HPLC同时测定牛蛙中的己烯雌酚、呋喃唑酮、磺胺类药物残留量

建立牛蛙中己烯雌酚、呋喃唑酮、磺胺甲氧嘧啶、磺胺二甲嘧啶、磺胺间甲嘧啶、磺胺甲恶唑、磺胺喹恶啉残留量同时测定的高效液相色谱法。研究碱性氧化铝活性对磺胺,己烯雌酚、呋喃唑酮净化效果的影响。样品以乙腈提取,正己烷脱脂,碱性氧化铝净化,Hypersil ODS C18(4.6 mm i.d.×250 mm,5μm)进行分离。回收率在82.3%~95.3%,相对标准偏差为3.3%~5.7%,己烯雌酚、呋喃唑酮和磺胺的检出限分别为0.5、0.1和0.2 ng。     

超高效液相色谱-串联质谱测定污泥中氯霉素、磺胺类、喹诺酮类、四环素类与大环内酯类抗生素

建立了测定城市污水处理厂污泥中50种抗生素(氯霉素、磺胺、喹诺酮、四环素和大环内酯类)的超高效液相色谱-串联质谱(UPLC-MS/MS)分析方法。污泥样品经乙腈-水溶液超声萃取,高速冷冻离心后,提取液经过HLB柱富集和NH2柱净化;ACQUITY UPLC BEH C18柱用作色谱分离,以0.1%甲酸水溶液-甲醇(ESI+)和乙腈-水(ESI-)为流动相进行梯度洗脱;多反应监测(MRM)模式进行检测;目标药物使用基质外标法定量。50种目标药物的线性范围为0.50～400μg/L,相关系数均大于0.99。方法定量下限为0.10～5.00μg/kg,3个加标水平下的回收率为40%～111%,相对标准偏差为2.9%～27.1%。应用此方法对北京某污水处理厂活性污泥和剩余污泥进行检测,共检出14种药物,包括磺胺嘧啶、磺胺吡啶、磺胺甲唑、吡哌酸、氧氟沙星、依诺沙星、培氟沙星、诺氟沙星、环丙沙星、恩诺沙星、洛美沙星、斯帕沙星、土霉素和阿奇霉素,其浓度为1.2～442.5μg/kg。该方法简便快速、灵敏可靠,适用于污泥中多种抗生素药物残留的同时测定。     

猪肉中四种磺胺类药物残留的快速HPLC测定法

本文研究了一种快速、方便的测定猪肉中四种磺胺类药物;磺胺嘧啶(SDZ)、磺胺甲基噻啶(SMR)、磺胺二甲嘧啶(SMZ)、磺胺噬啶(STH)的高效液相色谱法。采用乙腈、氯仿提取样品,液液分配净化,再以RP-HPLC分离,紫外检测器254nm波长下检测定量、空白样品添加0.05～0.2mg/kg四种磺胺药物,回收率在74～85%的范围内;变异系数为2～7%;可检测出样品中低至5μg/kg的磺胺药物残留。     

超高效液相色谱法检测化妆品中的12种磺胺抗生素

建立了采用超高效液相色谱(UPLC)-二极管阵列检测器（PDA）测定化妆品中12种常见的磺胺抗生素(磺胺、磺胺间甲氧嘧啶、磺胺醋酰、磺胺甲基异唑、磺胺嘧啶、磺胺二甲异唑、磺胺噻唑、磺胺二甲氧嘧啶、磺胺甲基嘧啶、磺胺喹啉、磺胺二甲嘧啶、磺胺硝苯)的方法。采用Acquity UPLCTM BEHC C18 色谱柱(50 mm×2.1 mm, 1.7 μm),流动相为乙腈/0.1%的甲酸水溶液,梯度洗脱。样品经提取、反萃取后,用UPLC-PDA进行分析检测,结合保留时间和紫外光谱进行定性分析,定量检测波长268 nm。12种磺胺的检出限(S/N=3)均为1 μg/g,定量下限(S/N=10)为2～3 μg/g,在1～25 mg/L(磺胺硝苯为0.5～12.5 mg/L)范围内,峰面积和质量浓度的线性关系良好(r>0.9997)。添加水平为40, 8 μg(磺胺硝苯为20, 4 μg)时,12种磺胺的平均回收率分别为86.8%～98.1%和80.1%～96.9%,相对标准偏差小于10%(n=6)。结果表明该方法简单,分离效果好,速度快,能够满足检测化妆品中12种常见的磺胺抗生素的需要。     

基质固相分散-超快速液相色谱法测定牛肉中磺胺类兽药

采用基质固相分散-超快速液相色谱测定了牛肉组织中磺胺噻唑、磺胺甲基嘧啶、磺胺甲基异恶唑和磺胺间二甲氧嘧啶。基质固相分散萃取的最佳条件为:硅藻土为分散剂,6 mL甲醇为洗脱剂,样品与分散剂的质量比为1∶4。方法的检出限为4.39～7.82 ng/g,定量限为14.62～26.08 ng/g,4种磺胺化合物回收率为71.73%～113.13%,测定的相对标准偏差为1.9%～12.7%。     

