基质固相分散液相色谱-串联质谱法检测禽蛋中的苏丹红

应用基质固相分散技术和液相色谱-串联质谱法(LC-MS/MS)测定了禽蛋中的苏丹红Ⅰ、Ⅱ、Ⅲ、Ⅳ染料.制备样品后装柱,用氯仿-乙腈(体积比为90∶10)混合溶剂洗脱,洗脱液浓缩定容后经ZORBAX SB-C18柱分离,采用电喷雾正离子多反应监控(MRM)模式质谱检测,外标法定量.苏丹红Ⅰ、Ⅱ、Ⅲ、Ⅳ的线性范围分别为0.5～100 ng/g,5.0～100 ng/g,1.0～100 ng/g和2.0～100 ng/g,线性方程的相关系数均大于0.99.样品的添加回收率在87.3%～113%之间,相对标准偏差均小于9.1% .4种苏丹红染料的检测低限分别为0.1,2.0,0.2,0.4 μg/kg,可以满足国内外禽蛋中苏丹红的监控要求.     

液相色谱-串联质谱法测定浓缩胡萝卜汁中8种苏丹类染料

提出了液相色谱-串联质谱法同时测定浓缩胡萝卜汁中苏丹橙G、苏丹红G、苏丹红7B、苏丹黄、苏丹红Ⅰ、苏丹红Ⅱ、苏丹红Ⅲ、苏丹红Ⅳ等8种苏丹类染料含量的方法。样品经正己烷提取,于39℃旋转蒸发至近干,氮气吹干后用1mL乙腈和0.1%(体积分数,下同)甲酸(1+1)混合液溶解。采用Hypersil GOLD色谱柱(50mm×2.1mm,1.9μm)为分离柱和以不同比例的0.1%甲酸和甲醇混合液为流动相作梯度淋洗,采用多反应监测正离子模式监测。8种苏丹类染料的质量浓度均在30～100μg.L-1范围内呈线性,测定下限(10S/N)在5～30μg.kg-1之间。在3个浓度水平下做加标回收试验,回收率在72.0%～96.0%之间,测定值的相对标准偏差(n=6)在6.2%～9.6%之间。     

高效液相色谱化学发光检测法测定食品中苏丹红Ⅰ

基于碱性条件下,苏丹红Ⅰ对鲁米诺-KIO4发光体系的增敏作用,建立了高效液相色谱化学发光测定苏丹红Ⅰ的新方法。方法采用Phenomenex C18色谱柱(250×4.6mm,5μm),以乙腈∶甲醇∶水=5∶4∶1(V/V/V)为流动相,在0.001～0.50μg/mL范围内,苏丹红Ⅰ浓度与发光强度呈良好的线性关系,相关系数为0.9996,检出限为5ng/kg,相对标准偏差为1.45%(c=0.01μg/mL,n=6),加标回收率为95.0%～104.0%。该法灵敏、准确,用于实际样品中苏丹红Ⅰ的测定,结果令人满意。     

分散固相萃取/高效液相色谱法测定鸡蛋中对位红与苏丹红染料残留

建立了一种分散固相萃取结合高效液相色谱法测定鸡蛋样品中对位红及苏丹红Ⅰ^Ⅳ染料残留的分析方法。样品经正己烷超声提取,二醇基（Diol）硅胶吸附富集,乙腈洗脱后在Phenomenex Luna C₁₈色谱柱（50 mm×2.0 mm,5μm）上以乙腈-水为流动相梯度洗脱,在500 nm波长处检测,外标法定量。5种染料在0.1¹0.0 mg·L^-1范围具有良好的线性,相关系数均大于0.999,在低、中、高3个加标水平的平均回收率为81.2%⁹4.2%,相对标准偏差为3.4%⁵.3%,检出限为0.018⁰.030 mg·kg^-1,定量下限为0.06⁰.10 mg·kg^-1。建立的方法准确快速,可用于鸡蛋中对位红和苏丹红类染料残留的快速检测。     

凝胶净化/超高效液相色谱电喷雾质谱法检测调味油中11种禁用偶氮染料及罗丹明B

建立了凝胶渗透色谱(GPC)净化/超高效液相色谱-电喷雾串联四极杆质谱(UPLC-MS/MS)同时检测调味油中11种脂溶性偶氮类工业染料(苏丹红Ⅰ、苏丹红Ⅱ、苏丹红Ⅲ、苏丹红Ⅳ、苏丹红7B、苏丹红G、苏丹黄、苏丹橙G、苏丹蓝Ⅱ、甲苯胺红、对位红)和罗丹明B的分析方法。样品经乙酸乙酯-环己烷(1∶1)提取,采用凝胶渗透色谱(GPC)去除大分子油脂、天然色素等干扰物质;以乙腈-0.1%甲酸为流动相,目标化合物在梯度洗脱条件下经C18柱分离后采用多离子反应监测(MRM)正离子模式进行检测。结果表明:调味油中12种工业染料的线性范围为1～50μg/L,定量下限(LOQ)为0.2～2.5μg/kg,在5、20、40μg/L 3个加标水平下的回收率为54%～125%,相对标准偏差为2.5%～17.2%。随机抽取市售35份样品进行检测,其中两份样品检出罗丹明B。该方法操作简便、灵敏度高,实现了11种禁用偶氮染料和罗丹明B的同时提取和净化,适合于调味油中非法添加脂溶性偶氮工业染料和罗丹明B的筛查与确证。     

