共查询到20条相似文献,搜索用时 62 毫秒
1.
用磺胺甲基异恶唑作基基,大孔硅胶和为基质的高效亲和色谱分离纯化胰凝蛋白酶及胰蛋白酶。20多种蛋白质和酶在该柱上无特异性吸附。 相似文献
2.
3.
本文通过对多组样品的试验测定,建立了一种渔用饲料中8种常用磺胺(磺胺嘧啶、磺胺甲基嘧啶、磺胺二甲基嘧啶、磺胺噻唑、磺胺甲基异噁唑、磺胺多辛、磺胺异噁唑和磺胺喹噁啉)的超高效液相色谱检测法。具体是:样品经2%乙酸浸润,4℃预冷的乙腈提取,碱性氧化铝柱净化,用Symmetry-C18色谱柱(5μm,4.6×150mm),2%乙酸-甲醇梯度洗脱,紫外检测,检测波长270nm。结果表明,8种磺胺的定量底限为2mg/kg,在0.5~20μg/m L内,线性关系良好,R20.99。添加水平10mg/kg时,8种磺胺类药物的平均回收率范围为70%~100%,RSD15。该方法回收率高,简单,准确可靠,可用于渔用饲料中磺胺类药物残留的监测。 相似文献
4.
高效液相色谱-电化学阵列检测器检测10种磺胺药物在鸡肉中的残留 总被引:12,自引:0,他引:12
建立了一步有机溶剂提取、HPLC分离、多孔石墨电极阵列检测器检测10种磺胺类药物在鸡肉中残留量的方法。采用乙腈-氯仿混合液(乙腈:氯仿=10:1)提取,10种磺胺药物的提取收率均大于50%;研究了磺胺类药物在多孔石墨电极上的氧化还原特征,确定检测电势为455,560,630,670和710mV;优化了HPLC分离条件,Hypersil BDS C-18色谱柱,pH5、30mmoL/L磷酸二氢钠、8.5%-37.5%乙腈(V/V)线性梯度洗脱,40min内实现10种磺胺药物的基线分离,鸡肉中提取的杂质不干扰样品分离;方法的检出限(S/N=3)为磺胺二甲异喔唑(SIA)40μg/kg及磺胺(SA)、磺胺嘧啶(SDZ)、磺胺甲基嘧啶(SMR)、磺胺二甲基嘧啶(SMZ)、磺胺吡啶(SPD)、磺胺噻唑(STZ)、磺胺甲噻二唑(SMTZ)、磺胺氯哒嗪(SCP)和磺胺甲基异喔唑(SMX)等分别为20μg/kg,在0.1—2.0mg/L浓度范围内各磺胺类药物与其响应信号呈现良好的线性关系,相关系数(r)均大于0.9978;电极再生方法简单,可实现在线清洗,适用于食用畜禽产品中磺胺类药物残留量的分析。 相似文献
5.
以磺胺异噁唑为模板分子,二甲基丙烯酸乙二醇酯为交联剂,分别用甲基丙烯酸和4-乙烯基吡啶为功能单体,采用牺牲硅胶法合成了磺胺异噁唑分子印迹聚合物;通过静态平衡结合法和Scatchard分析法,系统研究了不同单体对聚合物识别性能和选择性的影响;对比磺胺异噁唑和磺胺二甲嘧啶的结合特性,以4-乙烯基吡啶为功能单体的印迹聚合物具有较好的选择性;Scatchard分析表明,该印迹聚合物在印迹过程中形成了两类不同的结合位点,计算了离解常数分别为2.01×10-4和7.30×10-3mol/L. 相似文献
6.
