高效液相色谱柱后衍生测定鸡组织中甲基盐霉素残留量

建立了鸡组织中甲基盐霉素的高效液相色谱柱后衍生化分析方法.样品经异辛烷提取,离心后上层有机相过硅胶固相萃取小柱,洗脱液浓缩后用V(甲醇)∶ V(水)=90∶ 10混合液溶解.采用Inertsil ODS-3 C18柱,以V(甲醇): V(乙酸)∶ V(水)=94∶ 3∶ 3为流动相,香草醛为衍生剂进行高效液相色谱柱后衍生分析,520 nm检测,外标法定量.方法检出限为6 μg/kg; 定量限为20 μg/kg; 添加浓度在20～1800 μg/kg范围内,平均添加回收率为76.4%～93.1%; 批内相对标准偏差(RSD)在2.6%～8.9%之间; 批间相对标准偏差(RSD)在4.7%～9.7%之间.样品浓度在0.07～10.0 mg/L范围内与峰面积呈良好的线性关系,r>0.9993.     

高效液相色谱法测定人血浆及尿液中头孢呋辛和舒巴坦

建立反相HPLC-UV法同时测定人血浆及尿中头孢呋辛(CXM)和舒巴坦(SUL)的方法.采用Welch Materials XB-C18分析柱(150 mm×4.6 mm,5 μm ) ,流动相为乙腈-0.01 mol/L KH2PO4 (血浆测定15∶ 85(V/V),尿样测定10∶ 90(V/V),含0.04%三乙胺,以H3PO4调节至pH 3.2),流速1.0 mL/min,紫外检测波长SUL为220 nm、CXM及内标咖啡酸为274 nm.血浆样品在酸性条件下用乙醚提取浓集后进样,以内标法进行定量分析.尿样稀释后直接进样,以外标法进行定量分析.血浆测定中SUL和CXM浓度分别在0.25～200 mg/L和0.5～400 mg/L范围内线性良好; 萃取回收率分别为75.6%～88.1%和68.6%～77.4%; 批内与批间RSD均小于9%,方法回收率分别为94.6%～113.6%和91.9%～101.8%.尿样中SUL和CXM浓度分别在5～5120 mg/L和10～10240 mg/L范围内线性良好; 批内与批间RSD均小于3%; 方法回收率分别为92.9%～111.1%和98.0%～105.3%.本方法快速简便, 灵敏准确,可用于同时测定血浆及尿中SUL和CXM浓度,亦可用于药代动力学、生物利用度研究.     

反相高效液相色谱法测定犬血清及组织中的维拉帕米

建立了动物血清、肝组织中维拉帕米(verapamil,VRPM)药物浓度的测定方法。 应用反相高效液相色谱法,以安定为内标,采用峰高内标法计算结果。流动相为醋酸盐缓冲液-甲醇-三乙胺(体积比为40∶60∶1)混合溶液,流速1.0 mL/min;检测波长228 nm。 VRPM在犬血清和肝组织中最低检测限分别为50 μg/L和50 ng/g。犬血清和肝组织匀浆中的VRPM质量浓度为0.1～10.0 mg/L及0.25～10.0 μg/g时,该浓度与响应值线性关系良好(r＞0.999)。犬血清和肝组织匀浆中的     

柱前衍生化高效液相色谱测定血清中红霉胺

建立了人血清中地红霉素活性代谢物红霉胺的高效液相色谱荧光检测方法.用甲基叔丁基醚萃取血清中红霉胺,用NBD-Cl衍生化后于反相C18柱上进行分离测定.流动相为V(0.01 mol/L 磷酸盐缓冲液,pH 6.0)∶ V(乙腈)=80∶ 20混合液,流速为1.0 mL/min,地洛他定为内标,标准曲线的线性范围为0.010～1.245 mg/L,日内和日间相对标准偏差均小于9%.最低定量限为10 μg/L.应用本方法对受试者给予地红霉素后血清中的红霉胺浓度进行了测定.     

气相色谱法测定溴己新血药浓度及药代动力学研究

 建立了人血浆中溴己新的气相色谱 电子捕获测定法 ,对溴己新胶囊在健康人体内的药代动力学进行了研究。色谱柱为 5 %SE 30 (2m× 3mmi.d .)硅烷化玻璃柱。 5 氯 2 氨基二苯甲酮为内标 ,血浆样品加入磷酸盐缓冲液 (pH 6 0 )后用正己烷 二氯甲烷 (体积比为 9∶1)提取。线性范围为 1 0 μg/L～ 5 0 0 μg/L ,r =0 9994。人血浆中最小检测质量浓度为 0 5 μg/L。方法重现性好 ,日内、日间RSD分别小于 4 5 6 %和 7 11% ,平均回收率 97 5 %。 8名健康志愿者口服 8mg溴己新胶囊后 ,其体内代谢过程符合一房室模型。     

