超高效液相色谱-四极杆飞行时间质谱快速检测动物饲料中10种违禁精神药物

建立了测定动物饲料中三唑仑、艾司唑仑、硝西泮、地西泮、异丙嗪、氯氮平、唑吡坦、甲硫哒嗪、氯丙嗪和咪达唑仑10种违禁精神药物的超高效液相色谱-四极杆飞行时间质谱(UPLC-Q-TOF-MS)方法。样品经混合溶剂甲醇-0.1 mol/L HCl(9:1, v/v)振荡提取,再用MCX固相萃取柱净化处理后,采用UPLC-Q-TOF-MS分析检测。10种化合物在5～100 μg/L范围内均呈良好的线性关系,线性相关系数均大于0.99。本方法的硝西泮、唑吡坦和甲硫哒嗪的定量限(LOQ,以信噪比为10计)为8 μg/kg,三唑仑、艾司唑仑、地西泮、异丙嗪、氯丙嗪和咪达唑仑为10 μg/kg,氯氮平为20 μg/kg。3个添加水平(LOQ、2LOQ、4LOQ)的回收率试验结果表明,10种化合物的回收率在60.6%～108.5%范围内,相对标准偏差均小于10%。本方法可用于动物饲料中违禁精神药物的准确测定。     

多壁碳纳米管对微量苯二氮卓类药物的吸附性能研究

研究了静态吸附条件下多壁碳纳米管(MWCNTs)对地西泮、艾司唑仑、阿普唑仑和三唑仑 4种苯二氮卓类药物的吸附性能,10 min内能达到吸附平衡.MWCNTs对药物的吸附容量随药物浓度的增加而增加,最小初始浓度时MWCNTs对4种药物的静态吸附容量分别为7.95、7.88、7.99和7.73 mg/g,吸附容量较大.295、303和313 K温度下的吸附实验表明,吸附容量随温度的升高而减小,降低温度有利于药物的吸附.对不同温度下的吸附等温线采用Freundlich和Langmuir方程进行拟合,结果显示Langmuir方程具有更好的拟合效果.在动态吸附条件下穿透体积的测定显示MWCNTs对药物也具有大的吸附容量且萃取回收率高达90%以上.     

脉冲不分流进样气相色谱-质谱法分析血浆中的10种镇静催眠药

采用脉冲不分流进样技术建立了血浆中10种镇静催眠药(巴比妥、异戊巴比妥、苯巴比妥、奥沙西泮、地西泮、硝西泮、氯硝西泮、艾司唑仑、阿普唑仑、三唑仑)的气相色谱-质谱(GC-MS)快速定性定量分析方法.血浆样品经0.1 mol/L 氢氧化钠溶液碱化后,用乙酸乙酯萃取;萃取液经氮气吹干,用乙酸乙酯溶解后进行GC-MS分析,所...     

UPLC - ESI MS/MS法测定动物饲料中苯二氮卓类药物

建立了超高效液相色谱-电喷雾串联质谱(UPLC - ESI MS/MS)同时检测动物饲料中地西泮、奥沙西泮、硝西泮、三唑仑、艾司唑仑和咪达唑仑6种苯二氮卓类药物的方法.饲料样品采用碱性叔丁基甲醚提取,Oasis MCX固相萃取柱净化,反相色谱柱分离,以0.1％甲酸和乙腈为流动相进行梯度洗脱,正离子模式扫描,多反应监测模...     

液相色谱串联质谱法快速测定猪尿中10种镇静剂类药物残留量

建立了快速测定猪尿中10种镇静剂类药物(噻拉嗪、阿扎哌隆、氟哌啶、氟哌啶醇、艾司唑仑、硝西泮、地西泮、奥沙西泮、氯丙嗪和奋乃静)残留量的液相色谱串联质谱方法.猪尿样品离心后过C18固相萃取小柱,用甲醇-乙酸乙酯(1∶ 4, V/V)混合溶剂洗脱,氮气吹干后用0.1%甲酸溶液溶解进行仪器分析.采用Eclipse XDB-C18色谱柱分离,以乙腈和0.1%甲酸溶液为流动相进行梯度洗脱,电喷雾正电子(ESI+)模式电离,多反应监测(MRM)模式检测,基质校准进行定量分析.10种镇静剂类药物在5～200 μg/L范围内呈良好的线性,线性相关系数均大于0.99.方法检出限为0.11～0.52 μg/L; 定量限为0.20～0.91 μg/L.添加浓度为1.0, 2.0和10.0 μg/L时,平均回收率在74.6%～115 %之间,批内和批间相对标准偏差均小于15%.     

