毛细管电泳高频电导法测定尿中MDMA及其代谢物

建立了尿样中MDMA及其代谢物MDA的毛细管电泳高频电导法检测分析方法。对电泳分离缓冲介质的种类、浓度、pH值以及分离操作电压和进样时间等实验条件进行了优化。缓冲液为2．5mmol／L NH4 Ac 0．5mmol／L HAc 2mmol／L SDS 10mmol／L β-CD,分离电压为15kV时,可实现较好的分离与检测。该法在2．5～80μg/mL范围内。MDMA和MDA线性相关系数r分别为0．998和0．999,检出限均为1．0μg/mL(S／N=3)。不同添加浓度水平尿样,日间和日内RSD均小于5％,回收率均在90％以上,适于法医毒物分析和临床药物监测的需要。     

高效液相色谱法测定人尿中神经鞘氨醇和二氢神经鞘氨醇

建立了一种检测人尿中神经鞘氨醇（So）和二氢神经鞘氨醇（Sa）的高效液相色谱方法（HPLC）。离心分离尿样中的片状剥落细胞,裂解后用乙酸乙酯萃取、邻苯二甲醛衍生,在HPLC系统中通过梯度洗脱用Nova-PakC18－RP色谱柱（15cm×3．9mm,4μm）分离、荧光检测器检测。So和Sa的检出限均为0．05ng（女性尿样0,075μg/L、男性尿样0．005μg/L）。分析从我国一个村在采集的40份尿样,女性尿样中So、Sa和Sa／So比值分别为1．29－13．58μg/L、0．25－3．13μg/L和0．15－0．25,男性尿样中分别为0．075~3．07μg/L、0.019－0．50μg/L和0．028～0．26。     

自制SPME涂层顶空萃取-气相色谱法分析废水中的芳香胺类化合物

建立了顶空固相微萃取与毛细管气相色谱法(HS—SPME-GC)测定废水中芳香胺类化合物的新方法。采用溶胶-凝胶法,自制新型单苯并冠醚探针．对萃取温度,萃取时间、解吸时间、离子强度和pH值等实验条件进行了优化选择：结果表明,该方法精密度良好,在标准溶液为0．1mg／L时,相对标准偏差(RSD)为4．0％～7．8％,线性范围为0．05～100μg/L,检出限达到0．005～0．01μg/L,加标回收率在97％～105％之间。运用该法对药厂废水中芳香胺类化合物进行了检测,结果令人满意由此可见,对环境中的芳香胺化合物进行检测,固相微萃取是一种快速、经济、有效的方法。     

在线还原富集火焰原子吸收光谱法测定环境水样中Cr(Ⅲ)和Cr(Ⅵ)的形态

采用单阀双阳离子交换树脂微柱并联，设计了双路采样逆向洗脱在线分离富集系统，该系统与原子吸收测量技术相结合，实现了在线分离富集-火焰原子吸收光谱法同时测定水中Cr(Ⅲ)和Cr(Ⅵ)，富集1min时，分析速度为60样/h，测定Cr(Ⅲ)和Cr(Ⅵ)的特征浓度分别为6．08μg/L和11．58μg/L(相当于1％吸收)，线性范围分别为0～1．0μg/mL和0～2．0μg/mL，对质量浓度为100μg/L的Cr(Ⅲ)和Cr(Ⅵ)测定的相对标准偏差分别为2．9％和3．0％、检出限分别为8．70和10．8μg/L。该法对实际水样加标回收率在94．5％～104．3％之间。     

人工尿样中芥子气-谷胱甘肽加合物的气相色谱-质谱法检测

该文以气相色谱-质谱法测定人工尿样中的芥子气-谷胱甘肽加合物的β-裂解产物1,1′-磺酰基二(2-甲巯基)乙烷(SBMTE)。采用固相萃取(SPE)及固相支持液-液萃取(SLE)两种方法对尿样中的SBMTE进行富集净化,并对两种方法的影响因素进行了优化。采用中等极性毛细管色谱柱(DB-17MS)分离,以电子轰击源(EI)质谱选择离子模式(SIM)检测,内标法定量。结果表明,以SPE/GC-MS方法检测,SBMTE在1~100μg/L范围内线性关系良好,相关系数r为0.998 4,检出限(LOD)为0.1μg/L,回收率大于90%;以SLE/GC-MS方法检测,SBMTE在2~150μg/L范围内线性关系良好,相关系数r为0.998 8,检出限为0.5μg/L,回收率大于90%。SPE方法适用于直接检测空白尿样中添加SBMTE或芥子气染毒真实尿样还原后样品的进一步净化处理,SLE方法可应用于芥子气染毒后真实尿样的确证检测和溯源性检测。     

