QuEChERS-超高效液相色谱-串联质谱法同时测定畜禽组织中6种黄曲霉毒素和杂色曲霉素

建立了QuEChERS前处理技术结合超高效液相色谱-串联质谱（UHPLC-MS/MS）检测畜禽组织中6种黄曲霉毒素和杂色曲霉素残留的分析方法。样品经20 μL β-葡萄糖苷酶酶解和10 mL乙腈-水（84：16,v/v）提取,然后用1.0 g氯化钠和1.0 g无水硫酸镁净化、5 mL正己烷脱脂,最后采用1 mL含5 mmol/L乙酸铵的乙腈-水溶液（80：20,v/v）复溶。以甲醇和5 mmol/L乙酸铵为流动相,在多反应监测正离子模式下进行检测,采用基质匹配标准曲线外标法进行定量分析。结果显示,6种黄曲霉毒素和杂色曲霉素在各自的范围内线性关系良好,相关系数（R²）>0.99,检出限（LOD,S/N=3）为0.007~0.30 μg/kg,定量限（LOQ,S/N=10）为0.02~0.91 μg/kg,加标回收率为77.3%~118.5%（n=6）。该法简单、快速,灵敏度高,适用于不同畜禽产品中6种黄曲霉毒素和杂色曲霉素的确证分析。     

用免疫亲和柱分离、高效液相色谱法测定花生和玉米中黄曲霉毒素的研究

建立了用免疫亲和柱分离净化、高效液相色谱法测定花生和玉米中黄曲霉毒素（ＡＦＴ）Ｂ＿１、Ｂ＿２、Ｇ＿１、Ｇ＿２的方法。采用６０％甲醇提取样品中的ＡＦＴ,氢氧化铁沉淀吸附除去样品液中大部分杂质,再经过亲和柱将ＡＦＴ截留,进一步与杂质分离,洗脱后,加三氟乙酸衍生化处理,反相高效液相色谱法分离定量。对样品中四种ＡＦＴ的最低可测下限浓度均为１μｇ／ｋｇ,样品加标５～１０μｇ／ｋｇＡＦＴ,回收率在７６．９％～１１３．６％范围内。     

高效液相色谱-质谱法同时测定曲霉菌代谢物中的黄曲霉毒素及其同系物

建立了同时检测曲霉菌代谢物中黄曲霉毒素和同系物的超高效液相色谱-线性离子阱质谱测定方法。寄生曲霉(菌株3.124)经PDA液体培养基培养,Qu ECh ERS方法提取净化后经线性离子阱(QTrap)质量分析器分析(正离子模式,多反应检测),检出3.124代谢物中黄曲霉毒素B1(AFB1)、黄曲霉毒素B2(AFB2)、黄曲霉毒素G1(AFG1)、黄曲霉毒素G2(AFG2)、O-甲基杂色曲霉素(MST)、杂色曲霉素(ST)6种真菌毒素。结果表明,6种代谢物在0.1~40μg/L范围内线型关系良好,相关系数均大于0.993,检出限在0.03~0.2μg/L之间,定量限在0.1~0.5μg/L之间。本方法 6种代谢物日内回收率为81.3%~92.1%,相对偏差(RSD)为4.3%~8.6%;日间回收率为81.8%~91.5%,RSD为4.0%~8.7%。方法可满足霉菌代谢物中黄曲霉毒素及其类似物的检测与确证的需要。     

关于液相色谱保留值公式的补充

本文介绍了液相色谱保留值公式研究的历史,根据色谱保留值公式的统一形式运用液相吸附公式得到ｌｎｋ＇＝Ａ＋Ｂｌｎ（Ｃ＿（Ｂ＿１）／θ＿（Ｂ＿１））＋ＣＣ＿（Ｂ＿１）。当强溶剂浓度Ｃ＿（Ｂ＿１）不至太低时有ｌｎｋ＇≈Ａ＋ＢｌｎＣ＿（Ｂ＿１）＋ＣＣ＿（Ｂ＿１）：作者证明了当强溶剂浓度Ｃ＿（Ｂ＿１）→０时,ｋ＇→常数,从而纠正了长期存在于色谱热力学理论中Ｃ＿（Ｂ＿１）→０,ｋ＇→∞的谬误。     

基于QuEChERS提取的液相色谱-串联质谱法测定干腌火腿中15种真菌毒素

建立了干腌火腿中15种真菌毒素(黄曲霉毒素B1、黄曲霉毒素B2、黄曲霉毒素G1、黄曲霉毒素G2、赭曲霉毒素A、橘青霉素、T-2毒素、HT-2毒素、蛇形菌素、新茄镰孢菌醇、疣孢青霉原、O-甲基杂色曲霉素、杂色曲霉素、环匹阿尼酸、青霉酸)多残留的液相色谱-线性离子阱质谱(QTrap LC-MS/MS)检测方法。火腿样品经含1%甲酸的乙腈水溶液提取,Qu ECh ERS方法净化后,以含0.1%甲酸和9.9%乙腈的5 mmol/L乙酸铵水溶液(A)与含0.1%甲酸的乙腈(B)为流动相,经Eclipse Plus C18色谱柱(3.0 mm×100mm,1.8μm)分离,以多级反应监测(MRM),通过信息相关扫描方式(IDA)触发增强子离子扫描(EPI),结合建立的15种真菌毒素的标准谱图库检索的多模式进行分析。结果表明,15种真菌毒素在0.05~200μg/L范围呈良好线性,相关系数均大于0.993,定量下限为0.05~2.5μg/kg。样品在1倍、2倍、10倍定量下限3个加标水平下的平均回收率为79.1%~95.5%,相对标准偏差(RSD)为3.2%~12.8%。该方法灵敏、简便、准确,可用于干腌肉类中真菌毒素的检测分析。     

