超高效液相色谱-串联质谱法测定化妆品还原液内的4-氨基联苯

建立了超高效液相色谱-串联质谱(UPLC-MS/MS)检测化妆品还原液中4-氨基联苯的方法.化妆品试样经过连二亚硫酸钠化学还原后,离心、PCX固相萃取小柱提取富集、净化,并经氨化甲醇洗脱、氮吹至近干,定容后通过UPLC-MS/MS仪检测,分离柱为Waters Acquity BEH C18柱;流动相为0.3％乙腈-甲酸水溶液;流速0.5mL/min.5种不同基质中4-氨基联苯在5～250 ng/mL浓度范围内呈良好的线性关系,线性回归系数r2均大于0.999,检测限均为1 ng/mL.5种不同基质中4-氨基联苯的回收率为80.9％～92.6％,相对标准偏差(RSD)为0.51％～3.76％(n=3).     

超高效液相色谱-串联质谱法测定化妆品中的6种镇痛类化学成分

建立了同时测定化妆品中氨基比林、非那西丁、双氯芬酸钠、吲哚美辛、保泰松、氯苯那敏等6种镇痛类化学成分含量的超高效液相色谱-串联质谱(UHPLC-MS/MS)法.以膏霜、面膜、啫喱和喷雾类样品为代表性基质,化妆品样品采用乙腈进行超声辅助液液萃取,采用ACQUITY UPLC BEH C18柱(2.1 mm×100 mm,...     

超高效液相色谱-串联质谱法同时测定祛痘类化妆品中保泰松与氨基比林的研究

建立了快速测定祛痘类化妆品中保泰松和氨基比林的固相萃取/超高效液相色谱-串联质谱分析方法。样品以乙腈为提取溶剂超声萃取,经Oasis HLB固相萃取柱净化浓缩后,采用Eclipse XDB-C_(18)(3.5μm,4.6 mm×150 mm)色谱柱进行分离,甲醇-10 mmol·L~(-1)乙酸铵溶液为流动相梯度洗脱,流速为0.5mL·min~(-1)。采用电喷雾正离子源(ESI+),多反应监测(MRM)扫描方式检测,基质匹配标准曲线法定量。结果表明,保泰松和氨基比林在2.0~200.0μg·L~(-1)范围内线性关系良好,相关系数(r2)均大于0.99,方法检出限分别为1.5、0.8μg·kg~(-1),定量下限分别为4.9、2.7μg·kg~(-1)。低、中、高3个加标水平下的平均回收率为77.8%~93.4%,日内相对标准偏差(RSD)为2.4%~7.8%,日间RSD为3.6%~9.5%。该方法简捷、快速、检出限低,能够为化妆品中保泰松和氨基比林残留状况的监测工作和产品质量控制提供科学依据和技术支持。     

高效液相色谱-串联质谱法检测水体沉积物中阿维菌素的残留量

建立了水体沉积物中阿维菌素残留的高效液相色谱-串联质谱(HPLC-MS/MS)检测方法。沉积物样品采用超声微波萃取、固相萃取净化。待测物通过Thermo-C18色谱柱(50 mm×2.1 mm,1.9μm)分离,乙腈∶乙酸-乙酸铵缓冲液∶水混合溶液(75∶10∶15,体积比)为流动相洗脱,大气压化学电离-多反应负离子监测模式检测,内标法定量。通过加入内标物甲氨基阿维菌素苯甲基盐并采用基质加标标准曲线进行校正。研究表明,阿维菌素的线性范围为1.6～400μg/L,相关系数(r2)达到0.999 3。不同浓度加标样品的相对标准偏差(n=3)为2.2%～16.2%,方法的检出限为0.18 ng/g(干重)。野外样品检测显示,HPLC-MS/MS方法与衍生化-液相色谱/荧光检测法的分析结果相当,但前者更灵敏、简便,适用于沉积物中痕量阿维菌素残留的测定。     

高效液相色谱-串联质谱法检测发酵液中的印楝素A

建立了一种高效液相色谱-电喷雾电离串联质谱联用仪(HPLC-MS/MS)检测发酵液中印楝素A的方法。样品经有机溶剂萃取,旋转蒸发浓缩,乙腈溶解定容,以Kinete C_(18)色谱柱(2.1 mm×100 mm,2.6μm)分离。流动相0.1%甲酸乙腈溶液和0.1%甲酸水溶液,体积比为45:55,总流速为0.2 mL·min~(-1)。电喷雾正离子电离(ESI~+)方式,多反应监测(MRM)模式下进行质谱检测,基质匹配外标法定量。目标物在6～48 ng·mL~(-1)之间线性关系良好,相关系数R=0.9993,检出限(3S/N)为0.5 ng·mL~(-1),日间重复性RSD=1.279%(n=3)。三个添加水平下(6、24、48 ng·mL~(-1))平均回收率为81.5%～87.4%,RSD为3.1%～4.4%。该方法样品前处理简单,分析时间短,准确度、精确度高,可用于发酵液中印楝素A的痕量检测。     

