葫芦巴碱标准物质的研制

研制葫芦巴碱标准物质。分别采用质量平衡法和定量核磁法两种不同原理方法对葫芦巴碱标准物质的纯度进行定值。利用高效液相色谱法对葫芦巴碱标准物质的均匀性和稳定性进行考察。对葫芦巴碱标准物质纯度定值结果的不确定度进行评定。结果表明,葫芦巴碱标准物质的纯度定值结果为99.31%,扩展不确定度为0.4%(k=2)。研制的葫芦巴碱标准物质量值准确,均匀性和稳定性符合二级标准物质技术要求。     

黄豆黄素纯度标准物质研制

建立黄豆黄素纯度标准物质的研制方法。选择纯度大于98%（质量分数）的黄豆黄素标准品作为标准物质候选物,通过加热和冷冻干燥去除多余的水分。通过红外、质谱、核磁氢谱进行结构确证和表征后分装,采用质量平衡法进行均匀性和稳定性检验。结果显示,标准物质均匀性良好,在常温条件下保存12个月稳定;采用质量平衡法和定量核磁法进行纯度定值,质量平衡法的定值结果为99.09%,定量核磁法的定值结果为99.13%,取平均值99.1%作为最终定值结果;对定值、均匀性和稳定性引入的不确定度进行了系统评定,扩展不确定度为0.3%(k=2)。研制的黄豆黄素纯度标准物质已申报国家一级标准物质,编号为GBW 10171。该标准物质可用于食品、保健品、饲料中黄豆黄素含量检测。     

牛磺酸标准物质的研制

研制了牛磺酸标准物质。采用红外光谱(IR)法对牛磺酸进行定性,经均匀性初检后分装成200瓶样品,利用超高效液相色谱(UPLC)及高效毛细管电泳(HPCE)两种不同原理的方法进行定值,从样品中随机抽取15瓶采用超高效液相色谱(UPLC)法进行了均匀性检验,经F检验表明在95%的置信区间范围内样品均匀性良好,稳定性考察按照短期稳定性(1个月)和长期稳定性(12个月)分别进行,结果表明在考察期间样品稳定性良好。评定了定值结果的不确定度,牛磺酸标准物质定值结果为99.6%,相对扩展不确定度为0.5%(k=2)。     

甲苯纯度标准物质制备

研制了甲苯纯度标准物质。以市售甲苯高纯试剂为原料,对其结构及纯度进行验证,最终将其分装至1mL安瓿瓶。采用质量平衡法和定量核磁共振法两种不同原理方法对甲苯标准物质进行纯度定值。通过质量平衡法对特性量值进行均匀性检验、长期稳定性监测和模拟运输条件的短期稳定性监测,同时系统分析与评估了标准物质研制过程中定值、均匀性和稳定性引入的不确定度。结果表明,甲苯纯度标准物质的纯度值99.8%,扩展不确定度为0.2%(k=2),特性量值均匀性良好,12个月稳定性可靠。     

液相色谱仪检定用甲醇中胆固醇标准物质的研制

采用重量–容量法制备了液相色谱检定用200μg/m L的甲醇中胆固醇标准物质,分别用F检验和回归曲线法对研制的标准物质进行了均匀性和稳定性检验,对定值结果的不确定度进行了评定。结果表明,研制的甲醇中胆固醇标准物质具有良好的均匀性和稳定性,定值结果的相对扩展不确定度为2%(k=2)。该标准物质可用于液相色谱仪示差折光检测器、蒸发光散射检测器的检定。     

氢化可的松纯度标准物质的研制

介绍纯度标准物质氢化可的松的研制方法.采用高效液相色谱法对该标准物质进行了定值及均匀性、稳定性检验.该标准物质定值结果为99.5%,扩展不确定度为0.2%,其均匀性和稳定性检验结果表明,该标准物质符合国家一级标准物质的技术要求.     

甲醇中丙烯酸乙酯溶液标准物质制备

研制特征量值为1 000μg/mL甲醇中丙烯酸乙酯溶液标准物质。分别利用气相色谱-质谱联用法、核磁共振波谱法和红外光谱法对丙烯酸乙酯标准品原料进行定性确认。采用质量平衡法对主成分含量进行量值核验，丙烯酸乙酯标准品纯度（质量分数）为99.842%，扩展不确定度为0.3%，量值在证书给出的不确定度范围内，因此采用证书标识量值作为原料标准值，证书中标识的不确定度作为原料不确定度。以丙烯酸乙酯标准品为原料，采用重量-容量法制备溶液标准物质，分别采用F检验和t检验对标准物质进行均匀性和稳定性检验，并对其定值结果的不确定度进行评定。结果表明，该标准物质均匀性和稳定性良好，有效期为12月，定值结果的相对扩展不确定度为2%(k=2)，可用于环境样品中丙烯酸乙酯分析方法的确认和评价以及仪器校准与检测质量控制。     

肌酐纯度标准物质的定值方法及其不确定度评定研究

通过定性及定量分析,研究了肌酐纯度标准物质的定值方法,并进行了定值分析的不确定度评定。首先使用三重四极杆质谱仪及核磁共振谱仪(氢谱)对肌酐样品进行定性分析,然后采用质量平衡法(包括液相色谱法、水分、灰分、挥发性物质和无机元素分析)与定量核磁共振法共同对肌酐纯度标准物质进行准确定值,最后对定值结果进行不确定度评定。肌酐的定值结果为99.7%,扩展不确定度为0.4%。该研究对于实际检测中肌酐的准确测定及临床上相关疾病的正确诊断治疗具有重要意义,且经过定值的肌酐纯品还可做定量核磁共振法的定量内标使用。定量分析后的肌酐经过均匀性检验和稳定性考察后可申报为国家标准物质。     

低温封接玻璃成分分析标准物质的研制

研制了低温封接玻璃成分分析标准物质,对标准物质的制备技术进行了研究。分别用F检验和t检验法对研制的标准物质进行了均匀性和稳定性检验,结果表明,研制的低温封接玻璃标准物质具有良好的均匀性和稳定性。采用6家实验室进行协作定值,对定值结果的不确定度进行了评定。各组分定值结果的相对扩展不确定度均小于5%(k=2)。     

宝藿苷Ⅰ纯度标准物质的研制

以淫羊藿提取物为原料,通过正相硅胶柱色谱和凝胶柱色谱等分离纯化手段,研制了宝藿苷Ι纯度标准物质。采用液相色谱–质谱法和核磁共振技术对宝藿苷Ⅰ纯度标准物质进行定性鉴定,利用高效液相色谱(HPLC)法和胶束电动毛细管色谱(MECC)法对宝藿苷Ι的纯度进行定值分析,同时利用HPLC法对宝藿苷Ι纯度标准物质进行均匀性检验与稳定性考察,通过F检验和t检验法对其均匀性进行检验,表明瓶间和瓶内均匀性一致,12个月稳定性检验结果的相对标准偏差为0.02%,说明宝藿苷Ι纯度标准物质是稳定的。对定值结果的不确定度进行了评价,研制的宝藿苷Ι纯度标准物质的定值结果和扩展不确定度分别为99.7%和0.3%(k=2)。     

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.     

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.