液相色谱-串联质谱法测定食用植物油中的棉酚

建立了食用植物油中棉酚的液相色谱-串联质谱（LC-MS/MS）分析方法。待测物经无水乙醇涡旋振荡提取,C18色谱柱分离,以乙腈和0.1%（v/v）甲酸水溶液为流动相进行梯度洗脱,LC-MS/MS测定,外标法定量。方法的测定低限（S/N>10）为1 mg/kg;在添加浓度为1、2和200 mg/kg水平下,棉酚的加标回收率为87.4%~100%,相对标准偏差为3.9%~12.2%。结果表明,本方法灵敏度高,测定结果准确,回收率稳定,可用于食用植物油中棉酚残留的确证检测。     

超高效液相色谱-串联质谱测定饲料中镇静剂类和β-受体激素类药物残留

采用超高效液相色谱-串联质谱技术,建立了饲料中8种镇静剂类和15种β-受体激素类药物残留的分析检测方法。样品采用乙腈-1%(体积分数)三氯乙酸水溶液(7∶3,v/v)提取,目标物通过阳离子固相萃取柱净化,经Agilent Zorbax Eclipse Plus C_(18)色谱柱(100 mm×3.0 mm,1.8μm)分离,液相色谱-串联质谱进行检测,标准曲线内标法定量。结果表明:23种目标物在2.0~200.0μg/L内线性关系良好(r20.99)。在饲料样品基质中,目标化合物在5.0、10、50μg/kg 3个加标水平下的平均回收率为75.1%~102.4%,相对标准偏差(RSD)为4.3%~14.3%(n=6)。该方法净化效率高,适用范围广,可用于饲料中镇静剂类和β-受体激素类药物残留筛查和检测。     

液相色谱-串联质谱法测定育肥猪配合饲料中的阿奇霉素

通过对提取溶剂、净化方法及色谱-质谱条件的优化,建立了配合饲料中阿奇霉素(AZM)的液相色谱-串联质谱测定方法。样品经乙腈超声波提取,MCX固相萃取柱净化,BDS Hypersil C_(18)(2.4μm,100 mm×2.1 mm)色谱柱分离,以甲醇-0.05 mol/L乙酸铵水溶液为流动相梯度洗脱,正离子模式电离,多反应监测模式检测,同位素内标法定量。在优化条件下,AZM在1~250μg/L范围内线性关系良好,相关系数(r~2)为0.999 1,检出限(S/N≥3)为2.8μg/kg,定量下限(S/N≥10)为8.4μg/kg;在0.5,1,5,10 mg/kg加标水平下,回收率为87.0%~106.6%,批内相对标准偏差为0.58%~5.4%,批间相对标准偏差为3.1%~5.4%。该方法准确、灵敏,选择性强,基质干扰小,可用于配合饲料中AZM的测定。     

凝胶渗透色谱-高效液相色谱-串联质谱法同时测定烟草中3种抑芽剂残留

建立了用凝胶渗透色谱净化-液相色谱-串联质谱分析烟草中3种抑芽剂残留的方法。卷烟中的待测抑芽剂组分用V(乙酸乙酯)∶V(环己烷)=1∶1超声提取后通过凝胶渗透色谱净化;凝胶色谱柱为Biobeads S-X3玻璃柱(50 g,400 mm×25 mm),流动相为V(乙酸乙酯)∶V(环己烷)=1∶1溶液,流速5 mL/min;收集第10~25 min流出的液体用液相色谱色谱-三重四极杆串联质谱仪测定。在0.5~100 ng/mL的质量浓度范围内,各种抑芽剂标准溶液的线性相关系数均大于0.99。在样品中添加3种抑芽剂(添加水平为5,20,100μg/kg)的混合标准溶液,平均回收率在86.2%~108.4%之间,3种抑芽剂的RSD在1.1%~7.5%之间;方法的检测限在0.01~0.06μg/kg之间。     

高效液相色谱-串联质谱法快速测定水产品中19种喹诺酮类药物残留

应用PRiME HLB净化技术,采用超高效液相色谱-串联四极杆质谱(UPLC-MS/MS),建立了水产品中19种喹诺酮类药物残留的检测方法。对样品的净化、浓缩、液相色谱分离及串联质谱等相关检测参数进行了优化。样品经80%乙腈水溶液提取,PRiME HLB固相萃取柱净化,在ACQUITY BEH C_(18)色谱柱(1.7μm,2.1 mm×100 mm)上以甲醇和5 mmol/L乙酸铵水溶液(含0.1%甲酸)为流动相梯度洗脱,液相色谱-串联质谱MRM方式进行定量分析。结果表明:各组分在各自浓度范围内线性关系良好,平均回收率为72.1%~119.9%,相对标准偏差为2.4%~15.6%,检出限均为0.5μg/kg,定量下限均为1.5μg/kg。该方法用于水产品中喹诺酮类药物残留的检测,具有准确、快速、简便、灵敏度高等优点,为水产品中喹诺酮类药物残留的测定提供了新途径。     

QuEChERS结合高效液相色谱-串联质谱法测定饲料中的18种β-兴奋剂

建立了饲料中克仑特罗、莱克多巴胺、喷布特罗、妥布特罗等18种β-兴奋剂的QuEChERS结合高效液相色谱-串联质谱的检测方法。饲料样品加水分散后经4%(v/v)氨水乙腈提取,加入25 mg十八烷基硅烷(C18)和50mg N-丙基乙二胺(PSA)吸附剂分散固相萃取净化后,以高效液相色谱-串联质谱进行定性和定量分析。采用Agilent Zorbax Eclipse XDB-C18(50 mm×4.6 mm,1.8μm)分析柱,以甲醇-0.1%(v/v)甲酸水溶液为流动相进行梯度洗脱,串联质谱在多反应监测(MRM)正离子模式下进行检测,基质外标法定量。结果表明,18种待测物在质量浓度为5~200μg/L范围内线性关系良好,相关系数为0.9912~0.9995;在0.05、0.1、0.5 mg/kg 3个浓度加标水平下,饲料中18种β-兴奋剂的平均回收率为78.4%~107.1%,相对标准偏差(RSD)为3.5%~12.3%,定量限(以信噪比≥10计)均为0.05 mg/kg。该方法准确、灵敏,前处理简单,可作为饲料中克仑特罗等18种β-兴奋剂筛选和确认的检测方法。     