保健食品中9种镇静催眠类药品的UPLC-MS/MS法检测及质谱裂解特征的研究

建立了同时测定保健食品中9种镇静催眠类化合物(氯美扎酮、三唑仑、阿普唑仑、艾司唑仑、地西泮、硝西泮、奥沙西泮、劳拉西泮、氯氮卓)的超高效液相色谱-串联质谱(UPLC-MS/MS)分析方法,并研究了其质谱裂解规律。样品以甲醇为提取溶剂,经Zorbax SB-C18(3.5μm,2.1 mm×150 mm)色谱柱分离,乙腈-水(含0.1%甲酸)为流动相梯度洗脱,流速为0.3 m L/min。采用电喷雾离子源(ESI),正离子多反应监测(MRM)扫描方式检测,基质匹配标准曲线法定量。9种药物在0.5~50μg/L范围内线性关系良好,相关系数(r2)均大于0.99,定量下限为1.6~9.2μg·kg~(-1)。低、中、高3个加标水平下的平均回收率为78.1%~101.2%,日内相对标准偏差(RSD)为1.4%~9.7%,日间RSD为2.0%~11.2%。该法简便、快速、准确可靠,适合于保健食品中非法添加镇静催眠类药品的高通量筛查。而对目标化合物碎片离子及质谱裂解规律的研究,也为其定性鉴别和定量分析提供了参考。     

超高效液相色谱-串联质谱法测定毛发中7种新型苯二氮■类策划药物的含量

由于新型苯二氮■类策划药物具有用量小、药效强、体内代谢快和含量低等特点,很难在受害人的血液和尿液中检出,而毛发具有检出时效长、易获取和易保存的优势,因此提出了题示方法.取剪至1～2 mm的毛发20 mg,加入1 m L含内标(1μg.L^-1阿普唑仑Gd₅)提取剂,于-50℃预冷5min,冷冻研磨两次,每次90s,中间间隔60s,并离心5min,取上清液浓缩至干,用100μL甲醇复溶,经0.22μm有机滤膜过滤.滤液在Acquity UPLCHSST3色谱柱上进行分离,经不同体积比的0.1%(体积分数,下同)甲酸溶液G含0.1%甲酸的乙腈溶液的混合液为流动相进行梯度洗脱,采用电喷雾离子源正离子模式(ESI⁺)扫描,多反应监测(MRM)模式检测,以保留时间和特征离子定性,内标法定量.结果表明,7种新型苯二氮■类策划药物(瑞马唑仑、科纳唑仑、氟阿普唑仑、氟溴唑仑、玻玛唑仑、依替唑仑、溴替唑仑)工作曲线的线性范围为1～500pg.mg^-1,检出限(3S/N)为0.11～0.35pg.mg^-1     

气相色谱电子捕获检测法测定人尿中α羟基三唑仑及α羟基阿普唑仑

建立了尿中三唑仑的代谢物α羟基三唑仑和阿普唑 仑的代谢物α羟基阿普唑仑的气相色谱电子捕获检测法。代谢物用N,O双三甲基硅烷基三氟乙酰胺（BSTFA）进行三甲基硅烷衍生化后进行检测。尿中代谢物的检出限约为1μg/L（S/N=3）,至少可检出口服治疗量药物人体24h之内排泄尿中的代谢物,满足麻醉后犯罪案件中药物检验的要求。     

气相色谱-质谱同时测定猪肉中3种巴比妥药物残留

建立了固相萃取-气相色谱-质谱同时分析猪肉中3种巴比妥类药物残留量的方法。对猪肉样品的乙腈提取、C18固相萃取柱净化和碘甲烷甲基化条件进行了优化。采用HP-5毛细管柱分离,电子轰击电离源质谱选择离子模式(SIM)检测(巴比妥m／z126,169,183,184;异戊巴比妥m／z169、170、184、226;苯巴比妥m／z175、232、245、260;dwell time80s),外标法定量(定量离子m／z分别为169、169和232)。3种巴比妥药物的添加标准曲线线性回归系数均在0．99以上;线性范围2．5～50μg/kg,回收率为65％～112％,相对标准偏差5．4％～17．2％,检出限均为1μg/kg。     

液相色谱-串联质谱法检测淡水养殖环境中地西泮及其代谢物

建立了养殖水、植物、沉积物和鲫鱼中地西泮及其代谢物(去甲西泮、奥沙西泮和替马西泮)的液相色谱-串联质谱检测方法。养殖水经0.45μm玻璃纤维膜过滤,用氨水调至pH 8.0后通过反相固相萃取柱(HLB)净化;植物和沉积物经盐析提取后,通过QuEChERS方法净化上样;鲫鱼样品经盐析提取后,通过固相萃取柱(Prime HLB)净化上样。采用Luna C₁₈柱(100 mm×2.1 mm,1.6μm)进行分离,多反应监测(MRM)模式进行测定,外标法定量。结果表明：地西泮及其3种代谢物在0.1～10μg/L质量浓度范围内呈良好的线性关系(r²>0.999)。4种目标物在养殖水体中的检出限为1.0～1.2 ng/L,定量下限为5.0～6.0 ng/L;在植物、沉积物和鲫鱼中的检出限为0.03～0.10μg/kg,定量下限为0.10～0.25μg/kg。在低、中、高3个加标水平下,地西泮及其代谢物的回收率为83.4%～106%,相对标准偏差(RSD,n=6)为1.2%～9.4%。该方法成功应用于养殖水、沉积物、植物和鲫鱼样品中地西泮及其代谢物的检...     

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.