对克伦特罗具有高特异性的酶联免疫吸附分析法研究

合成了克伦特罗(CL)半抗原2-(1-(4-氨基-3,5-二氯苯基)-2-(叔丁胺基)乙氧基)乙酸,采用活性酯法将半抗原与牛血清白蛋白偶联合成免疫原,经免疫、分离、纯化获得抗CL多克隆抗体,建立了对CL具高特异性的直接竞争酶联免疫吸附分析(dc-ELISA)法。本方法对CL检测的线性浓度范围为1.0×10!4～1.0 mg/L,定量检测下限为0.13μg/L。在尿样中添加CL标准至含量分别为10.0和1.0μg/L,dc-ELISA法检测的回收率分别为90.0%～115.9%和80.5%～112.4%;相对标准偏差(RSD)分别为7.1%和12.6%(n=10)。特异性实验结果表明:抗体与CL结构类似物沙丁胺醇(SAL)的交叉反应率<0.3%,因此本研究所制备的抗体可有效避免现有克伦特罗ELISA试剂盒、胶体金检测试纸假阳性率高的问题。     

啤酒中N-亚硝胺的SPME-GC-MS分析

研究了固相微萃取-气相色谱-质谱(SPME—GC—MS)联用方法检测啤酒中的N-亚硝基二乙胺(NDEA)、N-亚硝基吡咯烷(NPYR)、N-亚硝基二丁胺(NDBA)，采用聚二甲基硅氧烷／二乙烯苯(PDMS／DVB)萃取头，对影响固相微萃取效率的萃取时间、搅拌速度以及萃取方式等进行了优化，在优化实验条件下，方法的线性范围在12．5～250μg／L之间，相关系数r为0．9971～0．9995，检出限分别为NDEA4．50μg／L，NPYR8．99μg／L，NDBA2．27μg／L，NDBA回收率为86％～96％，相对标准偏差6．296～8．996，该法简化了前处理步骤，快速、方便．结果满意。     

离心式微固相萃取与液相色谱-质谱联用测定生物样品中新型合成大麻素

建立了离心式微固相萃取与液相色谱-质谱(LC-MS)联用，同步测定尿样和血样中5种新型合成大麻素的分析方法。尿样和血样稀释后在离心条件下通过C18离心式固相萃取柱，甲醇洗脱后LC-MS检测。结果显示，尿液基质中，5种合成大麻素在0.1～10μg/L浓度范围内线性关系良好，相关系数(R²)大于0.994，检出限(LODs)为0.01～0.02μg/L，定量限(LOQs)为0.05～0.08μg/L。全血基质中，5种合成大麻素在0.5～10μg/L浓度范围内线性关系良好，R²大于0.992, LODs为0.05～0.15μg/L, LOQs为0.18～0.50μg/L。在尿样和全血中分别添加0.5, 2, 10μg/L 3个浓度水平的合成大麻素，回收率分别为81.9%～108.3%和75.0%～95.5%，相对标准偏差(RSDs)低于10%。该方法可以满足生物样品中新型合成大麻素的分析需求。     

氨基甲酸酯类杀虫剂速灭威酶联免疫吸附分析方法研究

利用间-甲酚和β-丙氨酸合成了速灭威半抗原β-(间-甲基苯氧基羰基)氨基丙酸(HOM)。通过活泼酯法将HOM交联于牛血清白蛋白(BSA)和卵清蛋白(OVA)上;HOM-BSA为免疫原制备了速灭威的兔抗血清,ELISA法测得其效价高达1.28×106,交叉反应测定表明抗体方法特异性识别速灭威。对离子强度等影响因素进行了研究,确定了速灭威酶联免疫吸附分析方法(ELISA)的最佳工作条件,建立了定量测定速灭威的间接竞争ELISA方法,结果表明,该方法检测线性范围为1~10000μg/L;IC50为40.74μg/L;检出限为0.08~0.10μg/L;批内相对标准偏差为2.9%;批间相对标准偏差4.6%。土壤、稻谷和水中的平均添加回收率分别为80%、93.4%和107%。本研究建立了一种快速检测环境和农产品中速灭威残留的有效方法。     

顺序注射蒸气发生非色散原子荧光光谱法测定环境样品中痕量硒

建立了双泵顺序注射与氢化物发生非色散原子荧光光谱法联用,测定环境样品中痕量硒的方法。线性范围为0．25～10μg/L;检出限为0．02μg／L;测定精度(RsD)为0．97％(2μg／L,n=11)。每小时可分析80(240次注射)个样品。环境水样的回收率为97％～107％;对国家标准参考物质(GBW07405和GBW07314)的测定结果同推荐值一致。     

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.