支持向量回归算法应用于分光光度法同时测定安替比林、巴比妥和氨基比林

采用均匀设计法制备不同含量配比的安替比林、巴比妥、氨基比林校正集样品,用化学计量学方法--支持向量回归(SVR)方法建立校正模型,并对安替比林、巴比妥和氨基比林的模拟样品及安痛定注射液样品进行测定.结果表明,三种成分的加标回收率均在98%～104%之间,测定结果的相对标准偏差为0.48%～1.24%.     

铁氰化钾-钙黄绿素体系后化学发光反应测定氨基比林

研究发现,氨基比林在铁氰化钾-钙黄绿素化学发光反应体系中的后化学发光反应。优化了反应条件,建立了一种利用后化学发光反应测定氨基比林的流动注射化学发光方法。方法的检出限为20μg/L;相对标准偏差为2.0%(2.0mg/L氨基比林,n=11);线性范围为1.0×10-4~1.0×10-2g/L。此法已用于复方氨林巴比妥注射液中氨基比林含量的测定,结果与药品标准方法测定值一致。     

混合线性分析法同时测定安痛定注射液中三组分含量

将一种新近发展的多元校正方法——混合线性分析法，用于安痛定注射液中氨基比林、安替比林、巴比妥含量的同时测定。在220～250nm内取16个波长测量7组标准混合溶液的吸光度矢量作为校正集，以最小二乘法求得系数矢量作为各组分的纯光谱，用混合线性分析法进行数据处理。氨基比林、安替比林、巴比妥的标准回收率分别为99．0％～100．3％、99．0％～100．8％和98．5％～101．1％。用于安痛定注射液中氨基比林、安替比林、巴比妥三组分含量的测定，经t检验，其测定结果与标准法相比，两者间无显著性差异。     

流动注射化学发光法测定安痛定注射液中安替比林

1　引　　言安痛定注射液是一种具有解热镇痛的复方制剂 ,主要含氨基比林及少量的安替比林、巴比妥。对安替比林的测定 ,化学发光分析法还未见报道。研究发现 ,在磷酸介质中 ,过氧化氢存在下 ,高碘酸钠氧化安替比林产生强烈的化学发光 ,发光强度在一定范围内与安替比林的浓度呈线性关系 ,且注射液中氨基比林与巴比妥不干扰测定。据此 ,结合流动注射技术建立了一种在ＮａＩＯ4 Ｈ3ＰＯ4 Ｈ2 Ｏ2 安替比林发光体系中测定安痛定注射液中安替比林的化学发光新方法。方法的检出限为 2 3× 1 0 - 5ｇ Ｌ安替比林 ;线性范围为 1 0×1 0 - 4 ～ 7…     

牛和猪肌肉组织中安乃近代谢物残留的液相色谱-串联质谱分析

建立了牛和猪肌肉组织中安乃近代谢残留物4-甲酰氨基安替比林、4-乙酰氨基安替比林、4-氨基安替比林和4-甲基氨基安替比林的高效液相色谱-串连质谱(LC-M/MS)测定法。肌肉组织样品均质后,采用硫酸钠提取液提取。过滤后,过C18固相萃取(SPE)柱净化,采用LC-MS/MS电喷雾电离(ESI),多反应监测(MRM)模式检测。4-甲酰氨基安替比林和4-乙酰氨基安替比林采用外标法定量,而4-甲基氨基安替比林和4-氨基安替比林则是以4-异丙基氨基安替比林作为内标物采用内标法进行定量;4-甲酰氨基安替比林和4-氨基安替比林的检出限为1.0μg/L;4-乙酰氨基安替比林和4-甲基氨基安替比林的检出限则为0.5μg/L;在添加浓度为5~200ng/g范围内,4-甲酰氨基安替比林的回收率为81.6%~94.0%;4-乙酰氨基安替比林的回收率为81.2%~90.2%;4-氨基安替比林的回收率为82%~101%;4-甲基氨基安替比林的回收率为78.5%~87.0%;相对标准偏差(RSD)均在7%以内。     

固相萃取/离子阱气相色谱质谱联用对血液中多种安眠药物的同时测定

建立了气相色谱-质谱联用测定血液中多种安眠药物的分析方法,通过固相萃取提取并富集血液样品中的9种常见巴比妥类、吩噻嗪类和苯二氮杂类安眠药物,采用离子阱二级质谱检测其含量。通过优化萃取溶液pH值及气相色谱-质谱联用分析条件,对9种安眠药物进行了定量分析。采用离子阱串联质谱(MS/MS)技术消除基底干扰,给出被测物结构信息。9种安眠药物的检出限为0.04~0.10 mg/L,回收率为78%~93%。方法用于人心血中安眠药物的检测,检出安定0.6 mg/L。该方法高效、简单、灵敏度高,可用于血液中巴比妥类、吩噻嗪类和苯二氮杂类安眠药物的同时测定。     

