加速溶剂萃取/气相色谱-三重四极杆串联质谱法测定纺织品中24种多环芳烃

建立了加速溶剂萃取/气相色谱-三重四极杆串联质谱(ASE/GC-MS/MS)同时测定纺织品中24种多环芳烃(PAHs)的方法。样品经丙酮加速溶剂萃取,旋蒸浓缩后采用DB-35色谱柱程序升温分离,选择多反应监测模式(MRM)采集,外标法定量。结果表明,在一定浓度范围内多环芳烃的峰面积与质量浓度呈良好的线性关系,相关系数(r~2)均大于0.994,方法检出限为0.000 3~0.03 mg/kg,方法定量下限为0.001~0.10 mg/kg,加标回收率为80.3%~103%,相对标准偏差(RSD)为1.3%~9.2%。该方法灵敏、准确可靠,能满足纺织品中24种多环芳烃的测试要求。     

加速溶剂萃取和凝胶渗透色谱净化GC–MS法测定烟熏腊肉中16种多环芳烃

采用ASE萃取、GPC净化和浓缩,建立GC–MS法快速检测烟熏腊肉中16种多环芳烃(PAHs)的分析方法。将烟熏腊肉与硅藻土充分混合后,放到萃取池中加速溶剂萃取,在优化仪器条件下测定,16种PAHs的线性范围为0.1~4 ng/m L,线性相关系数r为0.985 3~0.999 9。方法检出限在0.172~0.233μg/kg之间,加标回收率为60.3%~93.2%,测定结果的相对标准偏差为4.06%~11.60%(n=6)。该方法检测快速,准确度高,重现性好,适合于烟熏腊肉中16种PAHs的同时测定。     

四通道色谱分离仪净化/气相色谱-质谱法测定烟叶中的多环芳烃

建立了同时检测新鲜烟叶中16种多环芳烃(PAHs)的四通道色谱分离仪净化/气相色谱-质谱(GC-MS)分析方法。样品经二氯甲烷索氏提取,四通道色谱分离仪净化,GC-MS选择离子监测模式(SIM)测定和外标法定量,重点考察了新鲜烟叶提取液的分离净化条件。结果表明:16种PAHs类化合物在10~1 000μg/kg范围内定量离子的峰面积与质量浓度呈较好的线性关系(r0.99)。仪器检出限(LOD)为0.35~1.75μg/kg,方法检出限(MDLs)为1.01~2.87μg/kg。在10,50,200μg/kg 3个浓度水平下的加标回收率为81.0%~107.8%,相对标准偏差(RSD,n=6)为2.7%~8.0%。该方法简便、快捷、可操作性强、应用范围广,适合于烟草等作物中PAHs类化合物的分析检测。     

QuEChERS/气相色谱质谱法同时测定膨化食品中多环芳烃类物质

建立了同时测定膨化食品中12种多环芳烃(PAHs)的Qu EChERS/气相色谱三重四极杆质谱(GC-MS/MS)的方法。称取2 g(精确至0.01 g)样品,加入10 mL正己烷提取15 min,采用500 mg乙二胺-N-丙基硅烷化硅胶(PAS)和500 mg C18粉末进行净化,净化后进行GC-MS/MS分析测定。实验结果表明,12种多环芳烃在气相色谱中的分离度良好,在1~1000 ng/mL的浓度范围内线性关系良好。加标回收率测定范围为49%~130%,RSD在1.0%~10%(n=7)之间。检出限在0.20~0.66μg/kg之间,定量限在0.66~2.20μg/kg之间。该方法数据可靠、操作简单快捷、灵敏度高,适合大批量样品中PAHs的测定。     

固相微萃取/气相色谱-质谱联用法测定沥青基防水涂料中18种多环芳烃的迁移量

建立了固相微萃取/气相色谱-质谱(SPME/GC-MS)测定沥青基防水涂料中18种多环芳烃(PAHs)迁移量的方法。研究了萃取涂层、萃取时间、搅拌速度及萃取温度对萃取效果的影响。在优化条件下,18种PAHs在1~100μg/L范围内呈良好的线性关系,相关系数(r)为0.992 8~0.998 9,检出限为0.03~0.09μg/L;在1、10、100μg/L加标水平下的平均回收率为71%~94%,相对标准偏差(RSD,n=6)为2.8%~8.6%。对5份沥青基防水涂料进行迁移实验,发现迁移液中均检出PAHs,且主要为四环以下的PAHs。实验表明该方法适应于沥青基防水涂料中18种PAHs的迁移量检测。     

