超高效液相色谱-三重四级杆串联质谱法同时测定血样中7种常见毒品

建立超高效液相色谱-三重四级杆串联质谱(UPLC-MS/MS)同时检测血样中甲卡西酮、右美托咪啶、甲苯噻嗪、氯胺酮、哌替啶、氟哌啶醇和丁丙诺啡7种常见毒品的方法。血样经Waters Oasis MCX固相萃取柱净化后,采用ACQUITY UPLCHSS C18色谱柱(150 mm×2. 1 mm,1. 8μm)分离,流动相为乙腈-水/甲酸/甲酸铵,梯度洗脱,电喷雾电离正离子模式(ESI+),多反应监测方式(MRM)检测。7种目标物在1~200ng·mL~(-1)范围内的线性关系良好,检出限和定量限分别为0. 05~0. 1 ng·mL~(-1)和0. 2~0. 5 ng·mL~(-1),回收率在83. 2%~115. 4%之间,相对标准偏差小于7. 9%。本文方法可以同时对血样中7种常见毒品进行检测,能够满足实际检案的要求。     

液相色谱-质谱法测定人体血浆中非那雄胺含量

建立了测定人体血浆中非那雄胺药物浓度的液相色谱-质谱分析方法。色谱柱为Hypersil-Keystone C_(18)柱,流动相为乙腈∶水(含0.2%三氯乙酸)=55∶45(V/V),质谱选择电喷雾正离子源(ESI+),选择离子模式(SIM)监测,非那雄胺和内标卡马西平质荷比分别为m/z373和m/z237。血浆样品经乙腈去蛋白、离心和吹干后,残渣用流动相溶解。当非那雄胺的浓度在0.5~120ng·mL~(-1)范围时线性关系良好(r=0.999),检测限(S/N=3)为0.02ng·mL~(-1);日间和日内测定的精密度(RSD)分别在6.4%~2.2%和5.5%~1.7%之间;加标0.5ng·mL~(-1)、40ng·mL~(-1)和80ng·mL~(-1)非那雄胺的平均回收率(n=6)分别为108.5%、101.2%和98.7%。方法快速、准确和灵敏,已成功用于人血浆中非那雄胺浓度的测定和人体药代动力学研究。     

UPLC-MS/MS法测定7类化妆品中4-氨基联苯

建立了超高效液相色谱-串联质谱(UPLC-MS/MS)检测化妆品中4-氨基联苯的方法。化妆品样品经溶剂超声提取、净化(液液萃取或固相萃取),氮气吹至近干并定容后,通过高效液相色谱-串联四极杆质谱仪检测。分离柱为Waters Acquity BEH C18柱(1.7μm,2.1 mm×100 mm);流动相为0.3%甲酸水溶液-乙腈;流速0.5 mL·min-1。7种不同基质样品中4-氨基联苯的检测限均小于1.0ng·g-1。7种不同基质样品中4-氨基联苯的回收率为85.3%～111.2%,相对标准偏差(RSD)为0.93%～4.11%(n=3),在2.5ng·mL-1～250ng·mL-1浓度范围内呈良好的线性关系,线性回归系数r2均大于0.999。     

介质液液萃取-HPLC-MS/MS法同时测定血液中5种吩噻嗪类药物

结合介质液液萃取技术建立了高效液相色谱-串联质谱法同时测定血液中5种吩噻嗪类药物的检测方法。采用Kinetex C18色谱柱,以0.1%甲酸+5 mmol·L~(-1)乙酸铵水溶液-乙腈为流动相,梯度洗脱分离。在电喷雾正离子模式下,以多反应检测(MRM)扫描模式采集数据对血液中的5种吩噻嗪类药物进行定性与定量分析。5种吩噻嗪类药物在5.0~100 ng·m L~(-1)范围内具有良好的线性关系,相关系数均大于0.9939;检出限在0.07~0.30 ng·m L~(-1)之间;添加浓度水平为10,20和50 ng·m L~(-1)时,方法的平均回收率为78.2%~105.7%;相对标准偏差为3.5%~10.8%。该方法可用于血液中五种吩噻嗪类药物的法庭与临床毒物分析。     

基质固相分散萃取-高效液相色谱-串联质谱法分析拟南芥中的赤霉素

建立了基质固相分散萃取-高效液相色谱-串联质谱法(MSPD-HPLC-MS/MS)同时测定拟南芥中3种赤霉素GA1, GA3和GA4的分析方法。将拟南芥样品与C18填料混合研磨制成MSPD柱,并采用80%冷甲醇洗脱。采用反相C18色谱柱进行分离,以0.05%甲酸水溶液和乙腈为流动相进行梯度洗脱,采用电喷雾离子源负离子模式(ESI~)电离,多反应监测模式检测。对样品前处理条件、色谱分离条件和质谱检测条件进行了优化,结果表明,在最优条件下,3种赤霉素在10～300 ng/g范围内均呈良好线性关系,相关系数(r2)均大于0.98,检出限在1.1～4.1 ng/g之间。在10～50 ng/g添加水平下,平均回收率范围为54.7%～102.6%,相对标准偏差（RSD,n=3)为3.2%～12.8%。该方法操作简单、灵敏度高、选择性好、回收率高,适合拟南芥中GA1、GA3、GA4含量的测定。     

