超高效液相色谱-串联质谱法测定化妆品中61种性激素

建立了一种超高效液相色谱-串联质谱法测定化妆品中61种性激素的方法。水基类、乳液类、膏霜类和凝胶类化妆品经乙腈分散,50%(V/V)乙腈水溶液超声提取;油基类样品经正己烷分散,70%(V/V)乙腈水溶液涡旋提取。采用CORTECS C18(2.1 mm×150 mm, 2.7μm)色谱柱进行分离,选择乙腈、水为流动相进行梯度洗脱,多反应监测(MRM)模式检测,基质外标法定量。结果表明,61种性激素的检出限和定量限分别为0.03～0.31μg/g和0.09～0.92μg/g,在15～150μg/L范围内线性关系良好(相关系数R²>0.99)。选择了5种化妆品基质,在低、中、高3个加标水平下,61种性激素的加标回收率为80.0%～117.7%,相对标准偏差(RSD)为1.5%～14%。该方法可以为化妆品的快速风险筛查和国家标准的制修订提供技术支撑。     

高效液相色谱-二极管阵列/荧光检测器串联法同时测定化妆品中8种性激素

建立了高效液相色谱(HPLC)-二极管阵列(DAD)/荧光检测器(FLD)串联测定化妆品中雌三醇、雌二醇、睾酮、炔雌醇、己烯雌酚、乙酸甲地孕酮、孕酮和丙酸睾酮8种性激素的分析方法。所有形态的化妆品样品均以甲醇超声提取进行前处理,乳膏状样品再经HLB固相萃取柱富集净化,以乙腈/水为流动相梯度洗脱,经ZORBAX Eclipse XDB-C18柱分离,DAD-FLD串联法检测。8种性激素获得了满意的分离并排除了样品基质的干扰。方法检出限为0.1~0.5μg/g,平均加标回收率为90.3%~102.9%(n=6),相对标准偏差为0.4%~4.8%(n=6)。方法可用于化妆品中雌三醇等8种痕量性激素的同时测定。     

超高效液相色谱-三重四极杆质谱法测定化妆品中秋水仙碱、秋水仙胺和秋水仙碱苷EI北大核心CSCD

建立了一种同时测定化妆品中秋水仙碱、秋水仙胺和秋水仙碱苷的超高效液相色谱-三重四极杆质谱分析方法。试样经正己烷饱和的甲醇-乙腈(1∶1,V/V)混合溶剂超声提取,蜡基类样品经正己烷溶解分散后提取,膏霜类样品在提取液中加入乙酸铵以改善样品乳化情况,提取液离心过滤后,以5 mmol/L乙酸铵(含0.1%甲酸)-甲醇作为流动相梯度洗脱,经ACQUITY UPLC BEH C_(18)色谱柱分离后,采用超高效液相色谱-三重四极杆质谱在电喷雾正离子电离模式和多反应监测(MRM)模式检测。3种化合物在0.5~10μg/L范围内线性关系良好,相关系数大于0.995,检出限为3.0μg/kg,定量限为10.0μg/kg,在10.0,20.0,100μg/kg 3个加标水平下的平均回收率为81.5%~109.2%,相对标准偏差为0.5%~8.7%。该方法适用于化妆品中秋水仙碱、秋水仙胺和秋水仙碱苷的测定。     

超高效液相色谱-串联质谱法同时测定化妆品中35种性激素

采用超高效液相色谱-串联质谱(UPLC-MS/MS)建立了同时测定化妆品中35种性激素的方法。样品经50%乙腈水溶液超声提取,采用CORTECS C_(18)(2.1 mm×150 mm,2.7μm)色谱柱分离,以乙腈-水为流动相进行梯度洗脱,多反应监测(MRM)模式测定。结果表明,35种性激素在各自的质量浓度范围内线性关系良好(相关系数r0.99),检出限(LOD)和定量下限(LOQ)分别为0.028～0.117μg/g和0.093～0.352μg/g。在0.25、0.50、1.00μg/g 3个加标水平下,水状、乳状和霜状3种基质样品的回收率为84.0%～117%,相对标准偏差(RSD,n=6)为1.5%～14%。该方法前处理简单、灵敏度高、准确性好,适用于化妆品中性激素的测定。     

