高效液相色谱法同时测定三氯异氰脲酸(粉)中三聚氰酸和三聚氰胺的含量

建立高效液相色谱法同时测定三氯异氰脲酸(粉)中三聚氰酸和三聚氰胺含量的方法.采用HILIC Silica色谱柱(150 mm×4.6 mm,5 μm),以乙腈-10 mmol/L乙酸铵水溶液(9∶1)为流动相,用紫外检测器在213 nm波长处进行检测.三聚氰酸和三聚氰胺的浓度分别在9.22～92.2 μg/mL和10.92～109.2 μg/mL范围内与对应的峰面积呈良好的线性关系.三聚氰酸和三聚氰胺测定结果的相对标准偏差分别为0.3%、0.4%(n=6).在80%、100%、120%3个添加水平下三聚氰酸的平均回收率分别为117.41%、119.85%、114.40%.     

高效液相色谱法测定腐竹中的三聚氰胺

建立了腐竹中三聚氰胺的高效液相色谱检测方法.样品经0.1 mol/L的盐酸溶液提取,亚铁氰化钾和乙酸锌沉淀蛋白,以0.05 mol/L磷酸二氢钾溶液(pH 3.0)-乙腈为流动相,300-SCX离子交换色谱柱分离,二极管阵列检测器于波长240 nm处进行检测.该方法线性范围为0.1～5 μg/mL,检出限为2.0 mg/kg,测定结果的RSD为1.3%～2.5%(n=6),加标回收率为85.8%～92.1%,方法能够满足检测要求.     

超高速液相色谱测定奶粉中的三聚氰胺

使用超高速液相色谱仪(LCU),在LaChromUltra C18柱(50×2.0 mm i.d.,2 μm)上,以10 mol/L柠檬酸-10 mol/L辛烷磺酸钠/CH3CN为流动相,紫外240 nm检测,2.2 min内快速检测出奶粉中的三聚氰胺.结果表明,三聚氰胺浓度在0.25～100 μg/mL范围内线性关系良好(R2>0.999),平均回收率为87%～95%,保留时间的相对标准偏差为0.26%～0.38%,峰面积的相对标准偏差为0.91%～1.82%.该方法适用于大批量样品的常规分析.     

超高效液相色谱-串联质谱法测定水产品中三聚氰胺残留量

建立超高效液相色谱-串联质谱(UPLC-MS/MS)快速测定水产品中三聚氰胺残留的方法.采用ACQUITY UPLC BEH HILIC色谱柱(100 mm×2.1 mm, 1.7 μm),流动相为乙腈-0.5 mmol/L乙酸铵溶液(0.1%甲酸),流速为0.3 mL/min.采用电喷雾质谱检测,以正离子模式5 min完成质谱分析.实验结果表明,三聚氰胺在水产品中的检测限为0.05 mg/kg,在0.05～0.50 mg/kg添加水平时的加标回收率为63%～90%,测定结果的相对标准偏差均小于7.2%(n=6).     

水产品中氟苯尼考和氟苯尼考胺的高效液相色谱荧光法同时测定

建立了水产品中氟苯尼考和氟苯尼考胺同时检测的高效液相色谱荧光法,以乙腈-磷酸二氢钠溶液(0.01 mol/L,含0.005 mol/L十二烷基硫酸钠和0.10%三乙胺)(体积比2:3)为流动相,流速为0.6 mL/min,荧光检测激发波长为225 nm,发射波长为280 nm.本方法氟苯尼考在10～10 000 μg/L,氟苯尼考胺在2～2 000 μg/L范围内与峰面积呈线性相关,相关系数分别为1和0.999 9.当空白样晶中氟本尼考添加水平为20～200 μg/kg,氟苯尼考胺添加水平为4～50μg/kg时,该方法的回收率为79%～91%,相对标准偏差为3.66%～6.21%,检出限分别为5 μg/kg和1 μg/kg.     

