QuEChERS结合超高效液相色谱-串联质谱法检验腐败血中4-甲基甲卡西酮和甲卡西酮

建立了腐败血中4-甲基甲卡西酮和甲卡西酮的超高效液相色谱-三重四级杆串联质谱(UPLC-MS/MS)检测方法。腐败血样品经乙腈水混合溶液(乙腈:水=4:1,V/V)提取,无水MgSO_4脱水和C_(18)吸附剂净化。选用Waters BEH C_(18)色谱柱分离,0.1%甲酸-水(5 mmol/L乙酸铵)和乙腈作为流动相进行梯度洗脱,电喷雾电离,正离子(ESI~+)模式扫描,多反应监测(MRM)模式检测。4-甲基甲卡西酮和甲卡西酮在0.5～100 ng/mL范围内线性关系良好(R~2≧0.9993),检出限(S/N=3)分别为0.01 ng/mL(4-甲基甲卡西酮)和0.03 ng/mL(甲卡西酮),定量限(S/N=10)分别为0.1 ng/mL(4-甲基甲卡西酮)和0.5 ng/mL(甲卡西酮)。     

超高效液相色谱-四极杆飞行时间质谱同时检测血样中4种卡西酮类新精神活性物质

建立了同时检测血样中3,4-亚甲二氧基甲卡西酮(Methylone)、3,4-亚甲二氧基乙卡西酮(Ethylone)、4-氯甲卡西酮(4-CMC)、4-氯乙卡西酮(4-CEC)4种卡西酮类新精神活性物质的超高效液相色谱-四极杆飞行时间质谱法(UHPLC-QTOF MS/MS)。取0.5 mL血液,按体积比5∶2∶13将血液、水和乙腈混合,涡旋振荡1 min,以12 000 r/min离心15 min将蛋白沉淀,取上清液待测。采用Acquity UPLC^?BEH C₁₈色谱柱(2.1 mm×100 mm,1.7μm)分离,0.1%甲酸-水(5 mmol/L乙酸铵)和乙腈作为流动相进行梯度洗脱,采用多反应监测(MRM)模式,正离子[M+H]⁺扫描检测。结果表明,4种目标药物在5～500 ng/mL质量浓度范围内线性关系良好,检出限为2 ng/mL,定量下限为5 ng/mL,回收率为87.3%～111%,日内和日间相对标准偏差分别不大于8.1%和8.6%。该方法可同时检测血样中4种卡西酮类新精神活性物质,满足实际检验需要。     

液相色谱-四级杆飞行时间质谱法检验血液中的3-氯甲卡西酮

本研究建立了液相色谱-四级杆飞行时间质谱(LC-QTOF-MS)检验血样中3-氯甲卡西酮(3-CMC)的方法。血液经1:2体积的乙腈沉淀蛋白后,采用Agilent?ZORBAX Eclipse Plus C18色谱柱(3.0 mm×150 mm,1.8μm)分离,0.1%(v/v)甲酸-水(5mol·L~(-1)乙酸铵)和乙腈作为流动相梯度洗脱,电喷雾双喷离子源电离正离子模式(Dual AJS ESI+)扫描。3-氯甲卡西酮在5～500ng·mL~(-1)范围内线性关系良好,检出限和定量限分别为2ng·mL~(-1)和5ng·mL~(-1),回收率在103.6%～113.7%之间,日内精密度小于8.1%,日间精密度小于11.8%。本方法可以对血液中的3-氯甲卡西酮进行定性定量检测,能够满足实际检案的要求。     

快速溶剂萃取-气相色谱/质谱法分析血液中的甲卡西酮

建立血液中甲卡西酮快速溶剂萃取（ASE）-气相色谱/质谱（GC/ MS）分析的新方法. 通过优化 ASE 的萃取条件（溶剂、温度及时间）,对血液中的甲卡西酮进行有效提取,之后用 GC/ MS 进行定性、定量分析. 方法检出限为0. 02 mg / L,定量限为0. 1 mg / L. 血液中甲卡西酮在0. 5、1. 0 和2. 0 mg / L 3 个添加水平的平均回收率在96. 70% ~99. 27%之间,甲卡西酮在0. 1 ~ 50 mg / L 的浓度范围内线性良好. 方法快速、简便、高效且操作自动化,适用于血液中甲卡西酮的检验鉴定.     

超高效合相色谱-质谱法对甲卡西酮对映异构体的手性分离和定量检测

建立了超高效合相色谱-质谱法(UPC2-MS)对甲卡西酮(MC)对映异构体进行手性分离和定量检测。使用Acquity UPC² Trefoil CEL2 (2.5μm, 3.0 mm×150 mm)手性色谱柱,以超临界流体CO₂为主要流动相,含10 mmol/L甲酸铵和0.1%甲酸的异丙醇为改性剂进行梯度洗脱,可以在13 min内实现2个对映异构体的基线分离。在三重四极杆质谱多反应监测(MRM)模式下,2个对映异构体的检出限为0.5 ng/mL,定量限为1.0 ng/mL,在1～100 ng/mL质量浓度范围内线性关系良好,线性相关系数(R²)≥0.999, 10种常见毒品和药品对检测均无干扰。对实际缴获毒品的检测结果表明：直接作为毒品销售的MC主要为外消旋体,而非法制造麻黄碱的地下窝点缴获的MC以S构型为主。     

