茶叶中7种拟除虫菊酯农药残留量的检测方法

建立了一种同时测定茶叶中７种拟除虫菊酯农药残留量的气相色谱方法,试样中的拟除虫菊酯酯农药残留经丙酮－水（体积比８：１）体系萃取,正己烷反萃取,然后用乙腈萃取,弗罗里硅土柱净化,以ＧＣ－ＥＣＧ方法测定,外标法定量。实验表明,试样中添加质量分数（ｗ）０．０１＊１０＾－６－１．０＊１０＾－６含量水平的联苯菊酯,氯菊酯、氯氰菊酯、氰戊菊酯、溴氰菊酯,方法回收率为７５．０％－１０３．０％,最小检测含量０．１＊１０＾－７（ｗ）;试样中添加０．００２＊１０＾－６－０．２０＊１０＾－６含量水平的甲氰菊酯,方法回收率为９２．０％－１００．０％,最小检测含量０．２＊１０＾－８（ｗ）;试样中添加０．００１＊１０＾－６－０．１０＾－６含量水平的三氟氯氰菊酯,方法回收率为９６．０％－１０２．０％,最小检测含量０．１＊１０＾－８（ｗ）。同     

硫酸化高山红景天多糖(RSASL)的制备及鉴定

从高山红景天中分离出一种酸性杂多糖（ＲＳＡ）．该多糖由阿拉伯糖（Ａｒａ）、鼠李糖（Ｒｈａ）、半乳糖（Ｇａｌ）、木糖（Ｘｙｌ）、葡萄糖（Ｇｌｃ） 与半乳糖醛酸（ＧａｌＡ）组成,其单糖摩尔比为１．００∶３ ．２３∶０ ．２６∶０ ．３４∶０ ．８４∶１０．２４．用氯磺酸－吡啶法制备硫酸化高山红景天多糖（ＲＳＡＳＬ）．用离子色谱法测定ＲＳＡＳＬ 中Ｓ的质量分数为１１．０１％ ,其硫酸基取代度为０．８５．用红外光谱,紫外光谱,Ｓｅｐｈａｒｏｓｅ ＣＬ－４Ｂ柱层析,激光解吸电离飞行时间质谱等方法鉴定,ＲＳＡＳＬ均显示了多糖硫酸酯的特征     

灵芝多糖的结构分析

从灵芝菌丝和子实体热水提取液中分离和纯化得到两种多糖，凝胶过滤导析测得分了量分别为３．７×１０＾４和４．２×１０＾４。气相色谱分析表明菌丝体多糖含Ｄ－葡萄糖，Ｄ－半乳糖，Ｄ－甘露糖，Ｄ－木糖，Ｌ－岩藻糖，Ｌ－鼠李糖，其摩尔比为５．３５：２．６７：１．００：１．１９：０．３８：０．３７；子实体多糖含Ｄ－葡萄糖，Ｄ－半乳糖，Ｄ－甘露糖，Ｄ－木糖，Ｌ－阿拉伯糖，Ｌ－鼠李糖，其摩尔比为５．８２：２．２３；     

同时测定体液中咖啡因和茶碱的薄层色谱扫描法

研究了同时测定血清、尿样中的咖啡因和茶碱的薄层色谱定量法。在ＧＦ２５４硅胶板上，用乙酸乙酯－氨水（Ｖ乙酸乙酯∶Ｖ氨水＝９６∶４）的二元展开体系能将这两种生物碱有效地分离。其Ｒｆ值为咖啡因０．４６，茶碱０．１６。分离后的试样用薄层色谱扫描仪进行扫描定量，测定波长２７２ｎｍ，线性范围咖啡因０．００９７～１．９４μｇ，茶碱０．００９０～１．８０μｇ。血清及尿样的加标回收率在９５．８％～１０６．５％之间，相对标准偏差２．９５％～３．５０％。本法较为简便、快速、准确     

蔗渣水解液及发酵液中糖及糖醇的高效液相色谱分析

采用ＨＰＬＣ测蔗渣水解液及发酵液中木糖、木糖醇等。在ＳｐｈｅｒｉｓｏｒｂＮＨ２柱上用乙腈＋水（８０＋２０）分离，示差折光检测器检测， １５ｍｉｎ内同时分离测定木糖、木糖醇及其它五种糖。线性范围在 ０～７．５ ｇ／Ｌ，相对偏差小于４．１％。     

