吹扫捕集-气相色谱-质谱法测定地表水中氯苯

采用吹扫捕集法富集地表水样中的氯苯,用气相色谱–质谱法进行测定。吹扫捕集流量为40 mL/min,吹扫时间为12 min,氯化钠加入量为2.5 g/(5 mL),以DB–624色谱柱进行分离。氯苯的质量浓度在0~40.0μg/L范围内与色谱峰面积呈良好的线性关系,相关系数r=0.999 4,检出限为0.07μg/L。加标回收率为93.4%~98.1%,测定结果的相对标准偏差小于3%(n=7)。该方法检出限低,精密度和准确度满足分析测试要求,适用于地表水中痕量氯苯的测定。     

毛细管气相色谱法测定鞋和箱包用胶粘剂中正己烷的含量

采用丙酮作为溶剂,选用19091N-213型毛细管色谱柱(30 m×0.32 mm i.d.,0.5μm)和氢火焰离子化检测器,以毛细管气相色谱法测定鞋和箱包用胶粘剂中正己烷含量。正己烷的浓度在0~1 000μg/mL与色谱峰面积成线性关系,线性回归方程为A=127 107c 383.26,相关系数r=0.999 1,检出限为0.003μg/mL,用该方法对胶粘剂样品进行测定,测定结果的相对标准偏差为2.8%~4.5%(n=5),加标回收率为96.4%~107.8%。     

金银花不同部位中绿原酸和木犀草苷含量的测定

利用HPLC法测定金银花不同部位中绿原酸和木犀草苷。采用ODS-C18色谱柱(250 mm×4.6 mm,5μm),以甲醇-水(0.03 mol/L磷酸)为流动相进行梯度洗脱,流速:1.0 mL/min,检测波长:350 nm,柱温:室温。绿原酸浓度在0~0.4 mg/mL内与峰面积呈良好线性关系(r2=0.999 6),回收率为101.9%~105.2%,相对标准偏差为3.18%(n=6)。木犀草苷浓度在0~0.1 mg/mL内与峰面积呈良好线性关系(r2=0.999 1),平均回收率为100.5%~104.0%,相对标准偏差为3.42%(n=6)。结果表明:金银花、芽等部位绿原酸和木犀草苷的含量较高。     

反相高效液相色谱法测定呋喃西林中有关物质

建立反相高效液相法测定呋喃西林含量和有关物质的方法。采用Phenomenex Synergi Max-RP C12色谱柱（250 mm×4.6 mm,4μm）为分离柱，以乙腈-水（30∶70）为流动相，流量为1.0 mL/min，检测波长为375 nm，色谱柱温度为30℃。在该色谱条件下，呋喃西林色谱峰与相邻杂质峰的分离度大于1.5，呋喃西林的质量浓度在1.04～104.0μg/mL范围内与色谱峰面积线性关系良好（r=0.999 2），检出限为0.3μg/mL。样品中单一杂质测定值的相对标准偏差为6.5%(n=6)，杂质总和测定值的相对标准偏差为4.6%(n=6)，平均加标回收率为100.4%～101.3%。该方法操作简单，专属性强，准确性好，可有助于控制呋喃西林的质量。     

蒸发光散射高效液相色谱法测定黄芪饮片中的黄芪甲苷含量

采用蒸发光散射高效液相色谱法测定黄芪饮片中黄芪甲苷的含量。黄芪饮片分别用甲醇和正丁醇提取,以Na OH溶液洗涤,蒸干,再用甲醇溶解,采用Agilent SB–C18柱(250 mm×4.6 mm,5μm)分离测定,流动相为乙腈–水(32∶68),流量为1.0 m L/min,漂移管温度为80℃。方法检出限为1.5μg/m L,黄芪甲苷溶液的质量浓度在2~12μg/m L范围内与色谱峰面积线性关系良好(r2=0.999 6),测定结果的相对标准偏差为0.65%(n=6),平均加标回收率为99.6%。该方法稳定可靠,可用于黄芪药材及其生物制品中黄芪甲苷含量的测定。     

