多重吸附同步净化-气相色谱-质谱联用法测定水产品中痕量的二甲苯麝香和酮麝香

为了考察水产品中二甲苯麝香和酮麝香的残留量,建立了水产品中痕量二甲苯麝香和酮麝香测定的多重吸附同步净化（MASP）-气相色谱-质谱联用法（GC-MS）。以乙腈高速匀浆提取样品,应用MASP方法对样品同时进行提取、盐析和净化,并采用GC-MS在选择离子监测（SIM）模式下测定水产品中的痕量二甲苯麝香和酮麝香,以基质匹配标准溶液外标法定量。选用DB-5 MS石英毛细管柱（30 m×0.25 mm×0.25 μm）,采用电子轰击电离源,二甲苯麝香的选择监测离子为m/z 282、297、265,酮麝香为m/z 279、294、191。结果表明：在优化条件下,二甲苯麝香和酮麝香在1~100 μg/kg范围内线性良好,相关系数不低于0.999,检出限（S/N=3）为0.30 μg/kg。明虾、花蛤和鳗鱼空白样品中1.0、2.0、10.0 μg/kg 3个添加水平下二甲苯麝香和酮麝香的加标回收率为79%~104%,相对标准偏差（RSD）为1.6%~13.3%。本方法具有操作简便、快速、准确的特点,可用于水产品中痕量二甲苯麝香和酮麝香的日常检测。     

固相萃取-气相色谱-质谱法测定进口海产品中11种合成麝香

建立了固相萃取-气相色谱-质谱法同时测定进口海产品中11种合成麝香（开司米木、萨利麝香、粉檀麝香、葵子麝香、特斯拉、佳乐麝香、二甲苯麝香、吐纳麝香、伞花麝香、西藏麝香和麝香酮）。样品经正己烷提取,弗罗里硅土固相萃取柱净化,内标法定量。目标物在0.001~0.1 mg/L内呈良好的线性相关,相关系数（r²）均大于0.990,方法检出限（信噪比（S/N）>3）为0.35~2.08μg/kg,定量限（S/N>10）为1.18~5.00μg/kg。分别在空白基质中添加低、中、高3个水平的标准品进行回收试验,平均回收率为83.1%~117%,相对标准偏差（RSD,n=6）为5.1%~8.5%。利用该方法对2017年上海口岸进口的30个海产品进行了筛查,发现佳乐麝香在93.3%的被测样品中均有检出,含量最高达3.82μg/kg。葵子麝香和伞花麝香也是检出较多的麝香品种,含量最高分别可达15.4μg/kg和10.5μg/kg。该方法特异性强,灵敏度高,适用于海产品中多种合成麝香残留物的筛查和确证。     

气相色谱串联质谱法测定个人护理品中九种合成麝香

建立了气相色谱串联质谱技术测定沐浴露、洗发露、洗衣液、洗洁精、洗手液、花露水、洗衣粉和香水8类个人护理品中9种合成麝香(SMs)检测方法。样品采用甲醇稀释,气相色谱串联质谱测定,内标法定量(内标物质为荧蒽-D10)。9种合成麝香的线性范围为0.5～100μg/L,相关系数均大于0.99,检出限为0.05～0.10μg/L。9种合成麝香的平均回收率为80.6%～125.3%,标准偏差为3.1%～9.6%。该方法利用GC-MS/MS的多反应监测模式灵敏度高,有效排除干扰。用本法,在146份样品中检出99份添加佳乐麝香和吐纳麝香,检出质量分数分别为36.1～40253.2 mg/kg和1.7～8772.4 mg/kg。     

麝香酮合成的新方法

麝香酮合成的新方法陈望忠焦克芳（北京军事医学科学院毒物药物研究所１００８５０）麝香酮（ｍｕｓｃｏｎｅ，３－ｍｅｔｈｙｌｃｙｃｌｏｐｅｎｔａｄｅｃａｎｏｎｅ）的人工合成是半个多世纪以来许多有机化学家十分关注的课题，文献上报道了许多的合成路线和方法［１］...     

