超高效液相色谱-串联质谱法快速测定口服液中非法添加的25种激素

建立了快速检测延缓衰老口服液中9种孕激素、7种雄激素、7种糖皮质激素及2种雌激素的超高效液相色谱-串联质谱(UPLC-MS/MS)方法。样品经1%乙酸-乙腈溶液、甲醇分步提取,浓缩至干后,用甲醇-水(1∶1)溶解残渣,Shim-pack XR-ODSⅡ色谱柱梯度分离,采用电喷雾正离子模式电离,基质匹配标准曲线定量。结果表明:25种化合物在0.5~50μg/L范围内呈良好的线性关系,相关系数均大于0.99,定量下限为0.099~0.492μg/kg,检出限为0.029~0.147μg/kg。在0.5,1.0,5.0μg/kg 3个加标水平下,各化合物的平均回收率为73.3%~122.2%,相对标准偏差(RSD)为5.1%~14.9%。该方法简便、快速、准确,适用于延缓衰老口服液中多种激素的同时、快速测定。     

QuEChERS/液相色谱-串联质谱法同时测定鱼肉中30种激素类及氯霉素类药物残留

建立了鱼肉中8种雌激素、5种雄激素、6种孕激素、8种糖皮质激素及3种氯霉素类药物多残留的QuEChERS/液相色谱-串联质谱(LC - MS/MS)同时测定方法.均质样品用水分散后加乙腈提取,经分散固相萃取净化后,采用ZORBAX Extend-C18色谱柱(100 mm ×2.1 mm,3.5 μm)分离,分别在电喷...     

猪血浆中33种类固醇激素的高效液相色谱-串联质谱测定

建立了猪血浆中雌激素、雄激素、皮质激素、孕激素以及部分违禁添加激素的高效液相色谱-串联质谱(HPLC-MS/MS)检测方法。以叔丁基甲醚为提取溶剂,涡旋振荡进行提取,采用Xselect-C18和Extend-C18(3.5μm,2.1 mm×100 mm)色谱柱进行目标物分离,外标法定量。结果表明,33种类固醇激素在其线性浓度范围内线性关系良好,相关系数均大于0.99;在3个不同浓度下的加标回收率为50.9%~119.5%,相对标准偏差为2.3%~9.8%,定量下限(LOQ)为0.05~40.00 ng/mL。采用所建立方法对北京某大型养猪场所采样品进行检测,共有10种激素被测出。该方法操作简单、灵敏度高、重现性好,可满足对猪血浆中类固醇激素的检测和验证要求。     

超高效液相色谱-高分辨率质谱法筛查化妆品中12种糖皮质激素

建立了超高效液相色谱-四极杆-静电场轨道阱质谱快速筛查和确证化妆品中可能添加的12种糖皮质激素的分析方法。样品经乙腈提取,用Acquity UPLC BEH C18柱(100 mm×2.1 mm,1.7μm)分离,以0.1%甲酸甲醇和0.1%甲酸水溶液为流动相进行梯度洗脱。以正离子全扫描模式得到糖皮质激素的精确质量数,与理论精确质量数对比,精确度偏差小于2×10-6。建立了筛查列表,并将12种糖皮质激素物质的二级质谱数据库加入确证条件中,实现了对12种糖皮质激素类物质的快速筛查。检出限为1~2μg/kg,定量下限为3~5μg/kg;加标水平为10,20,40μg/kg时,回收率为78.3%~112.5%,相对标准偏差(RSD)为1.0%~11.2%。该方法可作为化妆品中非法添加糖皮质激素成分的高通量筛选和确认检测方法。     

固相萃取-微乳液相色谱法对化妆品中8种激素的同时测定

建立了固相萃取-微乳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8种激素药物的新方法。化妆品样品用甲醇超声提取,经Cleanert ODS-SPE固相萃取柱纯化后,以Venusil ASB C8(T)(4.6 mm×200 mm,5μm,30 nm)为色谱柱,3.0%十二烷基硫酸钠(SDS)-6.6%正丁醇-0.8%正辛烷-89.6%水为流动相,检测波长为240 nm。结果表明,8种激素在15 min内达到基线分离,线性范围为0.5~30 mg/L,相关系数r均大于0.999 5。在低、中、高3种加标水平下,8种激素的平均回收率为82%~109%;相对标准偏差为1.5%~5.4%;检出限为0.04~0.07 ng。     