反相高效液相色谱法测定人尿中利凡诺

建立了运用反相高效液相色谱法测定人尿中利凡诺的方法.采用Spherisorb C18色谱柱(250 mm×4.6 mm i.d.,5 μm);流动相: V(甲醇)∶V(乙腈)∶V(0.2 mol/L NH4Ac)=60∶37∶3;流速: 1.0 mL/min;柱温: 40 ℃;荧光检测器: 激发波长360 nm,发射波长500 nm.在5 ng/mL～1 μg/mL质量浓度范围内,呈现良好线性(r=0.9999),检出限为1 ng/mL.     

HPLC／UV法对银鲫肌肉组织中甲苯咪唑及其代谢产物残留的同时测定

建立了一种用高效液相色谱同时测定银鲫肌肉组织中甲苯咪唑(MBZ)及其代谢物氨基甲苯咪唑和羟基甲苯咪唑的方法.银鲫肌肉组织用乙酸乙酯提取,萃取物旋转蒸发至干后用1 mL二甲基甲酰胺-0.05 mol/L磷酸盐缓冲液(体积比3 ∶ 7)定容.色谱条件:Waters symmetry C18反相色谱柱(250 mm×4.6 mm,5 μm);流动相:乙腈-0.05 mol/L磷酸二氢铵溶液(体积比33 ∶ 67);流速:0.8 mL/min;检测波长为298 nm;检测温度为室温.在10 ～120 μg/kg添加水平,MBZ、MBZ-NH2、MBZ-OH的回收率分别为81% ～86%、71% ～75%、86% ～93%.MBZ的检出限为2 μg/kg,MBZ-OH和MBZ-NH2检出限均为3 μg/kg.     

超高效液相色谱-串联质谱法测定乳制品中三聚氰胺的残留量

建立一种用超高效液相色谱-电喷雾质谱联用技术测定乳制品中三聚氰胺残留量的方法.样品经含5%乙酸铅的三氯乙酸溶液提取,离心分离后经PCX-C18混合填料固相萃取柱净化.色谱分离采用Agilent ZORBAX-CN柱(250 mm×4.6 mm i.d.,5 μm),以10 mmol/L V(乙酸铵)∶V(乙腈)＝10∶90混合溶液为流动相.采用电喷雾离子源,正离子多反应监测(MRM)模式检测.该方法在1～1000 ng/mL范围内线性关系良好.在添加水平为10,30,45 μg/kg时,回收率在78.5%～92.6%之间,相对标准偏差在3.5%～8.6%之间,检出限为10 μg/kg.该方法适合于乳制品中三聚氰胺残留量的检测.     

鱼腥草中3种有效成分含量的测定

建立鱼腥草不同品种、不同部位绿原酸、芸香苷和槲皮素的测定方法. 以90% EtOH为溶剂, 采用索氏提取器提取, 利用HPLC测定3种活性成分的含量. 采用DiamonsilTMC18 (4.6 mm×150 mm, 5 μm)为色谱柱, 流动相分别为0.06 mol/L V(NaH2PO4)∶V(MeOH)＝7.3∶2.7、 V(MeOH)∶V(H2O)∶V(HAc)＝48∶50∶2, 流速为1 mL/min, 绿原酸检测波长为326 nm, 芸香苷和槲皮素为254 nm. 绿原酸、芸香苷、槲皮素的线性范围分别为4.6～30.7 μg/mL、 0.30～7.5 μg/mL、 0.034～0.85 μg/mL, 平均回收率和RSD分别为99.3%、 1.0%, 98.9%、 1.6%, 98.7%、 0.7%. 该方法可用于鱼腥草原料选择和制剂质量的控制.     

雪莲果中甲霜灵、异菌脲和除虫脲残留量的高效液相色谱测定方法

采用高效液相色谱法测定雪莲果中甲霜灵、异菌脲和除虫脲农药残留量.通过乙腈提取,固相萃取(SPE)净化,Hypersil Cold(4.6 mm i.d.×250 mm,5 μm)柱,V(乙腈)∶V(20 mM NH4Ac)=70∶30为流动相,柱温30℃,流速1.0mL/min进行分离,进样20 μL,2487双波长紫外检测器进行检测.添加回收率为78.4%～92.1%;RSD分别为3.6%～6.3%;甲霜灵,异菌脲和除虫脲检出限分别为0.05,0.04,0.02 μg/mL.     

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.