液相色谱-质谱联用法测定人血浆中的阿莫西林

建立液相色谱–质谱联用法测定人血浆中的阿莫西林。在血浆样品中加入20μL 10μg/mL的阿莫西林-d4内标溶液,再经甲醇沉淀。色谱柱为Zorbax Eclipse XDB–C18(150 mm×2.1 mm,3.5μm),柱温为30℃,流动相为0.2%甲酸水溶液与0.2%甲酸甲醇溶液,采用梯度洗脱方式,流量为0.7 mL/min,进样体积为3μL;质谱采用电喷雾离子化方式和质谱多反应监测模式,检测离子为正离子。阿莫西林的质量浓度在0.05~10μg/mL范围内与其色谱峰面积呈良好的线性关系,相关系数为0.999 7,检出限为0.05μg/mL。测定结果的相对标准偏差小于3%(n=6),样品加标回收率为91.1%~97.3%。该方法操作简便,灵敏度高,专属性强,可用于测定人血浆中阿莫西林的含量。     

高效液相色谱法测定黄蜀葵花总黄酮胶囊中的金丝桃苷和槲皮素-3'-葡萄糖苷

建立高效液相色谱法测定黄蜀葵花总黄酮中金丝桃苷和槲皮素-3’-葡萄糖苷的含量。以乙腈–0.5%磷酸水溶液(22∶78)为流动相,流量为1.0 mL/min,柱温为30℃,检测波长为360 nm。金丝桃苷和槲皮素-3’-葡萄糖苷的质量浓度分别在12.232～73.392μg/mL,11.044～66.264μg/mL范围内与色谱峰面积呈良好的线性关系,相关系数均为0.999 9,检出限分别为200,180 ng/g。样品加标回收率分别为99.73%,100.78%,测定结果的相对标准偏差分别为0.86%,1.48%(n=6)。该方法操作简单、快速,结果准确,重现性好,可为黄蜀葵花总黄酮胶囊的质量控制提供依据。     

超快速液相色谱法测定甲基苯丙胺

建立了用超快速液相色谱(UFLC)仪测定甲基苯丙胺含量的方法。采用XR-ODS柱,流动相为0.05%磷酸-甲醇(85∶15),流速为0.4 mL/min,检测波长为215 nm。该法在1~5000μg/mL浓度范围内线性关系良好,r2=0.9998,日内与日间保留时间和峰面积的相对标准偏差均小于6%,样品的加标回收率为92.4%~116.7%,检出限为0.68μg/mL。该方法适用于甲基苯丙胺的定性定量分析。     

高效阴离子交换色谱-脉冲安培法测定生态养护抑菌凝胶中的褐藻寡糖

建立高效阴离子交换色谱–脉冲安培检测法测定生态养护抑菌凝胶中褐藻寡糖含量的方法。采用阴离子交换柱Carbo Pac PA10(250 mm×2 mm,3.5μm),以氢氧化钠、乙酸钠和水为洗脱液进行梯度洗脱,柱温为35℃,流量为0.8 mL/min。α-L-古罗糖醛酸单糖(PG)和β-D-甘露糖醛酸单糖(PM)的质量浓度分别在0.25～9.0μg/m L和0.18～8.4μg/mL范围内与色谱峰面积线性关系良好,线性相关系数分别为0.999 7和0.999 8,检出限分别为0.06,0.03μg/m L,定量限分别为0.20,0.10μg/mL。测定结果的相对标准偏差分别为1.11%,1.25%(n=6),加标回收率分别为101.03%和95.22%。该方法简便易行,灵敏度高,重现性好,适用于生态养护抑菌凝胶中褐藻寡糖的分析。     

加速溶剂萃取-气相色谱-串联质谱法测定党参中69种农药残留量

采用加速溶剂萃取-气相色谱-串联质谱法测定党参中69种农药残留量。样品以乙腈为溶剂经加速溶剂提取,提取液用Carb/NH2固相萃取小柱净化。在气相色谱分离中用VF-5MS柱为固定相,在质谱分析中采用多反应监测模式。69种农药在一定的质量浓度范围内与其峰面积呈线性关系,方法的测定下限(10S/N)在0.03~21.2μg·kg-1之间。在20,100,200μg·kg-1等3个浓度水平进行加标回收试验,回收率在63.8%~110%之间,测定值的相对标准偏差(n=6)在1.9%~13%之间。     

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.