甲卡西酮的液相色谱法测定

建立了高效液相色谱法测定甲卡西酮的含量。采用AgilentZorbax SB-Phenyl柱,流动相为三氟乙酸（pH3．51-乙腈（体积比85：15）,流速0．2mL／min,检测波长254nm。甲卡西酮的浓度在0.5—1000μg／mL范围内与色谱峰面积呈良好的线性关系,F=0．999,日内与日间保留时间和峰面积测定结果的标对标准偏差均不大于1．48％（n=6）,检出限为0．063μg／mL,平均加标回收率为118.2％。该方法适用于甲卡西酮的定性定量分析。     

LC-MS/MS法快速测定吡罗昔康制剂中吡罗昔康含量

建立了快速液相色谱-质谱/质谱联用法测定吡罗昔康制剂中吡罗昔康含量的方法。样品以0.1 mol/L盐酸甲醇溶液提取、微孔滤膜过滤、离心后,通过电喷雾离子化(ESI),采用多反应检测(MRM)方式进行正离子检测,用于定量分析的检测离子为m/z 332.2→94.8。采用Shim-pack XR-ODS(3.0 mm×75mm,2.0μm)柱分离,以乙腈-水-甲酸(60:40:0.1,V/V/V)为流动相,流速为0.40 mL/min,在3 min内完成吡罗昔康定量分析。线性范围为2.5～1000.0ng/mL,最低检测限为2.5 ng/mL;日内测定的相对标准偏差小于3.2%,日间测定的相对标准偏差小于3.8%。方法可作为吡罗昔康制剂的质量中吡罗昔康控制方法,并可用于少量血浆样品的测定,也适用于药物代谢动力学研究。     

液相色谱-串联质谱法同时测定人血清中皮质酮与皮质醇

建立了同时测定人血清中皮质酮和皮质醇的液相色谱-串联质谱法。血清经正己烷除脂净化、叔丁基甲醚提取后,以乙腈-0.1%甲酸溶液(含0.01 mol/L甲酸铵)为流动相,流速为0.3 mL/min。用Agilent E-clipse Plus-C18色谱柱(150 mm×2.1 mm,3.5μm)分离,正离子模式下进行串联质谱检测。皮质酮和皮质醇浓度在0.5～200 ng/mL范围内线性关系良好,相关系数(r2)分别为0.999 7、0.999 4。皮质酮和皮质醇分别在5.0、25.0、75.0 ng/mL和0.5、2.5、10.0 ng/mL 3个加标水平下的平均回收率为86.6%～102.7%,相对标准偏差不大于7.1%,检出限分别为0.1 ng/mL和0.05 ng/mL。该方法操作简便、灵敏度高、重现性好、定性定量准确,适用于同时测定血清中的内皮质酮和皮质醇。     

超高效液相色谱-串联质谱法同时测定血液中115种农药

建立了超高效液相色谱-串联质谱法(UPLC-MS/MS)一针进样同时测定血液中115种农药的方法。血液样品与提取剂甲醇按1∶5体积比进行蛋白沉淀,涡旋振荡2 min,以12 000 r/min离心10 min,取上清液进行UPLC-MS/MS分析。质谱分析采用电喷雾离子源(ESI),正离子模式和负离子模式同时切换采集。结果表明,115种目标农药在1～200 ng/mL质量浓度范围内线性关系良好(r>0.99),13%的目标农药检出限(S/N≥3)为0.2 ng/mL,其余目标物均为0.1 ng/mL,所有目标农药的定量下限(S/N≥10)均为1 ng/mL。在10、50、100 ng/mL加标水平下,方法的基质效应为81.8%～115%,目标农药的回收率为80.4%～109%,日内精密度(Intra-RSD)为1.6%～11%,日间精密度(Inter-RSD)为1.9%～13%。该方法简便快速、灵敏度高、稳定性好,适用于血液样品中多农药的定性定量分析。     

液相色谱-串联质谱法测定人血浆中儿茶酚胺的含量

建立人血浆中儿茶酚胺液相色谱-串联质谱(LC-MS/MS)的检测方法。采用Agilent Zorbax Eclipse XDB-C18(4.6 mm×150 mm,5μm)柱子,柱温25℃,流动相为V(乙腈)∶V(0.1%甲酸溶液)=10∶90,流速0.6 mL/min,进样量20μL;电喷雾离子源(ESI),正离子检测,采用多反应监测(MRM)方式进行定量分析。肾上腺素、去甲肾上腺素和多巴胺的最小检测限(LOD)在4.3,2.4和6.6ng/mL之间,浓度在0~500 ng/mL范围内线性良好(r=0.9921),平均回收率在85.8%~93.4%之间,日内、日间精密度RSD为9%(n=5)。结果表明该方法专属性强、灵敏及准确,可以适用于人血浆儿茶酚胺的快速分析。     

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%.     

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.     

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.     

A general and convenient synthesis of 4-(tosylmethyl)semicarbazones and their use in amidoalkylation of hydrogen,heteroatom, and carbon nucleophiles

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.     

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.     

Synthesis of novel chiral bidentate hydroxyalkyl-N-heterocyclic carbene ligands and their application in palladium-catalyzed Mizoroki–Heck couplings and asymmetric addition of diethylzinc to benzaldehyde

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.