水中微量甲氰菊酯的分析

采用GC -MS定性 ,GC -FID(火焰离子化检测器)定量测定被嫌疑犯用甲氰菊酯污染的鱼塘水和蜂窝煤灰中的微量甲氰菊酯 ,样品经氯仿萃取、浓缩后 ,进行GC -MS测定 ;选定的色谱条件为5 %SE_30柱(2m×3.2mm) ,载体ChromosorbWAWDMCS,柱温250℃ ,气化室温度280℃ ,FID温度280℃ ,峰面积定量;该法快速、准确,RSD(n=6)为2.2 % ,回收率为95 %～98 %。     

气相-质谱法测定粮谷中恶草酮的残留量

 应用微量化学法和固相萃取技术 ,建立了粮谷中恶草酮残留量的气相 质谱 (GC MS)测定方法。用苯 正己烷 (体积比为 1∶1)萃取 ,中性氧化铝小柱净化。净化液用GC MS测定 ,采用外标法定量。恶草酮在大米中的回收率为 90 4%～ 115 .7% ,RSD为 2 %～ 6 % ,在玉米中的回收率为 81 3%～ 10 9 7% ,RSD为 4%～ 9% ,最低定量检出限为 0 0 0 5mg/kg。该法快速、灵敏、准确 ,各项技术指标均满足农药残留检测的要求。     

生物材料中克伦特罗的气相色谱-质谱法测定

建立了生物材料中克伦特罗 (clenbuterol)的气相色谱 -质谱测定方法 ;大白鼠喂食克伦特罗获得阳性生物材料 ,生物材料中克伦特罗经0.01mol/L盐酸溶液提取 ,乙醚脱脂净化 ,乙酸乙酯提取后蒸发至干 ,用乙醇溶解后加样到氧化铝柱上 ,用0.01mol/L盐酸溶液洗脱 ,蒸发至干后 ,用BSTFA(双三甲基硅烷基三氟乙酰胺 ) +1 % (φ)TMCS(三甲基氯硅烷 )衍生 ,采用GC -MS进行测定 ,外标法定量 ;试验表明 ,生物材料中添加0.056×10 -6～0.54×10 -6(w)含量水平的克伦特罗 ,方法回收率在89 %～107 % ,相对标准偏差为7.3 %～16 % ,线性相关系数r为0.998,克伦特罗的检出限为2.0×10-9(w)。     

茶叶中多种拟除虫菊酯类农药残留量的气相色谱-质谱测定

采用微量化学法和固相萃取技术，用丙酮/正己烷（1 1，V/V）萃取，活性炭和中性氧化铝小柱净化，用GC/MS可同时测定茶叶中6种拟除虫菊酯类农药的残留量。方法回收率在84.6%-115.1%之间，相对标准偏差为3%-7%，最低定量检出浓度在0.010-0.20mg/kg之间。该法快速、灵敏、准确，各项技术指标均衡足农残检测的要求。     

气相色谱-负化学电离质谱测定蔬菜中啶虫丙醚的残留量

建立以固相萃取净化和气相色谱-负化学质谱(GC/NCI/MS)技术快速测定蔬菜中啶虫丙醚残留量的方法。经乙腈提取,共提物中的基体杂质经PSA/SAX固相萃取柱去除,用负化学源质谱检测,灵敏度选择性高于气相色谱-电子轰击源质谱。目标农药的平均回收率为87.0%～91.0%,平均相对标准偏差为6.45%～6.80%(n=7),方法的检出限为1μg/kg。     

气相法测定葡萄中烯唑醇农药的残留量

 用气相法测定葡萄中的烯唑醇农药残留量。样品中的烯唑醇经丙酮提取 ,液 液分配和固相萃取小柱净化 ,用毛细管柱分离 ,气相 电子捕获检测器 (GC ECD)测定 ,外标法定量。方法的检测限为 0 0 1mg/kg ,回收率 >85 % ,相对标准偏差 <5 %。     

浓缩苹果汁中多种拟除虫菊酯类农药残留量的气相色谱-质谱测定方法

采用固相萃取技术,以丙酮和正己烷提取,C18小柱净化,用GC MS可同时测定浓缩苹果汁中4种拟除虫菊酯类农药的残留量。方法的回收率在96.5%～111.9%之间,相对标准偏差为1.7%～6.9%,最低检测浓度在0.02～0.10μg kg之间。     

串联双柱固相萃取-液相色谱-串联质谱法测定番茄酱中链霉素和双氢链霉素残留量

建立了同时测定番茄酱中链霉素和双氢链霉素残留量的串联双柱净化-液相色谱-串联质谱方法。样品中的残留物用磷酸盐缓冲液(pH 4)提取,经分散固相萃取净化和串联双柱固相萃取净化后,用极性色谱柱在梯度洗脱条件下分离待测物,采用正离子电喷雾离子源(ESI+)在多反应监测(MRM)扫描模式下进行测定,外标法定量。链霉素和双氢链霉素在0.01～0.2 mg/L质量浓度范围内线性关系良好,相关系数(r)大于0.999。链霉素和双氢链霉素的定量限均为0.02 mg/kg,回收率为71%～101%,相对标准偏差为2.3%～15%。该方法操作简便,净化效果好,灵敏,准确,适用于检测和分析番茄酱及其制品中链霉素和双氢链霉素残留量。     

环境中除草剂扑草净残留分析方法的研究

建立了高效液相色谱(HPLC)法测定环境中土壤、水和小麦中除草剂扑草净残留量的分析方法。采用丙酮超声提取,硅胶柱层析净化,测定土壤中扑草净残留量;水样直接用LC-18固相萃取小柱分离、净化和富集;采用超声提取,甲醇∶水=1∶1(V/V)为提取剂,LC-18固相萃取小柱分离、净化,测定小麦样品中扑草净的残留。结果表明:HPLC法检测扑草净的线性范围为0.5～16 mg.L-1,相关系数R2=0.9999,方法的检出限为0.0125 mg.L-1。土壤的加标回收率为88.2%～102.4%,相对标准偏差为6.3%～6.4%;水样的加标回收率为81.7%～102.5%,相对标准偏差为4.5%～4.6%;小麦的加标回收率为88.4%～101.7%,相对标准偏差为3.6%～5.5%。     

烟草中菊酯类农药残留量及其捕集转移率的测定

建立了一种同时测定烟草中5种拟除虫菊酯农药残留量及其捕集转移率的毛细管气相色谱法 ;样品经丙酮提取 ,石油醚萃取 ,硅酸镁载体净化 ,GC -ECD(63Ni)检测 ,外标法定量 ;实验表明 ,加标0.01×10-6～1.0×10-6 含量水平的功夫菊酯和溴氰菊酯 ,回收率为90%～96 % ,加标0.2×10-6～20×10-6 含量水平的甲氰菊酯、氯氰菊酯和氰戊菊酯 ,回收率为92 %～102 % ;同一样品中10次测定这5种菊酯类农药残留量的相对标准偏差为4.4 %～13%。     

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.