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1.
冯晓双  陈炜 《分析化学》1995,23(4):453-455
通过吸附丝富集样品中的游离烃,热解析后直接进行色谱-质谱分析,该法适用于土、岩石、水及油气样品,操作简便,灵敏度高,可检测至C16的烃类,是油敢化探中行之有效的一种新方法。  相似文献   

2.
硬膏剂中甲苯残留的吹扫—捕集GC—MS测定方法   总被引:1,自引:0,他引:1  
建立了一种吹扫-捕集进样与气相色谱-质谱联用、选择离子监测的方式,测定样品中甲苯溶剂残留的方法。该法操作方便、简单。方法相对标准偏差为375%,平均回收率为957%。适用于医药、食品包装等行业甲苯残留的检测。  相似文献   

3.
头发中单乙酰吗啡和吗啡检测的研究   总被引:3,自引:0,他引:3  
建立了用GC-MS技术检测人头发中毒品海洛因的主要代谢产物6-单乙酰吗啡和吗啡的方法。以乙基吗啡为内标,样品酸水解后用混合有机溶剂提取。提取物经N-甲基-N-三甲基硅基三氟乙酰胺(MSTFA)衍生化,采用GC-MS定性定量分析。该法已用于确认经常性滥用海洛因的实际检案分析  相似文献   

4.
用一种甘氨酸N-端保护试剂和1,5-苯并硫氮杂卓反应,合成了51,5-苯并硫氮杂卓-α-氨基-β-内酰胺衍生物,其结构经元素分析、^1H NMR,MS和IR确证,用X射线衍射法确定了产物的立体结构,结果表明,该反应具有立体专一性,四元环上的两个取代基位于环的同侧,为顺式结构,产物分子中的七元环为稳定的类椅式构象。  相似文献   

5.
吖啶橙(AO)-藏红T(ST)荧光探针测定DNA的研究   总被引:4,自引:1,他引:3  
简述了以荧光能量转移本系测定DNA方法的发展过程,同时对吖啶(AO)-藏红T(ST)荧光探针测定DNA的条件进行分析,证明了该法灵敏度高、线性范围宽、检出限低、选择性好、抗干扰能力强,该法为微曦DNA测定分析工作提供了一个新的途径。  相似文献   

6.
L-半胱氨酸的停流流动注射动力学快速测定法   总被引:1,自引:0,他引:1  
利用L-半胱氨酸可还原Fe(3+),使之生成Fe(2+)-邻菲 啉有色络合物的反应,建立了L-半胱氨酸的停流流动注射动力学分光光度测定的新方法。该法简便、灵敏、快速、准确、选择性高,检测限为16mg/L,分析频率达30样/h。取L-半胱氨酸浓度为160mg/L时,测量的相对标准偏差为0.55%(n=6)。实际样品加标回收率达98.7%。  相似文献   

7.
(9Z,12Z,15Z)-十八碳三烯醛是美国白蛾信息素的主要成效成分之一,在其合成的过程中,采用气相色谱监测分离提纯效果;提纯的样品成分在化学方法、IR、^1H NMR波谱分析基础上用气相色谱-质谱鉴定为该化合物,并用气相色谱的面积归一化法测得其含量大于99%;该法简单、准确可靠、无需标样。  相似文献   

8.
6种口服降糖药的液相色谱-质谱分析   总被引:8,自引:4,他引:8  
为鉴定中药制剂里非法掺入的口服降糖药,建立了6种口服降糖药的液相色谱-质谱分析法,总结了该类药物分子的质谱裂解规律,经色谱分离后,以多级质谱方式,对中药制剂的有效溶提取物进行检测。通过对非法掺有口服降糖药苯乙双胍;另外,通过谱行为推测提取中含有另一口服降糖药氯磺丙脲。该法专属性强,灵敏度高,可作为分析检测非法中药制剂的有效手段。  相似文献   

9.
ICP-AES法测定氯化钾中的钾含量   总被引:1,自引:0,他引:1  
以K766.490NM为分析谱线,研究了电感耦合等离子体发射光谱(ICP-AES)法测定工业和农业用氯化钾中钾含量的方法。经实际样品测定,RSD为0.3215%。t检验结果证明,该方法与四苯硼钾重量法之间无显著性差异。该方法简便、快速,测定结果准确、可靠。  相似文献   

10.
气相色谱法检测工业用乙二醇纯度及杂质   总被引:1,自引:0,他引:1  
范晨亮  张育红  王川  彭振磊  高枝荣 《色谱》2019,37(1):116-120
以Rtx-624色谱柱(30 m×0.32 mm×1.8 μm)为分析柱进行分析,采用校正面积归一化法,建立了检测工业用乙二醇纯度及其中有机杂质的气相色谱分析法。该法可检测传统乙烯法制得的乙二醇中固有杂质二乙二醇、三乙二醇和1,3-二氧杂烷-2-甲醇,同时也适用于检测草酸酯加氢法制得的乙二醇中的新杂质(1,2-丁二醇、1,4-丁二醇、1,2-己二醇、碳酸乙烯酯等)。结果表明,该法具有良好的重复性和较高的检测灵敏度,检出限最低可达0.0002%(质量分数),回收率在91.2%~105.4%之间。该法在乙二醇生产控制、产品检测、市场贸易等过程中具有良好的应用前景。  相似文献   

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.
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   

13.
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   

14.
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   

15.
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   

16.
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   

17.
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   

18.
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.  相似文献   

19.
Zhanhui Yang  Shiyi Yang  Jiaxi Xu 《Tetrahedron》2017,73(23):3240-3248
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   

20.
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.  相似文献   

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