气相色谱-负化学源-三重四极杆质谱法测定化妆品中的硝基麝香类化合物

建立了一种用于不同化妆品中5种硝基麝香含量的气相色谱-负化学离子源三重四极杆质谱联用(GC-MS/MS)检测方法。采用丙酮/正己烷混合溶液超声提取化妆品中的硝基麝香,将提取液浓缩,以CNWBOND Si固相萃取柱净化。再由GC-MS/MS检测,氘代二甲苯麝香内标法定量。该方法对化妆品中5种硝基麝香的加标回收率为85.81%～103.77%,相对标准偏差(RSD)不大于5.32%,灵敏度高,定量限为50.0～500 ng/kg;选择性好,能有效消除复杂基体干扰。可作为常见化妆品中硝基麝香类化合物含量检测的确证方法。     

固相微萃取-气相色谱法测定醒脑静注射剂中的麝香酮

中药制剂醒脑静注射剂中的麝香酮含量较低,采用水蒸气蒸馏法需要长时间的提取富集才能进行含量测定.本文采用固相微萃取-气相色谱法（SPME-GC）对醒脑静注射剂中的麝香酮含量进行测定,集样品采集、萃取、浓缩、进样和分析于一体,完成测定的整个过程仅需十几分钟,操作简单,测定结果准确可靠.     

分散固相萃取-气相色谱-质谱联用法测定水产品中的痕量酮麝香

建立了水产品中痕量酮麝香测定的分散固相萃取-气相色谱-质谱联用法(GC-MS)。目标化合物经1%乙酸-乙腈高速匀浆提取,以N-丙基乙二胺(PSA)、C₁₈和石墨化碳(GCB)混合物为分散剂对其进行净化,采用GC-MS在选择离子监测模式下测定,外标法定量,并应用正交试验对前处理条件进行优化,以及对酮麝香的裂解机制进行探讨。在优化条件下,方法在1～50 μg/L范围内线性关系良好,相关系数不低于0.999,检出限(S/N=3)为0.30 μg/kg。对于明虾和罗非鱼空白样品,在1.0、2.0、10.0 μg/kg 3个水平下的加标回收率为91.8%～110.6%,相对标准偏差(RSD)为2.6%～8.4%。该方法操作简便、快速、准确,可用于水产品中痕量酮麝香的日常检验。     

固相萃取GC-MS法测定通栓醒脑注射液中冰片和麝香酮的含量

建立通栓醒脑注射液中冰片和麝香酮含量的测定方法。采用固相萃取法处理样品，用GC-MS法同时分离测定冰片和麝香酮的含量。冰片和麝香酮的回收率和相对标准偏差分别为97．8％～104．8％，2．72％和97．6％～105．4％，3．86％。本法快速准确，可用于通栓醒脑注射液的质量控制。     

固相萃取-气相色谱-串接质谱法测定化妆品中的人工合成硝基麝香类化合物

建立了一种用于不同化妆品中5种硝基麝香含量的气相色谱-三重四极杆串联质谱联用检测方法。化妆品中的硝基麝香通过丙酮/正己烷混合液超声提取,提取液经过浓缩,以CNWBOND Si固相萃取柱净化。再由气相色谱-三重四极杆质谱联用仪检测,氘代二甲苯麝香内标法定量。该方法对化妆品中5种硝基麝香的加标回收率在85.81%～104.92%之间,相对标准偏差(RSD)不大于5.75%,检测限分别达到2.0～10.0μg/kg。方法选择性好,能有效消除复杂基体干扰,可作为常见化妆品中硝基麝香类化合物含量检测的确证方法。     

氘代同位素内标气相色谱-质谱法测定食用香精中的二甲苯麝香

建立了氘代同位素内标气相色谱-质谱测定食用香精中二甲苯麝香含量的分析方法。采用漩涡混合器混合样品,使样品基质均匀分散于萃取溶剂中,再使用超声波提取目标物,探讨了萃取溶剂种类、溶剂用量及超声时间等因素对目标物萃取效率的影响;之后使用GC-MS选择离子监测模式检测,氘代同位素内标法定量,分析了不同极性色谱柱对目标物分离的影响,确定了较佳的特征离子及其丰度比。在优化实验条件下,二甲苯麝香在0.025～0.5 mg/L范围内具有良好的线性关系,相关系数(r2)为0.999 6,平均回收率为94%～116%,相对标准偏差(RSD)为4.2%～6.5%,检出限为0.11 mg/kg,定量下限为0.38 mg/kg。该方法简便、快速、灵敏、准确,适合于食用香精中二甲苯麝香含量的测定。     

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%.     

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.     

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.     

N-Heterocyclic carbene-palladacyclic complexes: synthesis,characterization and their applications in the C-N coupling and α-arylation of ketones using aryl chlorides

N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).     

Iodine-mediated oxidative Pictet-Spengler reaction using terminal alkyne as the 2-oxoaldehyde surrogate for the synthesis of 1-aroyl-β-carbolines and fused-nitrogen heterocycles

An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y₁ and Y₂. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.     

Facile synthesis of bicyclic 1-arylpyrazol-5-ones

In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.     

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.