祛痘类化妆品中3种禁用除螨剂的高效液相色谱检测及质谱确证

建立了同时测定祛痘类化妆品中3种禁用除螨剂(克霉丹、灭螨猛和克螨特)的高效液相色谱分析方法及质谱确证方法。化妆品样品以甲醇为提取溶剂进行超声提取,提取液离心处理,取上清液经微孔滤膜过滤后测定。采用Kromasil C18(4.6 mm×250 mm,5μm)色谱柱进行分离,外标法定量。祛痘类化妆品中克霉丹、灭螨猛和克螨特的方法定量限分别为0.05,0.005和0.02 mg/kg,在低、中、高3个添加水平范围内平均回收率为80.7%~110.4%,相对标准偏差为2.3%~10%。采用高效液相色谱-串联质谱法进一步确证分析,电喷雾正离子模式电离,多反应监测模式检测。该方法适用于祛痘类化妆品的实际检验工作。     

超高效液相色谱-四极杆飞行时间质谱法测定饲料中9种雄性激素类药物

建立了超高效液相色谱-四极杆飞行时间质谱(UPLC-Q-TOF-MS)分析动物饲料中违禁添加的去氢睾酮(BOL)、表睾酮(epiAn)、氟甲睾酮(FT)、去氢甲睾酮(美雄酮)(MD)、甲睾酮(MT)、丙酸诺龙(NP)、诺龙(N)、丙酸睾酮(TP)和睾酮(T)9种药物的分析方法。样品经乙酸乙酯振荡提取,再用基质固相萃取方法净化处理后,采用UPLC-Q-TOF-MS分析检测。在电喷雾正离子模式和飞行时间模式下,输入各化合物的精确分子离子质量数得到相应的提取离子色谱图,以色谱峰面积进行定量分析。通过碰撞诱导解离模式(CID)得到各化合物碎片离子的精确质荷比,进一步对各化合物进行定性分析。各化合物的质量精确度均小于5×10-6,9种化合物在0～1000μg/L范围内均呈良好的线性关系,线性系数均大于0.99。除诺龙和去氢甲睾酮外,本方法对各药物的检出限(LOD)均低于6μg/L;去氢睾酮、表睾酮、氟甲睾酮、去氢甲睾酮(美雄酮)、甲睾酮、丙酸诺龙、诺龙、丙酸睾酮和睾酮的定量限(LOQ)分别为16,10,20,43,20,12,15,10g和16μg/kg。3个添加水平(LOQ,2LOQ,4LOQ)的回收实验表明,化合物的回收率在70.0%～99.7%范围内,相对标准偏差(RSD)均小于10%。本方法的定性准确度明显高于文献报道的方法,可用于饲料中的禁用雄性激素药物的测定。     

LC-MS/MS法同时测定祛痘类化妆品中林可霉素等20种禁用物质

建立了祛痘类化妆品中林可酰胺类、四环素类、硝基呋喃类抗生素及氯霉素、甲硝唑等20种禁用物质的LC-MS/MS同时测定法。样品以甲醇-1%甲酸溶液(1∶1,V/V)进行提取。色谱柱为ZORBAX SB-C18(2.1 mm×150 mm,3.5μm)。质谱仪采用电喷雾离子化源、正离子多反应监测模式。20种待测物在10~250 ng/m L范围内线性关系良好(r>0.995);检出限在0.01~0.2 mg/kg之间;在添加水平为1,3,10 mg/kg时,回收率为70.8%~93.8%,相对标准偏差(n=10)为2.4%~14%。方法可为祛痘类化妆品的日常监督提供技术支持。     

高效液相色谱-串联质谱法同时测定祛痘化妆品中的3种氯霉素类抗生素

建立了祛痘化妆品中氯霉素、甲砜霉素及氟苯尼考等3种氯霉素类抗生素的高效液相色谱-串联质谱检测方法。样品以甲醇为溶剂超声提取,提取液经高速离心及微孔滤膜过滤后,以XBridge Phenyl(2.1 mm×150 mm,3.5μm)色谱柱分离,进行电喷雾负离子多反应监测模式下的定性及定量分析。结果表明,氯霉素、甲砜霉素及氟苯尼考在各自线性范围内线性良好,定量限分别为5,20和10μg/kg。在低、中、高3个添加水平,3种氯霉素类抗生素的回收率为80.6%~117.4%,相对标准偏差(n=6)为4.6%~7.7%。方法能够为祛痘化妆品检验和生产质量控制提供科学依据及技术支持。     

液相色谱-串联质谱法同时测定化妆品中的16种激素

建立了同时测定化妆品中糖皮质激素、雌激素、雄激素、孕激素等各类共16种激素的液相色谱-串联质谱分析方法。不同形态的化妆品样品以甲醇为提取溶剂进行超声提取,样品提取液高速离心处理,上清液以Oasis HLB固相萃取柱净化,经Agilent ZORBAX XDB-C8(250mm×4.6mm,5μm)反相色谱柱分离后进行LC/MS/MS多反应监测模式下的定性及定量分析。其中糖皮质激素、雄激素和孕激素采用正离子扫描方式,雌激素采用负离子扫描方式进行质谱分析。16种激素的方法检出限为1~13μg/kg,在10~100μg/kg的3个添加水平范围内的平均回收率为72.8%~93.4%,相对标准偏差均小于10.2%。     