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%。     

动物肌肉组织中甾类同化激素多组分残留的液相色谱-质谱检测方法

建立了不同动物肌肉中甾类同化激素(表睾酮、丙酸睾酮、19-去甲基睾酮、甲基睾酮、孕酮、甲羟孕酮、雌二醇、雌三醇、炔雌醇、雌酮)多残留量的LC/MS/MS确证方法。样品加醋酸缓冲溶液均质,加酶溶液酶解后,再加甲醇超声提取,用叔丁基甲醚液-液萃取至少2次,之后经反相固相萃取柱净化,以乙腈-水为流动相,经C18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。其中雄激素,孕激素采用正离子扫描,雌激素则采用负离子扫描。17beta-NT、MTS、ETS、MED、PG、PTS、EST、17beta-ES、EES和ESN的定量检出限为0.5~1.0μg/kg。在1.0μg/kg的定量检出限添加水平,上述10种激素的平均回收率为55%~77%;相对标准偏差为7.1%~35%。可实现样本灵敏、准确的定性定量分析。     

超高效液相色谱-串联质谱法测定湿疹膏中67种激素EI北大核心CSCD

建立了湿疹膏中67种激素的超高效液相色谱-串联质谱(UPLC-MS/MS)检测方法。样品先经饱和NaCl溶液分散,再经乙酸乙酯提取,QuEChERS净化后,UPLC-MS/MS检测,选择Waters AcQuityBEH C18色谱柱(1.7μm, 2.1 mm×100 mm),多反应监测模式扫描。67种激素在相应的浓度范围内,线性关系良好,相关系数均大于0.995,在3个不同浓度加标水平下,平均回收率为71.8%~115.9%,相对标准偏差(RSD)为1.7%~12.5%,定量限(LOQ)范围为0.15~1.00μg/kg,该方法能够满足湿疹膏中67种激素的检测需求。     

液相色谱-串联质谱法测定化妆品中15种性激素

采用液相色谱-串联质谱法(LG-MS/MS)测定了化妆品(膏霜、乳液或水剂)中15种性激素的含量。样品(0.20g)与饱和氯化钠溶液(2mL)混匀分散,用乙腈(每次2mL)提取2次。合并提取液,加入200g·L~(-1)亚铁氰化钾溶液和200g·L~(-1)乙酸锌溶液各0.2mL,混匀使大分子物质沉淀,离心后取上清液,加水定容至10mL。按不同的程序分别对雌激素、雄激素和孕激素进行梯度洗脱。质谱测定中对雌激素采用负离子模式,雄激素和孕激素采用正离子模式。15种性激素的质量浓度均在8.0~800μg·L~(-1)内与其对应的峰面积呈线性关系,方法的检出限(3S/N)为0.05~0.4mg·kg~(-1)。经多批实样分析,所得测定值的相对标准偏差(n=6)为0.90%~4.3%,加标回收率为80.3%~121%。     

UFLC-IT-TOF-MS分析婴幼儿配方乳粉中的12种雌孕激素

建立了婴幼儿配方乳粉中12种雌孕激素的超快速液相色谱-离子阱-飞行时间串联质谱(UFLCIT-TOF-MS)测定方法。乳粉样品在37℃水溶解、酶解后,经乙腈提取,HLB柱净化,Shim-pack XRODSⅡ和HSS T3色谱柱梯度分离,采用电喷雾离子源(ESI)负离子模式对雌激素进行分析,正离子模式对孕激素进行分析。12种雌孕激素在1.0~200μg/L范围内线性关系均良好(r~2>0.998),平均回收率为79.9%~110.4%,相对标准偏差为2.8%~8.0%,检出限和定量下限分别为0.3~0.6μg/kg及0.9~1.8μg/kg。实验考察了12种雌孕激素精确质量数的测定能力并验证了雌酮的三级裂解。     

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.