饮料食品中Ge－132和Ge~（4＋）含量测定研究

本文报告了在０．０１ｍｏｌ／ＬＣＴＡＢ体系中，以Ｆ－为掩蔽剂、苯芴酮显色、用分光光度法测定饮料食品中Ｇｅ－１３２含量，最低检测限０．０５４μｇ／ｍＬ；线性范围０．５４～２７．１４μｇ／ｍＬ；回收率９６．３％～１０１．５％，并确定了Ｇｅ－１３２摩尔吸收系数（ε）３．３９×１０４。用本法测定了康寿茶、矿泉水和博士奶中Ｇｅ－１３２含量，灵敏度高、重现性和准确度好。用盐酸化本体系，研究了二氧化锗（Ｇｅ~（４＋））的含量测定，其最低检测限０．０２１μｇ／ｍＬ；线性范围１．０～２１．０μｇ／ｍｌ；回收率９５．８％～１０２．８％，Ｇｅ－１３２不干扰。饮料食品中同时存在Ｇｅ－１３２和Ｇｅ（４＋）时，本体系可分别测定两者含量。     

高效液相色谱法测定烟草料液中的糖

研究了用蒸发光散射检测器检测，高效液相色谱法测定烟草料液中糖的方法。料液中的糖用固相萃取预分离，然后以Waters carbohydrate高效糖柱为固定相，V（乙腈）：V（水）=70：30作为流动相分离，蒸发光散射检测器检测；样品中鼠李糖、木糖、阿拉伯糖、果糖、甘露糖、葡萄糖、蔗糖、麦芽糖8种糖的加标回收率分别为：97．0％、95．6％、102％、102．1％、95．0％、101．8％、102．6％、97．8％；线性范围分别为：鼠李糖、果糖、葡萄糖、蔗糖0．1～20pg，木糖、阿拉伯糖、甘露糖、麦芽糖0．2～25μg。相对标准偏差均小于3．2％。方法的检出限达：鼠李糖20ng、木糖26ng、阿拉伯糖28ng、果糖14ng、甘露糖20ng、葡萄糖10ng、蔗糖12ng、麦芽糖15ng，用该方法测定了烟草料液中的糖。     

HP－50＋大口径毛细管气相色谱法测定水果中多种有机氯农药残留量

以ＨＰ－５０＋大口径毛细管柱为分离柱，ＧＣ－ＥＣＤ测定水果中１４种有机氯农残。方法的检测限为０．１×１０￣（－９）～２．０×１０￣（－９），回收率范围在８８．６％～１０５．８％，变异系数２．６％～１０．５％。样品前处理采用微量化学法。     

尖海龙与日本海马脂肪的提取和分析

本采用快速脂肪提取法取代索氏提取法，提取时间仅需４５ｍｉｎ提取率９８．８％以上，并利用５０ｍ×０．３５ｍｍｉ．ｄ，ＰＥＧ－２０Ｍ玻璃毛细管柱，分析了山东黄海海域尖海龙与日本海马脂肪中的脂肪酸，其中，尖海龙分离出５９个峰，鉴定了４２个，日本海马分离出５２个峰，鉴定了４１个，分别占脂肪酸总量的９７．３％和９８．０％，测得尖海龙脂肪中的ＥＰＡ＋ＤＨＡ占３１．０％，日本海马为１４．１％。     

茯苓菌核多糖的分离和结构分析

分别用０．９％ＮａＣｌ不溶液，热水，０．５ｍｏｌ／Ｌ ＮａＯＨ水溶液和８８％甲酸从新鲜茯苓菌核体中提取出５种多糖：ＰＣ１，ＰＣ２，ＰＣ２－Ａ，ＰＣ３和ＰＣ４．用ＩＲ，ＨＰＬＣ，ＧＣ，＾１ＨＮＭＲ和＾１３Ｃ ＮＭＲ等方法分析了它们的组成和结构。结果表明，ＰＣ１，ＰＣ２和ＰＣ２－Ａ由Ｄ－葡萄糖，Ｄ－木糖，Ｄ－甘露糖和Ｄ－半乳糖组成，ＰＣ１和ＰＣ２－Ａ含葡萄糖醛酸，其葡萄糖含量随提取过程的进行逐渐增加。     

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.