超高效液相色谱-串联质谱法同时测定化妆品中的22种磺胺类药物 总被引:6,自引:0,他引:6
建立了同时测定化妆品中22种磺胺类药物(磺胺胍、磺胺、磺胺嘧啶、磺胺二甲异嘧啶、磺胺醋酰、磺胺噻唑、磺胺吡啶、磺胺甲基嘧啶、磺胺对甲氧嘧啶、磺胺二甲噁唑、磺胺二甲嘧啶、磺胺甲噻二唑、磺胺甲氧哒嗪、琥珀酰磺胺噻唑、磺胺氯哒嗪、磺胺甲基异噁唑、磺胺间甲氧嘧啶、磺胺邻二甲氧嘧啶、磺胺二甲异噁唑、磺胺间二甲氧嘧啶、磺胺喹噁啉、磺胺硝苯)的超高效液相色谱-串联质谱分析方法。膏霜、水剂、散粉、香波、唇膏等不同类型的化妆品样品经超声提取后,以Waters ACQUITY UPLC BEH C18色谱柱(50 mm×2.1 mm,1.7μm)分离后进行UPLC/MS/MS多反应监测模式下的定性及定量分析。22种磺胺类药物的方法检出限为3.5~14.1μg/kg;在低、中、高的3个添加水平范围内的平均回收率为80.3%~103.6%;日内精密度均小于12%,日间精密度均小于15%。 相似文献
7.
8.
液相色谱-串联质谱同时测定家禽组织中16种磺胺残留 总被引:18,自引:0,他引:18
5g家禽组织样品,用乙腈提取,旋转蒸发器减压蒸干后,用乙腈0.01mol/L乙酸铵溶液溶解(12:88,V/V),用正己烷去除脂肪后,样液用高效液相色谱分离,电喷雾串联四级杆质谱进行检测,外标法定量。本方法研究的16种磺胺(磺胺甲噻二唑、磺胺醋酰、磺胺嘧啶、磺胺氯哒嗪、磺胺甲基异唔唑、磺胺甲基嘧啶、磺胺吡啶、磺胺二甲异嘌唑、磺胺-6-甲氧嘧啶、磺胺邻二甲氧嘧啶、磺胺甲氧哒嗪、磺胺间二甲氧嘧啶、磺胺噻唑、磺胺二甲嘧啶、磺胺甲氧嘧啶、磺胺苯吡唑)的线性范围为0.2—120ng,线性相关系数r〉0.995;在2.5—600μg/kg的4个添加水平范围内的平均回收率为75.4%-97.3%;相对标准偏差为3.48%-14.09%;方法检出限(LOD)为1.0—12.0μg/kg;方法定量限(LOQ)为2.0—24.0μg/kg。 相似文献
9.
一种研究生物大分子与其小分子配基相互作用的毛细管电泳新方法 总被引:3,自引:0,他引:3
建立了一种定量研究大分子与小分子间相互作用的毛细管电泳新方法,即在线微透 析三电极系统亲和毛细管电泳法。本法可测定小分子的自由浓度而不受蛋白质大分子的干 扰。详细介绍了实验装置的制作,探讨了进样机制。作为实例,研究了生理条件下pH7.4, 50mmol/L磷酸介质中,牛血清白蛋白与磺胺甲基异噁唑、L-色氨酸、D-色氨酸的亲和常数的 测定,其值分别为5.8×10~ 4L/mol, 2.3 ×10~4L/mol, 1.77×10~3L/mol。本法较简便,能在生理环 境下测定,样品用量亦少。 相似文献
10.
11.
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%. 相似文献
12.
Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction
Laurent Gavara Thomas Boisse Jean-Pierre Hénichart Adam Daïch Philippe Gautret 《Tetrahedron》2010,66(38):7544-5571
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. 相似文献
13.
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. 相似文献
14.
Rebecca J. Burton Mandy L. CrowtherNeal J. Fazakerley Shaun M. FilleryBarry M. Hayter Jason G. KettleCaroline A. McMillan Paula PerkinsPeter Robins Peter M. SmithEmma J. Williams Gail L. Wrigley 《Tetrahedron letters》2013
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. 相似文献
15.
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. 相似文献
16.
N. A. Nedolya 《Chemistry of Heterocyclic Compounds》2008,44(10):1165-1219
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. 相似文献
17.
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. 相似文献
18.
19.
《Tetrahedron》2014,70(21):3377-3384
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. 相似文献
20.
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. 相似文献