高效液相色谱法检测人肝组织中黄曲霉毒素

以人肝癌组织为研究材料,丙酮、氯仿为主要抽提溶剂,建立了用高效液相色谱技术检测肝组织中黄曲霉毒素Ｂ＿１的方法。采用μ－Ｐｏｒａｓｉｌ色谱往,氯仿、环己烷、乙腈、异丙醇为流动相,荧光检测器检测,激发波长３６５ｎｍ,发射波长４３５ｎｍ。方法的平均回收率为９６．８５％,变异系数为４．５２％,最低检测限为０．０５ｎｇ。１０例肝癌组织中有７例检出５。４９～７３．７０ｎｇ／ｇ不等的黄曲霉毒素Ｂ＿１。方法快速、准确、灵敏度高。     

BTMPPA与HPMBP协同萃取稀土元素（Ⅲ）的研究

研究了二（２，４，４－三甲基戊基）膦酸（ＢＴＭＰＰＡ，ＨＬ）和１－苯基－３－甲基－４－苯甲酰基吡唑酮－５（ＨＰＭＢＰ，ＨＡ）的苯溶液在不同矿物酸介质中，对稀土元素（Ⅲ）的ＡＡ类协同革取。以Ｎｄ￣（３＋）、Ｙｂ￣（３＋）为例，研究了ＢＴＭＰＰＡ－ＨＰＭＢＰ苯溶液从ＨＮＯ＿３介质中协同萃取稀土元素（Ⅲ）的机理。用斜率法确定了协萃配合物组成为Ｎｄ（ＨＬ＿２）Ａ＿２、Ｙｂ（ＨＬ）２）＿２·Ａ·ＨＡ，计算了协萃平衡常数。     

间接法电合成2-甲基丁酸的研究

以２＿ 甲基＿１＿ 丁 醇为原料 ,四丁基 硫酸氢铵（ Ｔ Ｂ Ａ Ｓ） 或 四丁 基高 氯酸 铵（ Ｔ Ｂ Ａ Ｐ） 为 相转移催化 剂,在硫 酸酸性 Ｃｒ（ Ⅵ） 氧 化媒质中 氧化合成 ２＿ 甲基丁 酸．由 上述 氧化 过程 生成 的 Ｃｒ（ Ⅲ） 可电解再 生为氧 化媒质 Ｃｒ（ Ⅵ） ,在 最佳工艺 条件下 其产率大 于９５ ％ ．     

毕兹多克隆抗体的制备和分析应用

用琥珀酸酐－碳二亚胺法和氯磺化法合成了毕兹（Ｂｚ）的两种人工抗原Ｂｚ＿ＨＳ＿ｐｒｏｔｅｉｎ和Ｂｚ＿ＳＯ２＿ｐｒｏｔｅｉｎ。由Ｂｚ＿ＳＯ２＿ＢＳＡ（牛血清白蛋白）诱导出的抗血清能够用来测定１０－９ｍｏｌ·Ｌ－１的Ｂｚ，工作曲线的线性范围在３×１０－５～３×１０－９ｍｏｌ·Ｌ－１，相对标准偏差为１３６％（ｎ＝６），回收率在９０％～１１５％。     

花生中黄曲霉毒素B1、B2、G1、G2的多功能净化柱-高效薄层色谱分析

建立了一种测定食品中黄曲霉毒素（ ＡＦＴ） Ｂ１ 、Ｂ２ 、Ｇ１ 、Ｇ２ 的多功能净化柱（ ＭＦＣ） 净化, 单相展开的薄层色谱法。 以乙腈－ 水（ 体积比９ ∶１） 提取样品中ＡＦＴ, 经ＭＦＣ 净化浓缩后, 采用ＨＳＧ６０ 薄层板, 以丙酮－ 氯仿（ 体积比９ ∶１） 展开, 薄层扫描仪荧光检测扫描定量。该法用于花生样品的检测,４ 种毒素的分离良好; 线性范围：０ ．０５ ～１ ．０ ｎｇ, 相关系数≥０ ．９９９ １; 检出限均达到０ ．５ ×１０ － ９ ; 相对标准偏差为４ ．６７ ％ ～１０ ．２１ ％ ; 样品加标０．５ ×１０ － ９ ～１０ ×１０ － ９ , 平均回收率为８６ ．５ ％ ～９９ ．０％ 。     

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.