亚临界水萃取及液相色谱-串联质谱法检测猪肉中β-受体激动剂与氯霉素残留

建立了亚临界水萃取及液相色谱-串联质谱法(LC-MS/MS)检测猪肉中β-受体激动剂和氯霉素的方法。样品酶解后,经亚临界水萃取,C18粉未净化,目标物经Agilent XDB-C18柱(4.6 mm×50 mm,1.8μm)分离,采用液相色谱-串联质谱法多反应监测(MRM)模式检测,基质匹配溶液内标法定量。优化条件下,沙丁胺醇和莱克多巴胺在1.0～32.0μg/L范围内线性关系良好,其定量下限(S/N>10)为0.5 ng/g,检出限(S/N>3)为0.25 ng/g;克伦特罗和氯霉素在0.2～6.4μg/L范围内线性关系良好,其定量下限(S/N>10)为0.1 ng/g,检出限(S/N>3)为0.05 ng/g,相关系数均大于0.99。猪肉基质在3个加标水平下,回收率为79.2%～113.6%,相对标准偏差(RSDs)为3.2%～12.0%。该方法的灵敏度、准确度和精密度均符合兽药残留测定的技术要求,适用于猪肉中β-受体激动剂和氯霉素残留的检测。     

气相色谱-串联质谱法同时测定染整助剂中乙二醇醚及其醋酸酯残留量

以乙酸乙酯为萃取溶剂对染整助剂中残留的乙二醇醚及其醋酸酯进行超声萃取后,经Waters Sep-Pak Vac Silica(1 g/6 mL)固相萃取柱净化,选用DB-Wax色谱柱(60 m×0.25 mm×0.25μm)分离,采用气相色谱-串联质谱(GC-MS/MS)方法进行多反应监测(MRM)分析,外标法定量,建立了同时测定染整助剂中15种乙二醇醚和4种乙二醇醚醋酸酯的分析方法。结果显示,19种待测物峰面积(A)与其质量浓度(ρ)在一定范围内呈线性相关,相关系数均不低于0.999 2。分别以3倍信噪比(S/N=3)和S/N=10计算方法检出限(LOD)和定量下限(LOQ),得MOPA和DEGME的LOD均为30μg/kg,DEGDEE的LOD为20μg/kg,EGEE和EGME的LOD均为10μg/kg,其余14种目标分析物的LOD为1～5μg/kg;MOPA和DEGME的LOQ均为100μg/kg,EGEE、EGME和DEGDEE的LOQ分别为20、30、50μg/kg,其余14种目标分析物的LOQ为1～15μg/kg。在低、中、高3个加标浓度水平下的平均加标回收率为82.4%～94.6%,相对标准偏差为2.7%～9.2%。该方法操作简单、灵敏度高、定量下限低,完全满足染整助剂中乙二醇醚及其醋酸酯残留量检测工作的需要。     

超声萃取/气相色谱-质谱联用法同时测定皮革及其制品中21种有害有机溶剂的残留量

建立了气相色谱-质谱/选择离子监测方法,对皮革及其制品中21种有害有机溶剂的残留量进行了同时测定。该方法以乙酸乙酯为萃取溶剂,45℃下超声萃取皮革及其制品中残留的有害有机溶剂,萃取液经固相萃取柱净化后进行气相色谱-质谱/选择离子监测法分析,外标法定量。结果表明,在信噪比(S/N)为10的条件下,乙二醇二丁醚(EGDBE)、三乙二醇二甲醚(TEGDME)、二乙二醇单丁醚(DEGBE)和三乙二醇单乙醚(TEGEE)的定量下限均为50μg/kg,N-甲基乙酰胺(MA)和N-甲基甲酰胺(MF)的定量下限均为150μg/kg,甲酰胺的定量下限为300μg/kg,其余14种组分的定量下限均为100μg/kg。在3个不同加标水平下,方法的平均加标回收率为82.1%~94.9%,相对标准偏差(RSD,n=9)为1.6%~4.8%。该方法简单快捷,灵敏度高,可用于皮革及其制品中有害有机溶剂残留量的测定。     

QuEChERS/GC-MS/MS测定人参中41种农药残留

建立了QuEChERS结合气相色谱-串联质谱(GC-MS/MS)测定人参中41种农药残留的分析方法,采用选择反应监测(SRM)模式,外标法定量,并考察了Original、Acetate和Citrate 3种QuEChERS前处理方法对人参基质中目标农药的提取效率和净化效果。结果表明,采用Original QuEChERS前处理方法时,41种农药在一定浓度范围内的线性良好,相关系数(r)大于0.995,方法的检出限(LOD,S/N=3)为2.0～6.0μg/kg,定量下限(LOQ,S/N=10)为5.0～20.0μg/kg。在10、20、100、200μg/kg 4个加标水平下的回收率为86.7%～115%,相对标准偏差(RSD)均小于15%。该方法样品前处理简单、高效、准确、灵敏,适用于人参中多农药残留的筛选与测定。     

土壤中13种磺酰脲类除草剂多残留的超高效液相色谱-串联质谱法测定

建立了超高效液相色谱-串联质谱法同时检测土壤中13种磺酰脲类除草剂多残留量的方法。样品经磷酸缓冲液(pH7.8)-甲醇(体积比1∶1)振荡提取,Oasis HLB固相萃取小柱净化后,采用多反应监测模式测定,外标法定量。13种磺酰脲类除草剂在5～200μg/L范围内线性关系良好,相关系数为0.999 1～0.9999。13种除草剂在5、20μg/kg水平下的平均加标回收率为89%～103%,相对标准偏差为1.1%～11.2%。方法的检出限(S/N=3)为0.020～0.092μg/kg,定量下限(S/N=10)为0.07～0.31μg/kg。     