应用凝胶色谱与固相萃取净化技术检测食品中6种禁用染料

建立了固相萃取净化和凝胶色谱净化两种前处理方法,应用高效液相色谱串联质谱法同时测定了食品中苏丹红Ⅰ,Ⅱ,Ⅲ和Ⅳ,对位红、罗丹明B 6种禁用染料。根据不同的净化技术,分别选用甲醇和乙酸乙酯-环己烷(1:1,V:V)作为提取溶剂,利用C8色谱柱(1.8μm,3.0×100 mm)分离,电喷雾串联四极杆质谱ESI源,在多反应监测模式下对6种禁用染料进行检测。用相萃取净化方法苏丹红Ⅰ,Ⅱ,Ⅲ,Ⅳ和对位红的检出限为0.005 mg/kg,罗丹明B的检出限为0.002 mg/kg;疑胶色谱净化方法苏丹红Ⅰ,Ⅱ,Ⅲ,Ⅳ和对位红的检出限为0.010 mg/kg,罗丹明B的检出限为0.005 mg/kg。通过比较两种净化方法在检测复杂基质中的实际应用,固相萃取净化法在去除大分子物质、天然色素方面的效果好于凝胶色谱净化法。     

蛋品中苏丹红残留的液相色谱串联质谱测定法研究

采用液相色谱-串联质谱法（LC-MS/MS）测定了蛋品中苏丹红I、II、III、Ⅳ号染料的残留。制样后,装柱,应用基质固相分散技术,用氯仿、乙腈混合溶液（体积比为90：10）淋洗,浓缩定容后经ZORBAX SB-C18柱分离,采用电喷雾正离子,多反应监控（MRM）模式检测。外标曲线定量,苏丹红I、II、III、Ⅳ的线性范围分别为0.5～100ng/g,5.0～100ng/g,1.0～100ng/g和2.0～100ng/g,线性方程的相关系数都大于0.99,添加样品回收率在87.3～113％之间,相对标准偏差均小于9.1％。针对四种苏丹红染料,该方法的检测低限分别可达0.1μg/kg,2.0μg/kg,0.2μg/kg,0.4μg/kg,可以满足国内外蛋品中苏丹红监控要求。     

蛋品中苏丹红残留的液相色谱串联质谱测定法研究

采用液相色谱-串联质谱法（LC-MS/MS）测定了蛋品中苏丹红I、II、III、Ⅳ号染料的残留。制样后,装柱,应用基质固相分散技术,用氯仿、乙腈混合溶液（体积比为90：10）淋洗,浓缩定容后经ZORBAX SB-C18柱分离,采用电喷雾正离子,多反应监控（MRM）模式检测。外标曲线定量,苏丹红I、II、III、Ⅳ的线性范围分别为0.5～100ng/g,5.0～100ng/g,1.0～100ng/g和2.0～100ng/g,线性方程的相关系数都大于0.99,添加样品回收率在87.3～113％之间,相对标准偏差均小于9.1％。针对四种苏丹红染料,该方法的检测低限分别可达0.1μg/kg,2.0μg/kg,0.2μg/kg,0.4μg/kg,可以满足国内外蛋品中苏丹红监控要求。     

酶联免疫吸附分析法测定食品中的苏丹红Ⅰ号

本研究建立了测定食品中苏丹红Ⅰ号含量的间接竞争酶联免疫分析法。首先对苏丹红Ⅰ号分子作了的修饰,再与载体蛋白交联制得免疫原和包被抗原,经动物免疫制得抗苏丹红Ⅰ号的抗体。在包被抗原为100μg/L,抗体为1:100,000倍稀释,标记二抗为1:15000倍稀释的优化条件下,测得检出限为0.12μg/L,IC50值(标准曲线中吸光度抑制至最大吸光度值的50%时所对应的待测物浓度)为0.74μg/L。苏丹红Ⅰ号在番茄酱和辣椒面中的回收率分别为106%和110%。样品仅需甲醇萃取再用缓冲液简单稀释就可以直接进行ELISA测定。     

固相萃取/超高效液相色谱-串联质谱法同时测定禽蛋中4种苏丹红染料残留量

建立了禽蛋及其制品中4种苏丹红染料(苏丹红Ⅰ,Ⅱ,Ⅲ和Ⅳ)残留量的固相萃取/超高效液相色谱-串联质谱(UPLC-MS/MS)测定方法。样品经正己烷超声提取,上清液经苏丹红专用SPE柱净化,采用Waters CORTECSTMUPLCC18(2.1 mm×100 mm,1.7μm)柱以5 mmol/L乙酸铵溶液-0.2%甲酸和乙腈为流动相梯度洗脱分离,电喷雾电离(ESI)正离子多反应监测模式(MRM)进行测定,内标法定量。结果表明,苏丹红Ⅰ~Ⅳ在0.5~20μg/L范围内线性关系良好,相关系数均大于0.999;在低、中、高3个加标水平的平均回收率为80.0%~104.2%,相对标准偏差为4.2%~10.9%。方法的检出限(LOD)为0.26~0.35μg/kg,定量下限(LOQ)为0.9~1.2μg/kg。该方法操作简便、准确、快速、灵敏,可用于禽蛋和蛋制品中苏丹红染料的检测分析。     

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.