超高效液相色谱-串联质谱法测定化妆品中全氟及多氟化合物北大核心CSCD

该文基于超高效液相色谱-串联质谱法(UHPLC-MS/MS),建立了多种类型化妆品中全氟及多氟化合物(PFASs)的分析方法。水剂、膏霜、乳液、凝胶和粉剂样品经过饱和乙酸铵-氯化钠溶液(含1%甲酸)分散后采用1%甲酸-乙腈溶液提取,油状和蜡基类化妆品经过正己烷分散后采用饱和乙酸铵-乙腈溶液(含0.001%氨水)提取,提取液以Agilent RRHD Eclipse Plus Zorbax C_(18)色谱柱(3.0 mm×100 mm,1.8μm)进行分离,在电喷雾离子源(ESI)下以多反应监测(MRM)模式检测,基质匹配外标法定量。通过考察不同前处理方式对30种PFASs回收率的影响,确定最优前处理方法。在优化条件下,30种PFASs在1~250μg/L范围内呈良好线性关系,相关系数(r^(2))为0.9903~0.9998;方法检出限为0.025~0.125μg/g,定量下限为0.050~0.250μg/g,30种PFASs的平均回收率为70.8%~112%,相对标准偏差(RSD,n=6)为0.50%~12%,24 h内各基质溶液中30种PFASs的峰面积相对标准偏差(RSD)均小于10%。采用该方法对采集的88个化妆品样品进行检测,发现1个阳性样品,检出全氟辛酸(PFOA)和全氟辛基磺酸(PFOS)含量分别为4.7μg/g和1.4μg/g。该方法简便、快速、准确、灵敏,可为化妆品的质量控制和日常监管提供技术支撑。     

气相色谱-质谱法测定化妆品中苯酚和氢醌

建立了气相色谱-质谱联用测定化妆品中苯酚和氢醌的检测方法.用甲醇作为提取试样,经HP-INNOWAX毛细管色谱柱分离,选择特征离子监测扫描模式(SIM)测定.结果表明:苯酚的方法线性范围为0.01~50μg/m L(r=0.999 96),检出限为0.05μg/g,加标回收率为91.3%~99.6%,相对标准偏差为1.5%~6.0%.氢醌的方法线性范围为0.02~50μg/m L(r=0.999 87),检出限为0.10μg/g,加标回收率为91.5%~99.7%,相对标准偏差为3.2%~5.5%.方法简单、快速、灵敏,可有效消除化妆品基质的干扰,适用于化妆品中苯酚和氢醌的定性、定量测定.     

超高效液相色谱-串联质谱法快速测定化妆品中水杨酸

提出了超高效液相色谱-串联质谱法测定化妆品中水杨酸含量的方法。化妆品试样用甲醇溶解,振荡提取20 min,离心分离取上清液过ACQUITYTMBET C18色谱柱(2.1 mm×100 mm,1.7μm)并用乙腈和甲酸-水(0.3+99.7)溶液(体积比6比4)的混合溶液作为流动相进行分离,串联质谱法进行测定。采用正离子模式多反应监测,同位素内标法定量。水杨酸的线性范围为1.0~5.0×103μg.L-1,方法的检出限(3S/N)为0.15μg.L-1,测定下限(10S/N)为0.50μg.L-1。方法用于分析8种化妆品试样,回收率在97.3%~107.0%之间,相对标准偏差(n=5)在2.0%~3.8%之间。     

