土壤中多种有机氯及拟除虫菊酯类农药的GC-ECD测定

气相色谱法同时测定土壤中多种有机氯及拟除虫菊酯类农药。对土壤的分析结果：有机氯农药的检出限0．001～0、003μg／mL，拟除虫菊酯类农药检出限0.008～0．02μg／mL，线性相关系数0．9978～0．9999。用y（石油醚）：V（丙酮）=3：1超声波提取，有机氯农药回收率94．2％～124．0％，相对标准偏差为3．3％～8．8％（n=5）；拟除虫菊酯类农药回收率95．2％～118．3％，相对标准偏差为5．7％～7．1％（n=5）；方法适用于土壤样品中农药残留测定。     

左旋氧氟沙星的荧光光谱法研究

提出了一种测定左旋氧氟沙星（LEV）的荧光光谱新方法。该法基于电子受体氯冉酸（CL）和2,3-二氰-5,6-二氯-1,4-对苯醌（DDQ）与电子给体左旋氧氟沙星之间的荷移反应,显示这两种受体能强烈增敏LEV的荧光强度。对影响反应的不同变量和参数进行了研究,建立了两种荧光光谱法测定LEV的新体系：（1）CL体系,线性范围为0．06～3．6μg／mL,检出限为0．02μg／mL;（2）DDQ体系,线性范围为0．12～2．2μg／mL,检出限为0．04μg／mL。所提方法已用于制剂中左旋氧氟沙星含量的测定,回收率分别为99．72％～99．36％和99．36％～98．86％。     

DNA荧光探针—荧光素-中性红体系的研究

基于DNA对荧光素(FL)-中性红(NR)分子间荧光能量转移的抑制作用，以荧光素-中性红为荧光探针，考察该探针与DNA的结合反应，建立了准确测定DNA的新方法，在pH＝6.5条件下，hsDNA、ctDNA和smDNA的浓度与荧光素-中性红体系的荧光比值变化量Δ(Fd／Fa)成线性关系，响应线性范围分别为0．25-6．25μg／mL、0．10-5．00μg／mL、0．10-4．00μg／mL，0.025μg/mL和0．023μg／mL；分析测定了DNA合成样品，回收率91．3％-101．4％，相对标准偏差小于4．2％．     

Cy-5标记脱氧核糖核酸荧光毛细分析法的研究

在荧光毛细分析法（FCA）的基础上开发了一种用于DNA快速检测的DNA-FCA法。在毛细管内表面将DNA探针固定化，制成荧光毛细生物反应器（DNA-CBR）。测定时，用DNA-CBR吸入含Cy-5标记的靶DNA样品液进行杂交反应，然后在646nm激发波长、664nm发射波长下进行荧光测定；Cy-5标记的靶DNA浓度在0．1～1．0μmol／L之间线性良好（y=139．73x＋39．613，r=0．9985）；RSD〈5．5％；检出限为0．17pmol，样品用量10μL；DNA-CBR能够重复使用6次。本方法可用于靶DNA的定性和定最检测。     

微波消解-氢化物发生原子荧光光谱法同时测定化肥中砷、汞含量

采用微波消解样品前处理手段以及双道原子荧光光度计,建立了微波消解一氢化物发生原子荧光光谱法同时测定化肥中砷、汞含量的方法。通过试验确定了样品前处理方法,对负高压、灯电流,载气、屏蔽气、原子化器高度、酸度等测试条件进行了优化。在优化的工作条件下,砷、汞含量分别在0-50ng／mL和0—1．0ng／mL范围内与荧光强度呈良好的线性关系,线性相关系数分别为0．9996,0．9996,检出限分别为0．085,0．008ng／mL,回收率分别为88．8％～107．4％,90．0％～120％,测定结果的相对标准偏差均小于7％（n=6）。     

酶催化-荧光猝灭法测定药物中的姜黄素

酪氨酸在辣根过氧化物酶催化下被H2O2氧化为强荧光物质S,姜黄素对其荧光产生猝灭作用,据此建立了测定姜黄素的新方法。姜黄素浓度c在0．10～16．0μg/mL范围内与F0／F（F和F0分别为姜黄素存在和不存在时产物S的荧光强度）呈线性关系,线性回归方程c=5．4552F0／F-5．4860,线性相关系数r=0．9996,检出限为0．02μg/mL,测定结果的相对标准偏差为0．79％（n=10）,加标回收率为94．7％～102％。研究了pH值、各物质的量、反应时间、干扰离子等对测定的影响。该法可用于药物中姜黄素含量的测定。     

离子色谱法测定土壤中植物激素乙烯利

土壤样品中的乙烯利在IonPac AS14分离柱（4mm）,（3．5mmol Na2CO3＋1．0mmol NaHCO3）／L淋洗液的淋洗条件下得到较好的分离。在0～10μg／mL的范围内标准曲线呈线性,检出限为（0．08μg／mL）。精密度好,10．266μg／mL时,保留时间的RSD=0．86％;峰高的RSD=1．1％;峰面积的RSD=1．0％。在此条件下,其它阴离子对乙烯利的检测不干扰,样品的加标回收率为85．6％～87．9％。     

胶束增敏荧光光谱法测定吡哌酸

采用不同表面活性剂对吡哌酸在胶束体系中的荧光性质进行了研究，发现在酸性介质中十二烷基硫酸钠(SDS)对吡哌酸有较强的增敏作用，据此建立了胶束增敏荧光光谱法测定吡哌酸的新方法。方法线性范围为0．07-0．36μg／mL，检出限为0.04μg／mL，平均回收率为98．6％-101．3％，相对标准偏差为1．1％-1．2％。样品测定结果令人满意。     

水杨醛缩7-氨基-8-羟基喹啉-5-磺酸催化荧光法测定痕量钒(Ⅴ)

水杨醛缩7-氨基-8-羟基喹啉-5-磺酸（简称S7N8Q5S）在酸性介质中分解，产物呈现荧光，V（V）对该反应具有催化作用，本文建立了催化荧光法测定痕量钒的新方法。体系在PH=2的柠檬酸钠-盐酸缓冲溶液中，λex／λem=342／499（nm）。测定V（V）的最佳反应条件为0.04％S7NSQ5S5.0mL，5％KBrO35．0mL，缓冲溶液5．0mL，90℃加热5min。V（V）含量在12.0～40.0μg／L的范围内有良好的线性。将该方法用于钒铬钢样品及水样中痕量钒的测定，结果满意。本文还详细探讨了反应机理。     

高效液相色谱法同时测定调味料中的8种合成着色剂

建立一种同时测定调味料中8种合成着色剂的高效液相色谱分析方法。样品经30％甲醇水溶液提取,采用Diamonsil—C18柱（250mm×4．6mm）,以甲醇-1．55g／L乙酸铵为流动相,在最佳梯度洗脱条件下对8种合成着色剂进行分离,二极管阵列检测器检测,外标法定量。8种合成着色剂的线性范围为0．5～10．0μg／mL,回收率为95．0％～101％。对样品进行6次重复测定,峰面积测定结果的相对标准偏差为0．84％-3．51％（n=6）。     

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.     

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.     

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.     

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.     

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.