超高效液相色谱-串联质谱法测定保健食品中7种非法添加的化学镇静剂

采用固相萃取-超高效液相色谱-串联质谱法测定保健食品中7种非法添加的化学镇静剂的含量。保健食品样品以甲醇为溶剂进行提取,经高速离心处理后,取上清液,经Oasis MCX固相萃取柱净化。所得净化液以Zorbax-SB-C18色谱柱为分离柱,以不同体积比的0.1%(体积分数)甲酸溶液和乙腈混合液为流动相进行梯度洗脱,采用电喷雾正离子源多反应监测模式检测。7种化合物的质量浓度均在0.10~30.0μg·L~(-1)范围内与其峰面积呈线性关系,方法的测定下限(10S/N)在0.1~2.1μg·kg~(-1)之间。在0.30,3.0,10.0μg·L~(-1)等3个浓度水平进行加标回收试验,回收率在76.7%~104%之间,测定值的相对标准偏差(n=6)在2.1%~9.8%之间。     

气相色谱-质谱法测定汽车材料中7种苯系物

采用气相色谱-质谱法测定汽车材料中7种苯系物的含量。在气相色谱分离中用HP-5MS色谱柱为固定相,在质谱分析中采用全扫描和选择离子监测模式。以氘代苯-D6为内标物。7种苯系物的线性范围均为1 0~1 000ng,检出限(3s)在9~18ng之间。苯系物测定结果的相对标准偏差(n=6)在0.81%~2.4%之间,加标回收率在99.0%~102%之间。     

LC-MS/MS法检测水环境中的双氯芬酸钠

本研究报道了一种高灵敏度的测定水环境中双氯芬酸钠残留的LC-MS/MS法。色谱和质谱条件为:色谱柱为ACQUITY UPLC?BEH C_(18)柱(50 mm×2. 1 mm,1. 7μm),流动相为乙腈-水(60∶40,V/V),流速0. 30mL·min~(-1); AB SCIEX QTRAP 5500质谱仪,电喷雾离子源(ESI),雾化器压力30 psi,离子源温度550°C。双氯芬酸钠分子量为318. 13,在负离子扫描模式下,一级和二级质谱分别得到m/z为293. 8和249. 9的峰。此法做出的双氯芬酸钠标准曲线浓度范围为0. 20~20. 00 ng·mL~(-1)(r=0. 9994),定量下限为0. 05 ng·mL~(-1)。双氯芬酸钠的回收率在67. 2%~104%之间。该方法灵敏度高,操作简便快速,可用于水环境中双氯芬酸钠的检测。     

UPLC-MS/MS测定铁观音茶中21种游离氨基酸含量

建立了一种高效、快速可直接测定茶叶中21种游离氨基酸的超高效液相色谱-串联质谱(UPLC-MS/MS)检测方法。茶叶样品经粉碎、超声提取、离心净化、定容后,采用Capcell Pak C18柱(5μm, 2.1×150mm)进行梯度洗脱分离,流动相为0.3%甲酸水溶液-乙腈,流速0.4mL·min~(-1)。茶叶中21种游离氨基酸在7.2～335.5ng·mL~(-1)范围内的线性关系良好(R~2≧0.996),检出限0.1～3.8 mg·kg~(-1),定量限0.4～12.5 mg·kg~(-1),加标回收率72.1%～104.2%,相对标准偏差RSD≦5.3%(n=6)。该方法分析速度快、灵敏度高、选择性好,适用于茶叶中21种游离氨基酸的快速检测和定量分析。     

超声萃取-气相色谱-质谱法测定卷烟主流烟气中的6种挥发酚

采用气相色谱-质谱法测定卷烟主流烟气中的苯酚、对甲酚、间甲酚、邻甲酚、对苯二酚和间苯二酚等6种挥发酚的含量。用剑桥滤片在标准抽吸条件下采集5支卷烟烟气粒相物,用甲醇超声萃取10min。所得萃取液用DB-624毛细管色谱柱(30m×0.25mm,1.4μm)为固定相进行分离,在质谱分析中采用全扫描和选择离子监测模式。以苯酚-D_5为内标物。方法的检出限(3S/N)在10~16ng·支~(-1)之间,测定下限(10S/N)在28~40ng·支~(-1)之间。加标回收率在84.6%~99.1%之间,测定值的相对标准偏差(n=6)在2.1%~6.4%之间。     

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.     

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.     

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.