稳定同位素稀释气相色谱-质谱联用测定化妆品中5种磷酸三酯类化合物

根据不同化妆品的基质特性探讨优化不同的提取净化方法,建立了稳定同位素稀释气相色谱-质谱联用测定化妆品中5种磷酸三酯类化合物(OPEs)的方法。膏霜乳液类和蜡基类化妆品经溶剂提取后,采用ENVI-Carb固相萃取柱净化;粉剂类和水剂类化妆品经溶剂提取、浓缩后直接检测。样液经DB-5MS(30 m×0.25 mm×0.25μm)色谱柱分离,GC-MS的选择离子监测(SIM)模式检测,以保留时间和特征离子丰度比定性,稳定同位素稀释内标法定量。在优化的实验条件下,5种磷酸三酯类化合物在各自的线性范围内相关系数大于0.9995,方法检出限为1.0~30μg/kg,平均回收率为89.5%~105%,相对标准偏差(n=6)为2.9%~9.1%。本方法净化效果好,可有效消除基质效应,且有较好的回收率,可用于不同类型的化妆品基质中磷酸三酯类化合物的测定。     

气相色谱-串联质谱法同时测定化妆品中28种香料成分北大核心CSCD

随着化妆品种类的日益增多,化妆品中的香精香料成分受到了越来越多人的关注,建立化妆品中香精香料成分的分析测定方法是消除人们担忧最有效的措施之一。该研究建立了气相色谱-串联质谱(GC-MS/MS)同时测定化妆品中28种香料残留的方法。样品由甲醇提取,含油脂较多的经中性氧化铝固相萃取小柱净化,色素多、基质复杂的由QuEChERS净化,待测物采用GC-MS/MS测定,以保留时间和特征离子对定性,外标法定量。实验结果表明,分析物质的检出限(S/N=3)为2~20μg/kg,定量限(S/N>10)为5~50μg/kg。28种物质分别在1~100、2~200、4~200、10~1 000μg/L范围内线性关系良好,分析物质的线性相关系数(r^(2))>0.999。在空白样品中添加28种香料,添加水平为50~500μg/kg时,回收率范围为71.3%~120.4%, RSD范围为1.5%~14.6%。该方法可对28种香料成分进行准确测定,不但可以有效排除复杂基体的干扰,而且简单、灵敏、稳定,能够很好地应用于化妆品中香料的含量测定。通过该方法对16种化妆品中的香精香料成分进行测定,发现12种化妆品中均检出相关香料成分,说明化妆品中的香精香料安全应引起重视。     

超高效液相色谱-串联质谱法测定化妆品中6种生物碱

建立了一种同时测定化妆品中6种生物碱(秋水仙碱、萝芙碱、藜芦定、西伐丁、麦角胺、麦角克碱)的超高效液相色谱-串联质谱分析方法。试样用0.1%甲酸-乙腈混合溶剂超声提取,Cleanert PCX固相萃取柱净化,经Thermo Hypersil GOLD色谱柱分离后在多反应监测模式下检测。结果表明:6种生物碱在0.2~20μg/L范围内线性关系良好(r20.999 0),方法定量下限为2.0~5.3μg/kg,3个加标水平下的平均回收率为83.9%~101.1%,相对标准偏差为0.7%~6.6%。该方法快速准确、灵敏度高,适用于化妆品中生物碱的安全性评价。     

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.     

Understanding the Diels-Alder reactivity of 1,2-azaborine analogues

The Diels-Alder reactivity of 1,2-heteroborines (H₄C₄B(H)X, X?=?NH, PH, AsH; O, S, Se) has been computationally explored by means of Density Functional Theory (DFT) calculations. The influence of the HB?=?X fragment on the reactivity of the system has been quantitatively analyzed in detail by means of the so-called Activation Strain Model (ASM) of reactivity. It is found that the interaction between these species and the dienophile is significantly stronger than that computed for their all-carbon isoelectronic counterpart, benzene. In addition, the strain energy plays a key role in the observed reactivity trends. The role of the aromaticity strength of these heteroarenes on the reactivity is also assessed.