高效液相色谱-串联质谱测定熟肉制品中磺胺嘧啶和氯霉素药物残留

建立了一种应用高效液相色谱-串联质谱法(HPLC-MS/MS)同时检测熟肉制品中磺胺嘧啶和氯霉素药物残留的方法。样品经乙腈多次提取,正己烷去脂,采用乙酸铵-乙腈体系为流动相,梯度洗脱分离,电喷雾多反应监测模式同时质谱检测。磺胺嘧啶和氯霉素分别在5～500μg/kg和0.1～10μg/kg的线性范围内线性相关系数(R2)均大于0.999,其检出限分别为5μg/kg和0.1μg/kg。磺胺嘧啶和氯霉素在熟肉制品中的回收率分别为78.6%～94.4%和68.7%～86.3%。     

高效液相色谱法同时测定动物源性食品中5种磺胺及3种四环素族抗生素残留

建立了动物源性食品中5种常用磺胺(磺胺甲噁唑、磺胺2甲氧嘧啶、磺胺二甲基嘧啶、磺胺-6甲氧嘧啶、磺胺喹噁啉)及3种四环素族(土霉素、金霉素、四环素)抗生素残留的高效液相色谱同时测定方法.样品经提取,固相萃取净化,浓缩后进行HPLC分离,结合保留时间及二极管阵列检测器(PDA)光谱分析信息定性.添加水平为20、50、100μg/kg时5种磺胺及3种四环素族的平均回收率范围为70%~92%,变异系数小于15%.结果表明,该法简单、快速、灵敏,适用于动物源性食品中多磺胺组份及四环素族组份残留的同时测定.     

规模化养殖场废水中抗生素种类及残留特征研究

2010年调查了海南省6家规模化养猪场抗生素使用品种及来源,并采集养殖废水样品,用高效液相色谱紫外检测器检测了样品中4种四环素(四环素、土霉素、金霉素和强力霉素)和8种磺胺类药物(磺胺嘧啶、磺胺甲噻唑、磺胺噻唑、磺胺二甲基嘧啶、磺胺氯哒嗪、磺胺邻二甲氧嘧啶、磺胺间二甲氧嘧啶和磺胺喹恶啉)的残留浓度水平。结果显示,6家养殖场废水中土霉素、四环素和磺胺嘧啶的检出率及检出浓度较高,其中土霉素检出率为100%,最高浓度为71.75μg/L;四环素检出率为63%,最高检出浓度为24.83μg/L;磺胺嘧啶检出率为83%,最高检出浓度为17.69μg/L。4种四环素类检出总量变化范围为18.25～99.64μg/L,8种磺胺类检出总量变化范围为3.45～24.49μg/L;从养殖规模上看,小规模养殖场抗生素类检出品种较多,检出浓度也较高。     

凝胶渗透色谱净化-高效液相色谱法测定鱼肉中的5种激素类药物残留

建立了凝胶渗透色谱净化-高效液相色谱法测定鱼肉中己烯雌酚、雌二醇、炔雌醇、炔诺酮、炔诺孕酮5种激素类药物残留的方法。样品用乙酸乙酯-甲醇(8:2, v/v)溶液提取,提取液经Pharmadex LH-20凝胶柱(450 mm×15 mm)净化,并用甲醇-乙酸乙酯-乙酸(800:200:2, v/v/v)溶液洗脱。采用Agilent TC-C18柱(250 mm×4.6 mm, 5 μm)分离净化后的样品,用乙腈-水(45:55, v/v)溶液洗脱,流速为1.2 mL/min,双检测波长为245 nm和222 nm。5种激素类药物在0.05～2.5 mg/L范围内有良好的线性关系(r ＞0.999),检出限为10～24 μg/kg,平均加标回收率为60.1%～89.0%,相对标准偏差为2.0%～7.4%。该方法快速、简单,可应用于鱼肉中激素类药物残留量的检测。     

胶体金免疫层析法对组织样品中磺胺甲噁唑残留的快速检测

研究了用于快速检测组织样品中磺胺甲噁唑残留的胶体金免疫层析检测试剂.采用免疫竞争法,将抗磺胺甲噁唑多克隆抗体-胶体金复合物包被在胶体金结合垫上,同时将人工合成的磺胺甲噁唑抗原包被在硝酸纤维素薄膜表面作为检测线(T线),将抗磺胺甲噁唑多克隆抗体的羊抗兔二抗包被在硝酸纤维素薄膜表面作为质控线(C线).T线的人工抗原与待测样品中的磺胺甲噁唑竞争结合胶体金标记的磺胺甲噁唑多克隆抗体,通过T线与C线的显色对比读出结果.采用该检测试剂检测组织试样时,定量下限可达20 μg/L,整个检测过程只需3 ～5 min,且与磺胺嘧啶、磺胺二甲基嘧啶、盐酸克伦特罗、四环素、青霉素、链霉素无交叉反应.检测试剂具有较高的灵敏度及特异性,操作便捷,稳定可靠,可作为组织中磺胺甲噁唑残留现场监控的有效筛检手段.     

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.