首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 46 毫秒
1.
HPLC法测定中成药制剂中10-羟基-2-癸烯酸的含量   总被引:6,自引:0,他引:6  
杨江丰  陈理 《色谱》1998,16(2):178-179
采用SpherisorbC18柱,以甲醇∶水∶磷酸(45∶65∶0.5)为流动相,以UV210nm为检测波长,测定中成药制剂中10-羟基-2-癸烯酸(10-HDA)的含量,10-HDA浓度在0.006~0.030g/L范围内线性关系良好(r=0.9999,n=5),检测限为0.2mg/L(S/N=3∶1)。方法具有定量准确、快速及主峰和杂质分离度高等特点。  相似文献   

2.
谢航  张声华 《色谱》1997,15(1):54-56
干枸杞经粉碎、匀浆、离心后,通过阳离子交换柱脱去样品中其它氨基酸,再通过Zorbax-C8柱进行柱前衍生分离。衍生剂:A.4%OPA甲醇溶液;B.尿素∶磷酸钠盐缓冲液(pH6.8)=1∶3(W/V)。流动相:甲醇∶0.01mol/L乙酸钠溶液(pH6.8)=35∶65(V/V)。紫外检测波长330nm。牛磺酸浓度在0.1~1.0mmol/L范围内可被定量测定。回收率可达100.31%±1.98%,变异系数(CV)为1.94%。  相似文献   

3.
反相离子对色谱法测定化妆品中溴硝丙醇等11种防腐剂   总被引:5,自引:0,他引:5  
胡俊明  王骏 《色谱》1999,17(5):495-497
采用反相离子对色谱法测定化妆品中溴硝丙醇等11种防腐剂,以ZorbaxC8为固定相,V(0.05mol/L磷酸二氢钠)∶V(甲醇)∶V(乙腈)=50∶35∶15的溶液为流动相,添加氯化十六烷三甲胺(浓度为2mmol/L),用磷酸调pH值为35,检测波长为254nm。样品用甲醇超声提取,回收率为85%~107%(n=6),相对标准偏差为22%~7.5%。  相似文献   

4.
5-磺酸钠间苯二甲酸二甲酯的高效液相色谱法分析   总被引:2,自引:1,他引:1  
提出了用离子对反相高效液相色谱分析5-磺酸钠间苯二甲酸二甲酯的方法,色谱柱为HypersilBDSC18,5μm,250mm×4.6mm,流动相为V(甲醇)∶V(水)=60∶40(甲醇中含四丁基磷酸二氢铵10mmol/L),柱温为30℃,流速为0.8mL/min,进样体积为20μL,检测波长为220nm。用外标法进行了定量,相对标准偏差和回收率分别为0.26%和98.1%~99.6%。  相似文献   

5.
反相高效液相色谱法测定雷公藤提取物中雷公藤甲素含量   总被引:12,自引:0,他引:12  
李克  袁倚盛  戴晓莉  乔小云 《色谱》1998,16(4):356-357
应用反相高效液相色谱法检测了雷公藤提取物中雷公藤甲素的含量。样品经洗脱提取后,以C18化学键合硅胶为固定相,乙腈-水(40∶60,V/V)为流动相,用210nm波长定量检测。测定结果表明,雷公藤甲素浓度在0.25~4.00mg/L范围内线性良好,最低进样检测浓度为0.1mg/L。批内(n=5)及批间(n=5)测定相对标准偏差分别为1.9%~6.5%和2.7%~7.8%,回收率为89.8%~92.0%。  相似文献   

6.
钍钼杂多酸-丁基罗丹明B测定岩矿中痕量钍   总被引:2,自引:0,他引:2  
本文报道了一个灵敏度高、选择性好的测定痕量钍的新光度分析法。在聚乙烯醇(PVA)存在下,钍钼杂多酸和丁基罗丹明B(BRB)形成离子缔合物,其适宜条件为cHClO4=1.3mol/L,cMoO42-=6.8×10-4mol/L,cBRB=2.7×10-5mol/L,PVA0.08%。络合物的最大吸收波长为570nm,服从比耳定律范围0~0.8mg/25LTh,表观摩尔吸光度ε为3.63×106L·mol-1·cm-1,测定极限1.8μg/L(n=12),对0.02mg/LTh分析11次的相对标准偏差为2.9%,络合物的摩尔组成Th∶Mo∶BRB=1∶12∶7。大多数常见元素、100倍Ce(Ⅲ)、40倍U(Ⅵ)和20倍P(Ⅴ)不干扰钍的测定。本法已用于地质标样中钍的测定,结果满意。  相似文献   

7.
肿瘤细胞中长春新碱的高效液相色谱法测定   总被引:10,自引:0,他引:10  
黎丹戎  涂文升  李力  唐东平  黄薇 《色谱》1998,16(1):50-52
长春新碱(VCR)为重要和常用抗肿瘤药物之一。肿瘤细胞耐药性是导致化疗失败的主要原因。为了筛选耐药细胞的逆转剂,建立了测定肿瘤细胞内VCR浓度的高效液相色谱法,色谱条件为:Zorbax-ODS反相柱25cm×4.6mmi.d.,流动相:0.02mol/LK2HPO4(pH6.6)∶CH3OH(20∶80,V/V),流速:1.0mL/min,检测波长:267nm。方法简单、快速、选择性好,在10~200mg/L范围内VCR浓度-峰高呈良好的线性关系(r=0.9998),仪器灵敏度为4ng。  相似文献   

8.
以甲醇-水(95:5,V/V)为流动相,用ODS柱以高效液相色谱法测定非诺贝特含量。紫外检测波长为286nm。非诺贝特在浓度为0.04-0.20g/L间线线性关系良好。重复进样RSD=0.14%,最低检出浓度为0.10mg/L,平均回收率为99.66%。  相似文献   

9.
高效液相色谱法测定人血清中头孢克罗   总被引:1,自引:0,他引:1  
建立了测定人血清中头孢克罗的高效液相色谱法。分析柱为Shim-packCLC-ODS(5μm),6.0mm×150mm;流动相为磷酸盐缓冲液(pH5.8)∶乙腈=87.5∶12.5,流速为1.2mL/min;紫外检测波长为254nm。血清中头孢克罗浓度在0.125~24mg/L范围内,峰高与浓度呈良好的线性关系,回归方程为H=-3.200+92.29C(n=9,r=0.9999),日内、日间变异系数分别为4.1%和5.8%,平均回收率为99.3%。  相似文献   

10.
山药中尿囊素的高效液相色谱分析方法研究   总被引:8,自引:1,他引:8  
周心如  曹京宜 《色谱》1996,14(2):129-131
建立了山药中尿囊素的高效液相色谱分析方法。样品用甲醇-水(90:10,V/V)提取,在氨基柱上进行高效液相色谱分析,紫外检测波长224nm,流动相为甲醇-水(80:20,V/V),相对标准偏差为2.0%(n=5),尿囊素的回收率为98.8%(n=4)。  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.
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.
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.
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.
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   

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   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号