超临界萃取蝼蛄脂肪酸成分及其气相色谱-质谱分析

采用超临界CO2萃取蝼蛄总脂肪酸,对影响萃取效果的各个因素应用正交设计试验,优化了各萃取参数.各个因素的影响顺序为压力＞温度＞时间＞流量.萃取的优化条件为压力35 MPa,温度50℃,时间1 h,流量45 kg/h.运用该萃取条件改善了萃取物的物理性状,脂肪酸的纯度提高,总脂肪酸的含量可达83.29%;而采用常规的有机溶剂提取法,脂肪酸的纯度仅为60%左右.甲酯化采用气相色谱-质谱分析技术对其中的16个成分进行了鉴定,并测定了相对含量,其中主要有油酸甲酯(30.40%)、十六烷酸甲酯(14.19%)、9,12-十八碳二烯酸甲酯(11.99%)、油酸乙酯(11.75%)、9-十六碳烯酸甲酯(7.77%)、十六烷酸乙酯(5.97%)、9,12-十八碳二烯酸乙酯(4.53%)及9-十六碳烯酸乙酯(2.87%)等.     

N, N, N′, N′-四丁基丙二酰胺萃取Pr3+的研究

利用丙二酸二乙酯与二正丁胺反应高收率的制备了N，N，N′，N′-四丁基丙二酰胺(TBMA)萃取剂。研究了硝酸浓度、硝酸锂浓度、萃取剂浓度以及温度等对萃取Pr(Ⅲ)分配比的影响，确定了萃合物的组成，得到了不同稀释剂中萃取反应的热力学数据。结合红外光谱和摩尔电导数据初步推断了萃合物的结构。     

氢氧化铯作用下α-烷基(或α,α-二烷基)丙二酸二乙酯的合成

以DMF为溶剂,卤代烃(RX)与丙二酸二乙酯(1)在氢氧化铯(CsOH)催化下合成了α-烷基丙二酸二乙酯(2)和α,α-二烷基丙二酸二乙酯(3). 当r[n(RX) ∶ n(CsOH) ∶ n(1)]=1.0 ∶ 1.0 ∶ 1.0时,2为主要产物;当r=2.2 ∶ 2.0 ∶ 1.0时,3为主要产物.化合物的结构经1H NMR和MS表征.     

顶空固相微萃取气相色谱-质谱单离子监测法测定水中的多种己二酸酯

采用顶空固相微萃取和气相色谱 质谱单离子监测技术,以己二酸二(1 丁基戊基)酯为内标,对水中的己二酸二乙酯、己二酸二异丁酯、己二酸二丁酯、己二酸二(2 丁氧基乙基)酯、己二酸二(乙基己基)酯进行了测定,考察了盐效应、萃取温度、萃取时间和热解吸时间等因素对方法灵敏度的影响。该方法对5种己二酸酯的检测限量为0.0220～5.49μg L,回收率为86.9%～102.0%,相对标准偏差为1.5%～7.3%。     

固相微萃取气相色谱法测定水相中邻苯二甲酸二酯

 采用m(聚硅氧烷 (OV 1) )∶m (富勒烯聚二甲基硅氧烷 (PSO C60 ) ) =4∶1的混合固定相自制萃取头 ,利用顶空固相微萃取与气相色谱联用技术 (HS SPME GC)分析了水中 5种邻苯二甲酸二酯。考察了萃取温度、离子强度、吸附和热解吸时间等因素对该方法灵敏度的影响。结果表明该萃取头萃取选择性优于商用PDMS萃取头。方法的检出限为 0 331ng/L～ 12 5 μg/L ;除邻苯二甲酸二正壬酯外 ,相对标准偏差均在 12 %以下。     