祛痘化妆品中苯海拉明的高效液相色谱检测及质谱确证

建立了祛痘化妆品中苯海拉明的高效液相色谱(HPLC)分析方法及液相色谱-串联质谱(LC-MS/MS)确证方法。水剂类和膏霜类祛痘化妆品样品分别采用适宜提取溶剂超声提取,提取液离心处理后,以HPLC测定。选用Waters XTerra MS C18色谱柱(250×4.6mm,5μm),以甲醇-10mmol/L碳酸氢铵缓冲溶液(体积比78∶22,氨水调节pH至10)为流动相,等度洗脱,流速1.0mL/min,检测波长218nm,外标法定量。阳性样品采用LC-MS/MS进行确证。苯海拉明的定量限为1.0mg/kg,在低、中、高添加水平的平均回收率为88.2%~105.0%,相对标准偏差在2.8%~7.9%之间。该方法简便、准确、灵敏度高,适用于祛痘化妆品中苯海拉明的测定。     

气相色谱-质谱法测定祛痘化妆品中4种硝基咪唑类化合物

建立了同时测定祛痘化妆品中4种硝基咪唑类化合物(甲硝唑、奥硝唑、洛硝唑和塞克硝唑)的气相色谱-质谱联用(GC-MS)分析方法。样品用碳酸钠溶液溶解后以乙酸乙酯提取,经浓缩和(或)正己烷除脂后,用N,O-双(三甲基硅烷基)乙酰胺衍生,样液经DB-5 MS(30 m×0.25 mm×0.25μm)毛细管色谱柱分离,GC-MS的选择离子监测(SIM)模式检测,以保留时间和特征离子比值定性,同位素内标法定量。结果表明,4种硝基咪唑类化合物在0.10~5.0 mg/L范围内线性关系良好,相关系数均不小于0.998;方法检出限(S/N=3)为0.05~0.10 mg/kg;在祛痘水和祛痘膏样品中进行3个水平的加标实验,平均回收率为85.6%~104%,相对标准偏差(RSD,n=6)为2.9%~6.5%。实际样品检测表明本方法准确可靠,适用于祛痘化妆品中硝基咪唑类化合物的同时测定。     

液相色谱-串联质谱结合谱库检索法同时测定猪组织中12种类固醇激素

建立了猪组织中12种类固醇类激素(炔诺酮、雄诺龙、醛固酮、去氢睾酮、达那唑、去氢甲睾酮、甲基睾丸酮、诺龙、孕酮、康力龙、睾酮和丙酸睾酮)多残留的液相色谱-四极杆/线性离子阱串联质谱(QTrap LC-MS/MS)的检测方法。组织样品经β-葡萄糖醛苷酶/芳基硫酸酯酶酶解提取,混合型强阳离子交换固相萃取小柱(MCX柱)净化后,以含0.1%(体积分数)甲酸的乙腈和水为流动相,经Venusil MP C18色谱柱(100 mm×2.1 mm, 3 μm)分离,按照多级反应监测(MRM)、信息相关采集(IDA)、增强子离子扫描(EPI),结合建立的12种类固醇类激素的标准谱图库检索的多步模式进行分析。结果表明,12种类固醇激素的线性范围为0.5～100.0 μg/L,线性相关性良好(r＞0.99);样品在5.0 μg/kg添加水平下的平均回收率为72.0%～98.1%,相对标准偏差为3.1%～12.5%;方法检出限(S/N=3)为0.2～0.5 μg/kg。实际样品检测结果表明,应用本方法可以实现对猪组织样本中类固醇类激素残留的定性定量分析,且具有灵敏、准确的特点。     

超高效液相色谱法测定美白、祛痘化妆品中4种禁用激素

建立了超高效液相色谱同时测定美白、祛痘化妆品中4种糖皮质激素氢化可的松、曲安奈德醋酸酯、氯倍他索丙酸酯、倍他米松双丙酸酯的方法。样品采用甲醇涡旋超声提取,色谱柱采用Waters ACQUITY UPLC BEH C18柱(100 mm×2.1 mm,1.7μm),流动相为乙腈–水溶液,梯度洗脱,流量为0.5 m L/min,用PDA检测器检测,检测波长为240 nm。方法检出限以3倍空白噪音计,氢化可的松、曲安奈德醋酸酯、氯倍他索丙酸酯、倍他米松双丙酸酯的检出浓度分别为0.12,0.18,0.30,0.30 mg/kg。在质量浓度为1.0~40.0 mg/L时,标准工作曲线相关系数r0.999 8,4种激素的回收率为85.3%~102.8%,测定结果的相对标准偏差为2.1%~5.0%(n=6)。该方法前处理简单,分离效果好,且灵敏度高,速度快,能满足美白、祛痘化妆品中4中糖皮质激素的检测需要。     

超高效液相色谱法同时测定化妆品中的15种激素

建立了采用超高效液相色谱同时测定化妆品中糖皮质激素、雌激素、雄激素、孕激素等共15种激素(曲安西龙、氢化可的松、泼尼松、可的松、甲基泼尼松龙、倍他米松、地塞米松、醋酸泼尼松龙、醋酸氢化可的松、雌三醇、雌二醇、雌酮、己烯雌酚、睾酮、孕酮)的分析方法。不同形态的化妆品样品均以甲醇为提取溶剂进行超声提取,经Oasis HLB固相萃取柱富集净化,以Waters ACQUITY UPLC BEH C18色谱柱(1.7 μm,2.1 mm×50 mm)分离,乙腈和水为流动相梯度洗脱,6 min 内完成了15种激素的分离及检测。在1～25 ng进样范围内,15种激素的工作曲线的线性相关系数r均高于0.9995。在低、中、高（2,10,20 mg/kg）3个添加水平下15种激素的平均回收率为88.2%～102.4%,相对标准偏差为1.6%～7.4%。     

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.