血液中4种巴比妥类药物的固相萃取及液相质谱法分析

建立了血液中加巴比妥、苯巴比妥、异戊巴比妥、司可巴比妥四种巴比妥类药物的固相萃取前处理方法及液质联用分析方法。研究了酸性、中性、碱性提取条件及选用几种不同固相萃取柱,结果表明p H=4的酸性提取条件下及HLB固相萃取柱较优。四种巴比妥类药物的液质分析检出限是巴比妥(5 ng/mL)、苯巴比妥(10 ng/mL)、异戊巴比妥(2 ng/mL)、司可巴比妥(5 ng/mL),线性范围是10~250 ng/mL。该方法简单易操作,回收率高,为血液中巴比妥类药物的定性定量分析提供了参考。     

水中挥发酚的在线蒸馏-固相萃取分离富集及测定

在顺序注射系统中实现了挥发酚的快速自动在线蒸馏,并用AmberliteXAD-7树脂微填充柱对其与4-氨基安替比林的衍生物在线固相萃取,被富集的衍生物可用少量乙醇有效地洗脱回收,以分光光度法检测.方法可用于较高浓度挥发酚(mg/L)样品的测定,也可根据需要适当增大进样体积,经富集后实现更低浓度水平(μg/L)挥发酚的测定.当富集过程中进样体积为4mL时,方法测定挥发酚的线性范围为0.004~0.3mg/L,检出限为0.002mg/L,相对标准偏差为1.4%(0.1mg/L,n=9).对多种实际水样中的挥发酚进行了测定,加标回收实验的回收率在96%~102%之间.     

多级溶剂萃取-气相色谱法测定啤酒中的游离脂肪酸

啤酒中含量极低、极不稳定的游离脂肪酸是影响啤酒风味重要因素之一。本文采用溶剂萃取和气相色谱联用技术,对啤酒不良风味物质游离脂肪酸进行了检测。啤酒样品经3次萃取(有机溶剂萃取、碱液反萃取、有机溶剂萃取)后,通过甲醇-硫酸甲酯化处理,最后用正己烷萃取浓缩进行气相色谱(GC)分析。该方法中以辛酸、癸酸和月桂酸为代表的平均回收率分别为86.26%、92.19%和83.57%。辛酸、癸酸、月桂酸、棕榈酸在2.326~2326 mg/L,0.362~362 mg/L,0.250~250 mg/L,0.330~330 mg/L范围内线性良好,相关系数在0.9996~0.9999之间。     

氨基比林的循环伏安测定及其电化学行为研究

在0.05 mol/L Tris-HCI(pH=8.5)的底液中,采用循环伏安法测定氨基比林,得到一良好的氧化峰,峰电位Ep=0.25 V,峰电流Ip与氨基比林的浓度在8.0×10-7～1.6×10-5mol/L范围内呈线性关系,相关系数r=0.9969,检出限为9.0×10-8mol/L.采用本法测定安痛定注射液中氨基比林的含量,回收率在95.0%～106.2%相对标准偏差(RSD)为1.68%.研究了氨基比林在玻碳电极上的电化学行为,结果表明氨基比林的电极过程具有吸附性和不可逆性.     

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.     

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.     

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.     

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.     

α-Amino acid derived enaminones and their application in the synthesis of N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates and other heterocycles

A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.     

Specific intramolecular aromatic CH insertion of diazosulfonamides

The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp³)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp²)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp²)?H and aliphatic 1,5- and 1,6-C(sp³)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp³)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp²)?H insertion.     

Microwave-assisted copper-catalyzed stereoselective ring expansion of three-membered heterocycles with α-diazo-β-dicarbonyl compounds

Microwave-assisted copper-catalyzed ring expansions of three-membered heterocycles with α-diazo-β-dicarbonyl compounds were investigated. Thiiranes generated 3-acyl-5,6-dihydro-1,4-oxathiines in the presence of copper sulfate and trans-3-acyl-5,6-dihydro-1,4-oxathiines as stereospecific products for 1,2-disubstituted cis-thiiranes through an intramolecular S_N2 process. Oxiranes gave rise to 2-acyl-5,6-dihydro-1,4-dioxines under the catalysis of copper hexafluoroacetylacetonate and cis-3-acyl-5,6-dihydro-1,4-dioxines as stereospecific products for 1,2-disubstituted cis-oxiranes via an intimate ion-pair mechanism. The current method provides a direct and simple strategy in efficient preparation of 3-acyl-5,6-dihydro-1,4-oxathiines and 2-acyl-5,6-dihydro-1,4-dioxines, important agents in medicinal and agricultural chemistry, from readily available thiiranes and oxiranes, respectively.     

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.