液相色谱-串联质谱法测定化妆品中9种禁用芳香胺

应用液相色谱-串联质谱法测定化妆品中联苯胺、4,4′-二氨基二苯醚、邻氨基甲苯醚、3,3′-二甲基联苯胺、2,4,5-三甲基苯胺、4,4′-二氨基二苯硫醚、5-硝基-邻甲苯胺、3,3′-二氯联苯胺、4-氨基偶氮苯等9种禁用芳香胺的含量。样品经1%(φ)三氯乙酸溶液和乙腈提取,分取部分上清液经固相萃取小柱净化。所得净化液以C18色谱柱(50mm×4.6mm,1.8μm)为分离柱,以不同体积比的0.05%(φ)甲酸溶液和含0.05%(φ)甲酸的乙腈的混合液为流动相进行梯度洗脱,采用电喷雾正离子源多反应监测模式检测。3,3′-二氯联苯胺的线性范围为0.5~50mg·kg-1,检出限(3S/N)为0.15mg·kg-1。其余8种芳香胺的线性范围均为0.2~50mg·kg-1,检出限(3S/N)均为0.05mg·kg-1。加标回收率在78.3%~103%之间,测定值的相对标准偏差(n=6)均小于6.0%。     

超高效液相色谱-串联质谱法测定化妆品中的腈菌唑

建立了超高效液相色谱-串联质谱法测定化妆品中腈菌唑的方法。试样经乙腈提取,正己烷萃取除去脂溶性杂质,氮气吹干富集,采用UPLC-MS/MS,以C18色谱柱分离,电喷雾电离(ESI),正离子,多反应监测(MRM)模式检测,外标法定量。在1~100 ng·mL-1范围内,线性相关系数0.99;添加回收率范围82.4~91.5%,相对标准偏差(RSD)4.8%~9.5%,方法定量下限0.5μg·kg-1。该方法快速、检测灵敏度高,可适用于各类化妆品中腈菌唑的测定。     

高效液相色谱-串联质谱法测定化妆品中壬基苯酚

提出了高效液相色谱-串联质谱法测定化妆品中壬基苯酚含量的方法。化妆品试液用甲醇-二氯甲烷（8+2）混合溶液超声提取30 min[唇膏类试样用无水乙醇-二氯甲烷（8+2）混合溶液],离心分离取上清液过Oasis HLB固相萃取柱净化。从SPE净化柱所得淋出液,以WatersXBridge C₁₈色谱柱（2.1 mm×150 mm,3.5μm）为固定相分离,以不同体积比的甲醇和氨水（0.1+99.9）溶液为流动相梯度洗脱,串联质谱进行测定。采用电喷雾负离子模式多反应监测,内标法定量。壬基苯酚的线性范围为10～500μg·L^-1,测定下限（10S/N）为0.2 mg·kg。方法用于分析4种类型化妆品样品,回收率在83.1%～103.0%之间,相对标准偏差（n=6）在2.75%～9.24%之间。     

超高效液相色谱-串联质谱法同时测定蜂蜜中硝基咪唑类、磺胺类、喹诺酮类兽药残留

建立蜂蜜样品中硝基咪唑类、磺胺类、喹诺酮类共36种兽药残留的固相萃取-超高效液相色谱-串联质谱检测方法。蜂蜜样品用H3PO4溶液(体积分数0.1%)溶解后,过滤,用Oasis HLB和PSA固相萃取柱净化,外标法定量。测定时用Eclipse Plus C18色谱柱(100 mm×2.1 mm,1.8μm)分离,乙腈-甲醇-甲酸溶液梯度洗脱,质谱测定采用多反应监测(MRM)模式。36种兽药的检出限在0.4～4.0 ng/mL,回收率在63.2%～125.5%,相对标准偏差均低于22%。     

超高效液相色谱-串联质谱法同时测定浓缩果汁中的18种多酚物质

建立了浓缩果汁中18种多酚物质的超高效液相色谱(UPLC)-串联质谱(MS/MS)检测方法.样品经水稀释,HLB固相萃取净化,浓缩蒸干后用甲醇和0.1%甲酸定容.采用Acquity UPLC BEH C18 (1.7μm ×2.1 mm ×50 mm)色谱柱分离,以甲醇和0.1%甲酸为流动相,在0.3 ml,·min-...     

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.     

A carbanion induced synthesis of highly congested pyrazole and imidazole containing heterocycles

An efficient approach to the synthesis of highly congested di, penta and hexacyclic pyrazoles as well as imidazole fragment containing novel heterocyclic molecule has been developed through a carbanion induced transformation of suitably functionalized 2H-pyran-2-ones, benzo[h]chromene and thiochromeno[4,3-b]pyrans. Due to the presence of fluorescence, we report their prime application metal sensor as off/on switching in ferric ions.     

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.     

Selective synthesis of 4,5-dihydroimidazo- and imidazo[1,5-a]quinoxalines via modified Pictet–Spengler reaction

An efficient tandem approach for the selective synthesis of 4,5-dihydroimidazo[1,5-a]quinoxalines 6a–g and imidazo[1,5-a]quinoxalines 7a–h by the reaction of 2-imidazolyl anilines 4a–c with aryl aldehydes 5a–k under mild reaction conditions is described. Introduction of electron releasing alkyl groups in substrates 4a–b was found to be instrumental for the success of the reaction.