快速溶剂萃取-气相色谱-三重四极杆质谱法测定沉积物中的酞酸酯

建立了快速溶剂萃取(ASE)-气相色谱-三重四极杆质谱(GC-MS/MS)测定沉积物中酞酸酯的方法。样品用二氯甲烷-丙酮(体积比为1:1)混合溶剂在100 ℃、103.4 MPa (1500 psi)条件下经快速溶剂萃取、以5 mL/min的速率经凝胶渗透色谱(GPC)净化去除大分子干扰物后,采用GC-MS/MS分析测定。采用内标法定量,17种酞酸酯的检出限为0.05～0.40 μg/kg;回收率为50.5%～107.9%,相对标准偏差为3.5%～13.9%。采用替代物基体加入法对方法的性能进行了验证,3种替代物的回收率为65.3%～95.8%。该方法快速、灵敏度高,能同时准确定性定量测定17种酞酸酯。     

快速溶剂萃取-气相色谱-串联质谱法分析海洋沉积物中16种多环芳烃

建立了快速溶剂萃取（ASE）-气相色谱-串联质谱（GC-MS/MS）分析海洋沉积物中16种多环芳烃（PAHs）的分析方法。样品由正己烷-丙酮（1∶1,v/v）溶液萃取,经无水硫酸钠脱水、氮吹浓缩后,采用硅胶固相萃取小柱进行净化,然后经HP-5MS色谱柱（30 m×0.25 mm×0.25 μm）分离,在电子轰击电离源下以多反应监测（MRM）模式进行检测,内标法定量。分析结果表明,16种PAHs在0.01~1.00 mg/L范围内线性关系良好,相关系数（R）大于0.997;目标物的加标回收率为75.8%~97.8%;日内与日间精密度（RSD）均小于10%。当取样量为20.0 g时,16种PAHs的方法检出限为0.048~0.234 μg/kg。该法快速、准确、稳定,能够满足海洋沉积物中痕量PAHs的测定。     

加速溶剂提取-高效液相色谱法测定甘草中甘草酸的含量

采用加速溶剂提取法(ASE)提取甘草中有效成分甘草酸,高效液相色谱(HPLC)法测定其含量,探索ASE法提取甘草酸的最佳工艺条件,寻找一种快速、高效测定甘草中甘草酸含量的新方法.结果表明,ASE法提取甘草酸的最佳工艺条件为:提取温度为60℃,提取3次,每次静态提取时间为15 min,提取率高达2.15%.ASE-HPLC法是一种准确、快速测定甘草酸含量的新方法.     

加速溶剂萃取-固相萃取净化-气相色谱/质谱法测定沉积物中多氯联苯和多环芳烃

建立了加速溶剂萃取-固相萃取净化-气相色谱/三重四极杆串联质谱联用(ASE-SPE-GC-QqQ-MS/MS)法同时测定沉积物中28种多氯联苯(PCBs)和16种多环芳烃(PAHs)。对萃取、净化及仪器分析条件进行了优化。优化条件为:ASE萃取温度90℃,萃取时间6 min;净化小柱为硅胶-Florisil固相复合柱(填料自下而上为弗罗里硅土、0.7 g活化硅胶、1 g无水硫酸钠);洗脱溶液为丙酮-正己烷(1∶19,V/V)混合溶液,洗脱速率为0.6 mL/min。PCBs和PAHs在2～500μg/L和5～1000μg/L浓度范围内的线性相关系数(R2)分别为0.9987～0.9999和0.9939～0.9999;PCBs和PAHs方法检出限分别为0.001～0.08 ng/g和0.07～0.45 ng/g;定量限为0.003～0.25 ng/g和0.24～1.67 ng/g;实际样品平均加标回收率为95.6%～125.7%和70.4%～124.7%;方法相对标准偏差(n=6)为0.7%～6.4%和1.1%～12.8%。运用本方法对滇池入湖河口表层沉积物样品进行测定,该区域PCBs单体浓度为n.d.(未检出)～0.13 ng/g,PAHs单体浓度为0.79～131.12 ng/g。     

分散固相萃取-气相色谱-串联质谱法测定蔬菜中多环芳烃及卤代多环芳烃

建立了同时检测蔬菜中16种多环芳烃(PAHs)和11种卤代多环芳烃(X-PAHs)污染水平的分散固相萃取-气相色谱-串联质谱(GC-MS/MS)分析方法。样品中的多环芳烃和卤代多环芳烃经正己烷提取,N-丙基乙二胺吸附剂(PSA)和十八烷基键合硅胶吸附剂(C18)分散固相萃取净化剂净化,气相色谱-串联质谱方法测定,外标法定量。16种PAHs和11种X-PAHs在50,100和200μg/kg添加浓度下的回收率为74.7%～115.1%,相对标准偏差为1.6%～15.3%,方法检出限为0.03～7.4μg/kg。     

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.