超高效液相色谱-串联质谱法测定葡萄干中27种农药残留

建立了同时快速检测葡萄干中氨基甲酸酯类杀虫剂、三唑类杀菌剂及其他杀菌剂、杀虫剂等27种农药的超高效液相色谱-串联质谱法(UPLC-MS/MS)。样品采用0.1%冰乙酸-乙腈溶液直接提取,QuEChERS方法净化,电喷雾正离子(ESI+)模式电离,多反应监测(MRM)模式检测,基质匹配曲线外标法定量。结果表明:27种农药在5～100μg/kg的浓度范围内线性良好(r≥0.993),在10、20、50μg/kg加标水平下,27种农药的平均回收率分别为60%～97%、62%～97%和64%～99%;相对标准偏差(RSD)分别为3.0%～13.0%、1.6%～9.6%和3.3%～9.6%,方法的定量下限(信噪比S/N≥10)为10μg/kg。该方法简便、快速、灵敏、准确,适于葡萄干中多种农残的确证和定量测定。     

液相色谱-串联质谱法测定食品接触材料中28种初级芳香胺的迁移量

建立了液相色谱-串联质谱法(LC-MS/MS)同时测定食品接触材料中28种初级芳香胺(PAAs)迁移量的方法。采用C3色谱柱,以甲醇-水为流动相,梯度洗脱分离,在电喷雾正离子模式下以多反应监测(MRM)方式检测,外标法定量。28种PAAs检出限(LOD,S/N=3)和定量限(LOQ,S/N=10)分别为0.02～0.3μg/kg和0.1～1.0μg/kg;在1.0～1000μg/L浓度范围内线性良好,相关系数大于0.9915;加标浓度在1.0～100μg/kg的回收率为77.8%～105.3%;相对标准偏差(RSD)为4.5%～11.8%。本方法操作简便、快速、准确、灵敏度高,能满足相关测定要求。     

高效液相色谱串联质谱法测定中药注射剂对P815细胞脱颗粒后上清液中组胺含量

建立了液相色谱-串联质谱(LC-MS/MS)检测P815细胞脱颗粒后上清液中组胺含量的方法。采用C18柱(4.6 mm×100 mm,3.5μm)进行分离,以体积比为60∶40的乙腈-0.5 mmol/L乙酸铵溶液(含0.3%甲酸)为流动相,流速0.4 mL/min;在电喷雾正离子化模式下,采用多离子反应检测方式(MRM)进行检测;检测离子对为m/z 112>95、112>68。在优化条件下,样品可在6 min内完成分析,细胞液中组胺在4.0～128.0μg/L范围内线性关系良好(r2=0.997 9)。定量下限(S/N>10)为1.2μg/L,检出限(S/N=3)为0.3μg/L。在加标水平为16、64、128μg/L时,细胞上清液中组胺的平均回收率为90%～94%,相对标准偏差(n=6)为4.1%～5.9%。该方法简便、灵敏、重复性好,可用于中药注射剂对P815细胞脱颗粒后上清液中组胺含量的测定。     

液相色谱-串联质谱法测定水产品中亮绿、亚甲基蓝及其代谢物残留量

建立了水产品中亮绿、亚甲基蓝及其代谢物残留量同时测定的液相色谱-串联质谱(LC-MS/MS)方法。样品经乙酸铵缓冲溶液和乙腈提取,二氯甲烷液液萃取,PRS固相萃取柱净化,氮吹浓缩,定容后测定。以2 mmol/L乙酸铵(含0. 1%甲酸)、乙腈和甲醇为流动相,CAPCELL PAK C_(18)色谱柱进行分离,在选择反应监测(SRM)模式下测定,外标法定量。在最佳实验条件下,5种化合物在1. 0～100. 0μg/L范围内线性关系良好(r~2 0. 999),检出限(LOD,S/N≥3)均为1. 0μg/kg,定量下限(LOQ,S/N≥10)均为2. 0μg/kg;在水产品中加标水平为1. 0、5. 0、10. 0μg/kg时,回收率为70. 3%～92. 1%,相对标准偏差(RSD,n=6)为2. 3%～13%。该方法灵敏度高,能有效检测水产品中亮绿、亚甲基蓝及其代谢物的残留量。     

固相萃取/液相色谱-串联质谱对瓜果中7种植物生长调节剂残留的测定

建立了固相萃取/液相色谱-串联质谱技术(LC-MS/MS)同时检测橙中2,4-二氯苯氧乙酸、赤霉素、吲哚-3-丁酸、α-萘乙酸、对氟苯氧乙酸、对氯苯氧乙酸和吲哚-3-乙酸7种植物生长调节剂(PGRs)残留量的分析方法。样品经含2%甲酸的乙腈溶液提取,Poly-Sery MAX混合型阴离子交换固相萃取柱净化后,以含4%甲酸的甲醇溶液洗脱,氮吹至近干以1 mL乙腈-水(1∶9)溶液定容,采用Phenomenex Gemini-NX 5uC18110A柱(2.0 mm i.d.×150 mm,5.0μm)进行分离,经液相色谱-串联质谱法在多反应监测(MRM)模式下检测,基质匹配溶液外标法定量。结果表明,7种植物生长调节剂在各自范围内线性关系良好,相关系数均大于0.99。7种植物生长调节剂的检出限(S/N>3)为0.3～3.5μg/kg,定量下限(S/N>10)为5.4～57.7μg/kg。空白基质橙在低、中、高3个加标水平下的回收率为79.6%～110.3%,相对标准偏差(RSDs)为3.1%～10.0%。该方法操作简便、灵敏度高,可满足对瓜果中多种植物生长调节剂残留的分析要求。     

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.