整体柱高效液相色谱法测定草甘膦原药中甲醛含量

建立了衍生化-高效液相色谱法对草甘膦原药中痕量甲醛含量进行测定的方法。样品中残留甲醛经超声波水浴提取，与2，4-二硝基苯肼衍生反应，生成的2，4-二硝基苯腙用反相整体柱色谱进行快速分离，在360nm紫外波长下检测，外标法定量。该分析方法在2．0～200mg/L浓度范围呈良好线性，添加回收率在88％～105％之间，相对标准偏差小于5％。样品中甲醛的最小检测浓度为0．5mg/kg。比较了整体色谱柱和常规C18反相柱分离效果，表明整体色谱柱可在1．5min内实现衍生化产物的快速分离并进行定性定量，同时发现相对于常规柱，采用整体柱提高了检测灵敏度约10倍。     

多功能柱净化-高效液相色谱法同时检测小麦中雪腐镰刀菌烯醇和脱氧雪腐镰刀菌烯醇

建立了小麦中雪腐镰刀菌烯醇（NIV）和脱氧雪腐镰刀菌烯醇（DON）的高效液相色谱同时检测方法。样品采用乙腈-水（体积比85：15）混合溶剂进行提取．通过多功能净化柱（MFC）进行一次性净化,以C18柱为分离柱,水-乙腈-甲醇（体积比90：5：5）混合溶剂为流动相进行高效液相色谱分离和检测。在小麦样品中,本方法在0．2～5μg／g添加范围内的凹收率为87％～99％;相对标准偏差为1．5％～8．3％;DON和NIV的检出限分别为0．12和0、16μg／g（5／N=3）。     

牡蛎中痕量有机氯农药残留量的分析方法研究

建立了同时测定牡蛎中16种有机氯农药残留量的前处理方法和气相色谱分析方法。在100℃的温度条件下,用加速溶剂提取（ASE）提取样品中的有机氯农药,用凝胶渗透色谱（GPC）结合Florisil柱净化,以RTX-5MS毛细管色谱柱分离、ECD检测器测定。结果表明,样品的加标回收率（n=3）为81％～110％,方法检出限为0．2～0．7ng／g,样品检测的相对标准偏差为2．9％～15．2％。     

多功能柱净化-高效液相色谱法检测谷物中的玉米赤霉烯酮

建立了玉米和小麦中玉米赤霉烯酮（ZEN）的多功能柱净化-高效液相色谱检测方法。样品经乙腈-水混合溶剂（V（乙腈）：V（水）=84：16）提取,通过多功能净化柱（MFC）进行一次性净化,以Symmetry^R C18柱为分离柱,甲醇-水（V（甲醇）：V（水）=68：32）为流动相进行高效液相色谱分离和检测。玉米赤霉烯酮的质量浓度在0．01～4．0μg／mL范围内呈良好线性,相关系数为0．9996。检出限为0．04μg／g,在0、04—5．0mg／kg添加范围内的回收率为87．5％～98．6％,相对标准偏差为1．5％～8．3％。     

高效液相色谱柱后化学衍生法测定食品中的VB1及叶酸含量

研究柱后化学衍生荧光检测高效液相色谱分离测定食品中维生素B1和叶酸的方法。采用C18柱,以含有3．5％乙腈的pH5．0磷酸盐缓冲溶液(0．05mol／L)作为流动相反相分离。色谱流出液在柱后与0．4％的过二硫酸钾溶液在线汇合后流经—Teflon管化学反应器时,维生索B1和叶酸转化为强荧光产物,由荧光检测器测定。在最佳条件下,进样20μL,维生素B1和叶酸工作曲线的线性范围分别为0．21～4．2mg／L和0．10～2．0mg／L,峰面积的相对偏差均为2．0％,回收率及实际样品测定结果满意。     

气相色谱质谱联用法对农产品中8种种衣剂农药残留的同时测定

应用气相色谱-质谱联用仪（GC-MS）建立了水果、蔬菜、粮谷等农产品中8种种衣剂农药残留的分析测定方法。样品用乙腈提取,通过石墨化碳或C18固相萃取小柱净化,经DB-5ms气相色谱柱分离,电子轰击电离（EI）、选择离子监测模式（SIM）对定量离子和定性离子进行MS测定。标准工作曲线范围0．02-0．5mg／L。样品中添加水平为0．005、0．010和0．020mg／kg时,回收率为74％～110％;相对标准偏差小于15％。检出限（S／N=3）为0．09～0．77μg／kg。     

加压溶剂萃取和在线检测可吸入固体颗粒物(PM10)中16种多环芳烃

建立了微池加压溶剂萃取（μ-PLE）-气相色谱在线联用测定可吸入固体颗粒物（PM10）中多环芳烃的方法和装置。研究了萃取压力在5～20MPa、萃取温度在50—200℃、萃取时间在2-15min对μ-PLE萃取效率的影响。实验结果表明：方法的回收率在24．3％-63％之间；对标准样品的检出限为2．2-9．5μg／L；对实际样品的检出限在0．01—2．03ng/m^3之间；相对标准偏差（RSD）为1．6％-26．4％。通过对萃取池小型化，利用毛细管气相色谱大体积柱内进样技术，实现了两者的在线联用。将萃取液全部转移到气相色谱中，样品利用率达到80％以上，检出灵敏度比现有样品预处理方法提高100倍以上，可以监测大气颗粒中短时间化学变化的有机成分。     

荧光色谱-柱后光化学衍生法测定食品中的黄曲霉毒素B1

采用免疫亲和层析柱吸附食品样品中的黄曲霉毒素B1,以荧光色谱-柱后光化学衍生法测定食品中黄曲霉毒素B1的含量。样品用甲醇-水溶液（体积比为7：3）混合,均质器高速搅拌提取,经免疫亲和层析柱纯化后,通过LachromC18色谱柱进行分离,以甲醇一水溶液（体积比为45：55）作为流动相,荧光检测器激发波长为360nm、发射波长为420nm,外标法定量。黄曲霉毒素B,的质量浓度在1～20ng／mL范围内与色谱峰面积线性关系良好,相关系数r=0．9998,检出限为0．1gg／kg。在3个添加水平下,样品的加标回收率在88．5％～97．9％之间,相对标准偏差均小于3％（n=6）。该方法操作简单、定量准确,可用于食品中黄曲霉毒素B．的定量定性检验。     

离子色谱法同时测定叶菜中的硝酸盐和亚硝酸盐

采用抑制型离子色谱法同时测定叶菜中的硝酸盐和亚硝酸盐的含量。色谱柱为Ionpac AS11柱，流动相为21mmol/L NaOH溶液，检测器为电导检测器（CD），流动相流速为1.0mL/min。该方法简便、快捷，准确度和灵敏度高，NO2^-和NO3^-的回收率分别为97％－105％和95％－104％，相对标准偏差RSD＜5．0％。同时考察了样品浸提时间对结果的影响。     

HPLC法测定西沙必利片的含量

建立了测定西沙必利片含量的HPLC法。以Kromasil Cl8柱为色谱柱、0．02mol／L磷酸二氢钾缓冲液(pH=4．5)-乙腈(体积比为70：30)为流动相，流动相的流速为0．8mL／min，检测波长为308nm。西沙必利的浓度在5-125μg／mL范围内与色谱峰面积呈线性关系，线性相关系数r=0．9998，测定结果的平均加标回收率为99．91％，相对标准偏差为0．33％。     

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.