凝胶渗透色谱-固相萃取净化/气相色谱-串联质谱法测定动物性食品中167种农药残留

建立了肉类、水产类等动物性食品中167种农药残留的气相色谱-串联质谱检测方法。样品匀浆后,采用乙腈提取,以凝胶渗透色谱和Carb-NH2萃取柱联合净化,气相色谱-串联质谱检测,外标法定量。167种农药的响应在1~200μg/L质量浓度范围内线性良好,相关系数在0.994以上,各农药的检出限为0.3~3μg/kg,定量下限为1~10μg/kg。以猪肉样品作为代表性基质,进行0.01,0.04 mg/kg 2个水平的加标回收实验,回收率为66.4%~111.5%,相对标准偏差为1.3%~17.8%。本方法准确可靠,灵敏度高,样品净化效果好,能够满足动物性食品中农药多残留的痕量分析要求。     

基于QuEChERS提取的HPLC-MS/MS法测定禽肉中的利巴韦林与金刚烷胺

建立了液相色谱-串联质谱(HPLC-MS/MS)同时测定禽肉中利巴韦林和金刚烷胺的检测方法。禽肉样品用1%(体积分数)三氯乙酸水溶液-甲醇(1∶1,体积比)提取,经PCX固相萃取柱和QuEChERS方法净化后,以含5 mmol/L乙酸铵水溶液与甲醇为流动相梯度洗脱,BEH HILIC(2.1 mm×100 mm,1.7μm)色谱柱分离,电喷雾正离子模式电离,多级反应监测(MRM)模式进行检测,内标法定量。结果表明,利巴韦林和金刚烷胺在0.50~200μg/L范围内呈良好线性,相关系数均大于0.997。两种目标分析物的方法检出限(S/N≥3)分别为0.30μg/kg和0.15μg/kg,定量下限(S/N≥10)分别为1.00μg/kg和0.50μg/kg,样品在其1倍、2倍、10倍定量下限3个加标水平下的日内回收率为92.5%~104.7%,相对标准偏差(RSD)为3.4%~7.8%;日间回收率为93.3%~106.0%,RSD为6.0%~10.7%。该方法灵敏、简便、准确,可用于禽肉中利巴韦林和金刚烷胺残留的同时检测。     

河豚鱼、鳗鱼和烤鳗中角黄素残留的超高效液相色谱法测定和超高效液相色谱-串联质谱法确证

建立了河豚鱼、鳗鱼和烤鳗中角黄素残留的超高效液相色谱测定方法和超高效液相色谱-串联质谱确证方法。样品用抗氧化剂焦性没食子酸保护,乙腈均质提取,正己烷液-液分配净化,超高效液相色谱-紫外检测器测定,外标法定量,超高效液相色谱-串联质谱法确证。测定方法采用BEHC18色谱柱(50 mm×2.1 mm,i.d.1.7μm),流动相为V(0.1%的甲酸)∶V(乙腈)=3∶97,检测波长470 nm。实验结果表明,角黄素在0.05~2.0 mg/L范围内线性关系良好(r=0.9999),在空白样品中,添加低、中、高3个浓度水平(0.05,0.1,1.0 mg/kg),角黄素的回收率均在82.52%~96.96%之间,相对标准偏差为6.9%~15%。方法的检出限(LOD)为0.02 mg/kg,定量限(LOQ)为0.05 mg/kg。串联质谱确证方法采用电喷雾(ESI)离子源,在正离子模式下以多反应监测(MRM)扫描方式检测,定性离子对565.5/203.2和565.5/133.1,定量离子对565.5/203.2。     

UPLC-MS/MS同时测定蔬菜中阿维菌素等5种常用农药残留量

建立了同时测定蔬菜样品中阿维菌素、甲氨基阿维菌素苯甲酸盐(甲维盐)、吡虫啉、茚虫威及代森锌残留量的超高压液相色谱-串联质谱法(UPLC-MS/MS)。样品经0.1%氢氧化钠溶液(含10 mmol/L L-半胱氨酸和10 mmol/L EDTA-Na2)预处理后,以乙腈作为提取溶剂,经0.2 g C18+0.05 g石墨化碳(GCB)基质分散固相萃取净化。各待测物经Thermo Hypersil BDS C18(100 mm×4.6 mm,2.6μm)色谱柱进行分离,以10 mmol/L氨水-乙腈作流动相梯度洗脱,串联质谱法对5种农药残留量进行测定。结果表明,代森锌在50~2 000μg/L范围内,另4种农药在5~200μg/L范围内线性关系良好,相关系数(r2)为0.995 1~0.999 9。在0.5~500μg/kg加标浓度下,豆角、辣椒、青菜、黄瓜、芦笋、蕃茄中5种农药的加标回收率为70.8%~103.6%,相对标准偏差(RSD)为4.5%~13.9%;代森锌的检出限为8.2~30μg/kg,定量下限为27~100μg/kg,其余4种农药的检出限为0.02~0.7μg/kg,定量下限为0.07~2.3μg/kg。方法快速准确、经济实用,可满足日常检测的需要。     

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.