气相色谱法测定溴己新血药浓度及药代动力学研究

建立了人血浆中溴己新的气相色谱 电子捕获测定法 ,对溴己新胶囊在健康人体内的药代动力学进行了研究。色谱柱为 5 %SE 30 (2m× 3mmi.d .)硅烷化玻璃柱。 5 氯 2 氨基二苯甲酮为内标 ,血浆样品加入磷酸盐缓冲液 (pH 6 0 )后用正己烷 二氯甲烷 (体积比为 9∶1)提取。线性范围为 1 0 μg/L～ 5 0 0 μg/L ,r =0 9994。人血浆中最小检测质量浓度为 0 5 μg/L。方法重现性好 ,日内、日间RSD分别小于 4 5 6 %和 7 11% ,平均回收率 97 5 %。 8名健康志愿者口服 8mg溴己新胶囊后 ,其体内代谢过程符合一房室模型。方法可用于体内血药浓度测定 ,简单、快速 ,灵敏度高 ,数据准确可靠     

柱切换-荧光检测反相高效液相色谱法测定血浆中特布他林浓度

采用柱切换技术 荧光检测反相高效液相色谱法测定血浆中特布他林 (TB)浓度。使用LunaC8( 2 )和KromasilC18为分析柱 ( 1 5 0mm× 4.6mm ,5 μm)和预处理柱 ( 2 5mm× 4.6mm ,5 μm) ,流动相分别为pH 3 0 ,0 .0 3 3mol/L磷酸盐缓冲液∶甲醇∶乙腈 ( 92∶7∶1 )和水∶甲醇∶乙腈 ( 97∶2∶1 ) ,流速均为 1 .0ml/L。血浆样品经乙腈沉淀蛋白后进样 ,切换时间为 3 .2～ 4.2min。荧光检测 ,λex为 2 80nm ,λem为 3 0 9nm。以沙丁胺醇作内标 ,按内标法定量。标准曲线线性范围为 0 .8～ 3 2 μg/L ;最低定量限为 0 .8μg/L;TB和内标的保留时间分别为 8.7和 9.3min;日内RSD小于 4% ,日间RSD小于 9% ,方法回收率在 93 %～ 1 1 2 %。     

高效液相色谱-串联质谱法测定猪肉中泰拉霉素残留

建立了高效液相色谱-串联质谱(HPLC-MS/MS)测定猪肉样品中新型兽药泰拉霉素残留的方法.样品用V(甲醇): V(0.1% H3PO4)=70: 30混合溶液提取,经离心后用PCX固相萃取小柱净化, 以SymmetryC8色谱柱为分离柱,在串联质谱多反应监测(MRM)模式下检测,内标法定量.方法的线性范围为10～500 μg/kg,检出限为5.0 μg/kg,在3个浓度水平(10,20和50 μg/kg)进行添加实验,平均回收率为93.1%～105.5%; 批内相对标准偏差为1.5%～4.6%; 批间相对标准偏差为1.8 %～5.6%.     

液相色谱-串联质谱法测定大鼠血浆中福斯克林

建立了测定大鼠血浆中福斯克林的液相色谱-串联质谱法(LC-MS/MS).血浆样品经液-液萃取后,以V(甲醇):V(10 mmol/L 醋酸铵):V(甲酸)=75:25:0.1为流动相,用Hypersil ODS柱分离,流速0.8 mL/min(柱后分流50%),通过电喷雾离子化四极杆串联质谱,以多反应监测方式(MRM)检测.用于定量分析的离子分别为m/z 428/375(福斯克林)和m/z 494/369(格列本脲,内标).福斯克林血浆浓度测定方法的线性范围为0.8～800 μg/L; 日内、日间精密度(RSD)均小于10%;准确度(RE)小于±9%.每个样品测试时间4.5 min.应用此法测试了大鼠口服或静注福斯克林后的血药浓度.     

鱼腥草中3种有效成分含量的测定

建立鱼腥草不同品种、不同部位绿原酸、芸香苷和槲皮素的测定方法. 以90% EtOH为溶剂, 采用索氏提取器提取, 利用HPLC测定3种活性成分的含量. 采用DiamonsilTMC18 (4.6 mm×150 mm, 5 μm)为色谱柱, 流动相分别为0.06 mol/L V(NaH2PO4)∶V(MeOH)＝7.3∶2.7、 V(MeOH)∶V(H2O)∶V(HAc)＝48∶50∶2, 流速为1 mL/min, 绿原酸检测波长为326 nm, 芸香苷和槲皮素为254 nm. 绿原酸、芸香苷、槲皮素的线性范围分别为4.6～30.7 μg/mL、 0.30～7.5 μg/mL、 0.034～0.85 μg/mL, 平均回收率和RSD分别为99.3%、 1.0%, 98.9%、 1.6%, 98.7%、 0.7%. 该方法可用于鱼腥草原料选择和制剂质量的控制.     

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.     

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.     

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.     

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.