固相微萃取气相色谱法测定水相中邻苯二甲酸二酯

采用m(聚硅氧烷 (OV 1) )∶m (富勒烯聚二甲基硅氧烷 (PSO C60 ) ) =4∶1的混合固定相自制萃取头 ,利用顶空固相微萃取与气相色谱联用技术 (HS SPME GC)分析了水中 5种邻苯二甲酸二酯。考察了萃取温度、离子强度、吸附和热解吸时间等因素对该方法灵敏度的影响。结果表明该萃取头萃取选择性优于商用PDMS萃取头。方法的检出限为 0 331ng/L～ 12 5 μg/L ;除邻苯二甲酸二正壬酯外 ,相对标准偏差均在 12 %以下     

单滴液相微萃取-高效液相色谱法测定水中二甲戊乐灵农药残留

应用单滴液相微萃取(SD-LPME)技术建立了水体中二甲戊乐灵农药的高效液相色谱(HPLC)分析方法.研究了不同的萃取条件(萃取剂、体积、萃取时间、搅拌速度、温度等)及测定条件对检测二甲戊乐灵的影响,确定了最佳萃取条件:环己烷作萃取剂,萃取剂体积5 μL,液滴体积2 μL,搅拌速度350 r/min,35 ℃条件下萃取35 min.应用此方法测定了自来水和太湖水样中的二甲戊乐灵农药残留,相对标准偏差(RSD)在2 5%～3.4%(n=6)之间;回收率为88.0%～99.8%.     

N,N′-二(十二烷基)乙二胺二乙酸萃取分离铜

研究了N,N′-二(十二烷基)乙二胺二乙酸的氯仿溶液对铜的萃取行为,考察了初始水相酸度、萃取剂浓度及温度对Cu(Ⅱ)萃取率的影响. 结果表明,在pH≥6条件下对Cu(Ⅱ)有很高的萃取率,且在一定范围内随萃取剂浓度增大和温度升高萃取率均增大;用摩尔比法和电导法测得萃合物中Cu2+与萃取剂的摩尔比为1∶1;控制pH=6能使Cu(Ⅱ)与常见过渡金属离子Fe(Ⅱ)、Co(Ⅱ)、Ni(Ⅱ)、 Zn(Ⅱ)、Mn(Ⅱ)得到分离.     

超声波辅助分散液液微萃取-气相色谱法测定水中的邻苯二甲酸二乙酯和菲

建立了超声波辅助-低密度萃取剂分散液液微萃取(LDS-USA-DLLME)-气相色谱法测定水中邻苯二甲酸二乙酯(DEP)和菲(Phe)的方法。采用低密度溶剂(甲苯)为萃取剂,超声波为分散剂处理水样,并讨论了萃取剂种类和体积、超声温度和时间、冰浴时间和盐效应等重要因素对回收率的影响。在最优萃取条件下,DEP和菲在0.1~100μg·L~(-1)范围内具有良好的线性,相对标准偏差在3.5%~7.8%之间,检出限为0.006和0.010μg·L~(-1)。对实际水样进行加标实验,回收率在81.9%~100.6%之间。该方法具有高效、简便、廉价、环境友好等优点,能够成功分析水中的DEP和菲。     

气相色谱-质谱法测定豉香型白酒中β-苯乙醇及3种二元羧酸的二乙酯

用2-乙基正丁酸为内标物,提出用气相色谱-质谱联用全扫描法测定豉香型白酒中β-苯乙醇和在特定保留时间窗内选择性离子法测定庚二酸二乙酯、辛二酸二乙酯和壬二酸二乙酯含量。此方法对β-苯乙醇的检出限（S／N=3）为5．0mg·L^-1,对其他3种二元羧酸的二乙酯的检出限均为0．01mg·L^-1,测得方法的回收率在90％～110％之间,相对标准偏差（n=10）均小于9％。     

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.     

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.     

Synthesis of pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles by Curtius reaction in Morita-Baylis-Hillman derivatives

Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.     

正丁胺对激光染料荧光谱影响的研究

用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.     

Cu0-catalysed 1,3-dipolar cycloadditions of α-amino acid derived N,N-cyclic azomethine imines to ynones

A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu⁰ as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than Cu^I in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).     

Synthesis and antioxidative/anti-inflammatory activity of novel fullerene–polyamine conjugates

(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C₆₀, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.