmol/Lβ-CD为添加剂,分离电压为2.00 kV,进样时间为10 s,丁溴东莨菪碱在2 min内可得到较好分离,线性范围为20～250μg/mL(r=0.998),检出限为6.0μg/mL(S/N=3),RSD为2.1%,加标回收率为97.0%～99.6%。     

高效液相色谱法同时测定双酚伪麻干混悬剂中的盐酸伪麻黄碱和氢溴酸右美沙芬

建立了可同时测定双酚伪麻干混悬剂中盐酸伪麻黄碱和氢溴酸右美沙芬含量的反相高效液相色谱方法。样品先经甲醇溶解,过滤,然后以Lichrospher C6H6化学键合硅胶为固定相、乙腈-水-H3PO4（体积比为50∶50∶0.1,pH 2.5,内含1 g/L十二烷基硫酸钠)为流动相进行色谱分离,在220 nm处定量测定。结果表明,氢溴酸右美沙芬、盐酸伪麻黄碱的质量浓度分别为1.03~206 mg/L和5~200 mg/L时,其峰面积与质量浓度的线性关系良好;批内(n=7)测定的平均相对标准偏差（RSD）分别为1.8%和1.0%,批间(n=5)测定的RSD分别为2.2%和1.5%;对双酚伪麻干混悬剂中氢溴酸右美沙芬、盐酸伪麻黄碱测定回收率分别为100.0%~101.8%和95.7%~98.7%。该法适用于双酚伪麻干混悬剂中氢溴酸右美沙芬和盐酸伪麻黄碱的质量控制及含量测定,方法准确,操作简便。     

Na2EDTA滴定法测定粗二氧化碲中铅含量

建立了用氢溴酸消除锑、砷、锡干扰,用硫酸将铅形成硫酸铅沉淀,再用EDTA络合滴定法测定粗二氧化碲中铅量的方法。试样用硝酸、盐酸溶解,用硫酸沉淀铅,氢溴酸消除锑、砷、锡的干扰后,过滤分离其他共存元素,以乙酸-乙酸钠缓冲溶液溶解硫酸铅沉淀,在pH=5.0～6.0时,以二甲酚橙作指示剂,用Na_2EDTA溶液滴定溶液中铅含量。实验结果表明,氢溴酸加入量为15mL,酒石酸加入量为10mL,沉淀体积为50～60mL,沉淀时间1h以上时,方法相对标准偏差(RSD)在0.10%～1.1%,加标回收率为97.1%～102%,满足粗二氧化碲中铅量的生产控制检测要求。     

二溴荧光素-N-氯代丁二酰亚胺化学发光体系测定片剂及人血浆中的氢溴酸右美沙芬

研究发现,碱性溶液中,二溴荧光素可吸收N-氯代丁二酰亚胺(NCS)氧化氢溴酸右美沙芬反应的化学能而产生化学发光,从而构建了二溴荧光素-NCS-氢溴酸右美沙芬化学发光体系.利用该体系建立了测定氢溴酸右美沙芬的流动注射化学发光新方法.方法线性范围是9.0×10-10～2.0×10-7 g/mL(r=0.9992),检出限为7.0×10-10 g/mL,对2.0×10-8 g/mL氢溴酸右美沙芬溶液进行11次平行测定的相对标准偏差(RSD)为1.6%.该法已用于片剂及人血浆中氢溴酸右美沙芬含量的测定,结果令人满意.在对有关反应的动力学性质、化学发光光谱及有关物质的紫外吸收光谱和荧光光谱研究的基础上,推断出可能的反应机理.     

流动注射-化学发光法测定药物中氢溴酸右美沙芬

试验发现由氢溴酸右美沙芬(D-MPHB)与高锰酸钾在5.0 mmol·L-1硫酸介质中反应所产生的较弱的化学发光强度因一定量的亚硫酸钠的存在而明显增强,且其化学发光的相对强度与D-MPHB浓度在1.0×10-5～1.0×10-1·L-1范围内呈线性关系,检出限(3S/N)为3.5×10-6g·L-1,根据这些结果并应用流动注射技术,提出了FI-CL法测定药物中氢溴酸右美沙芬的方法.应用所提出的方法分析了一种氢溴酸右美沙芬滴鼻液,测得其中D-MPHB的含量与标准值相符.以此药物为基体对方法的精密度及回收率作了试验,测得其相对标准偏差(n=5)均小于1.5%,回收率在99.7%～102.8%之间.     

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%.     

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.     

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.     

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.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

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.