液相色谱-串联质谱法同时测定水产品中三苯甲烷类与噻嗪类染料及其代谢产物

采用液相色谱-串联质谱法对鱼肉和虾肉中三苯甲烷类与噻嗪类染料及其代谢物进行测定。样品经对甲苯磺酸-乙酸铵-乙腈溶液提取,正己烷脱脂,二氯甲烷萃取,MCAX固相萃取净化后,以Waters BEH C18色谱柱为分离柱,以0.15%甲酸溶液(含5mmol·L-1乙酸铵溶液)-乙腈混合液为流动相进行梯度洗脱,采用电喷雾正离子源及多反应监测模式进行测定。各化合物的质量浓度在20.0μg·L-1以内呈线性,方法的测定下限(10S/N)均为0.5μg·kg-1。对空白样品进行加标回收试验,回收率在62.6%~108%之间,测定值的相对标准偏差(n=6)在2.0%~14%之间。方法用于鱼肉和虾肉样品的检测,结果与国家标准方法的测定值一致。     

高效液相色谱-串联质谱法同时测定动物源性食品中35种兽药残留量

提出了高效液相色谱-串联质谱法同时测定动物源性食品中35种兽药残留量的方法。样品经含1%(体积分数)乙酸的乙腈提取,QuEChERS方法净化,所得净化液以Zobax Eclipse Plus C18色谱柱为分离柱,以不同体积比的0.1%甲酸(体积分数)溶液和乙腈混合液为流动相进行梯度洗脱,采用电喷雾正离子源和多反应监测模式检测。35种化合物的质量分数均在1~50μg·kg-1范围内与其峰面积呈线性关系,方法的检出限(3S/N)在0.02~1.07μg·kg-1之间,测定下限(10S/N)在0.08~3.58μg·kg-1之间。以空白样品为基体进行加标回收试验,所得回收率在45.6%~121%之间,相对标准偏差(n=6)在2.4%~24%之间。     

气相色谱-质谱法同时测定土壤中30种农药残留

采用气相色谱-质谱法同时测定土壤中30种农药残留。样品经过丙酮-正己烷(1+1)混合溶液均质提取,再用正己烷进行萃取,弗罗里硅土柱净化后,采用HP-5MS色谱柱分离,选用电子轰击离子源和选择离子监测模式进行质谱分析,外标法定量。30种农药的线性范围为0.1~1.0mg·L-1,检出限(3S/N)为3.8~9.6μg·kg-1。加标回收率在75.8%~103%之间,测定值的相对标准偏差(n=6)在5.6%~9.7%之间。     

高效液相色谱-串联质谱法测定农产品中矮壮素残留量

提出了农产品中矮壮素的高效液相色谱-串联质谱(HPLC-MS/MS)分析方法。样品经甲醇-水(1+1)溶液提取,正己烷液液萃取后,采用阳离子交换固相萃取柱净化。所得净化液以阳离子交换树脂与C18混合填料色谱柱为固定相,以含0.1%(体积分数)乙酸的乙腈-10mmol·L-1乙酸铵(1+1)溶液为流动相进行等度洗脱,采用电喷雾正离子源,多反应监测模式检测,同位素内标法定量。矮壮素的线性范围为1.0~100μg·L-1,检出限(3S/N)为5μg·kg-1,测定下限(10S/N)为10μg·kg-1。矮壮素在10,100,500μg·kg-1等3个加标水平的回收率为90.5%~98.5%之间,测定值的相对标准偏差(n=6)在0.99%~2.2%之间。     

超高效液相色谱-串联质谱法测定畜产品中6种青霉素类药物残留

采用超高效液相色谱-串联质谱法快速测定牛肉和牛奶中青霉素类药物残留。样品以磷酸盐缓冲溶液提取、乙酸锌沉淀蛋白、正己烷脱脂,然后经HLB固相萃取柱净化后,采用超高效液相色谱-串联质谱分离检测,外标法定量。6种青霉素的线性范围均在25.0μg·L-1以内,检出限(3S/N)为2μg·kg-1,测定下限(10S/N)为5μg·kg-1。加标回收率在77.0%~99.8%之间,测定值的相对标准偏差(n=6)在3.7%~13%之间。     

高效液相色谱法测定鱼肉中残留磺胺类药物

建立了鱼肉中5种磺胺类药物的高效液相色谱测定方法。样品经二氯甲烷提取,正己烷脱脂后经固相萃取柱净化等预处理。用Cloversil C18色谱柱,流动相为乙酸+甲醇+水(1+10+89)进行梯度洗脱,在紫外检测波长265 nm处,检出限可达0.1μg.kg-1,线性范围为0~500μg.L-1,相关系数大于0.999 3,样品加标回收率在78.6%~87.6%之间,测定结果的RSD在3.42%~9.03%之间。     

凝胶渗透色谱-超高效液相色谱-串联质谱法测定水产品中多种同化激素残留

结合凝胶渗透色谱净化技术,建立了超高效液相色谱-串联质谱法测定水产品中6种同化激素的残留。样品经叔丁基甲醚提取,以乙酸乙酯-环己烷(1+1)溶液为流动相进行凝胶渗透色谱净化,用C18固体吸附剂净化,以C18色谱柱分离,采用电喷雾正离子源、多反应监测模式检测,外标法定量。6种激素的线性范围均为0.5~50μg·L-1,测定下限(10S/N)在0.20~1.50μg·kg-1之间。对空白样品进行加标回收试验,回收率在81.7%~90.8%之间,日间精密度(n=5)在5.8%~7.9%之间。     

凝胶色谱净化-气相色谱-质谱法同时测定烧烤肉制品中19种多环芳烃

提出了凝胶色谱净化-气相色谱-质谱法同时测定烧烤肉中19种多环芳烃含量的方法。烧烤肉样品经正己烷-二氯甲烷(1+1)溶液超声提取30min后,上清液经凝胶色谱净化,所得净化液用HP-5MS色谱柱分离,全扫描模式和选择离子监测模式测定。19种多环芳烃的峰面积与质量浓度在5~200μg·L-1范围内呈线性关系,检出限(3S/N)在0.1~0.5μg·kg-1之间。在20,40,80μg·kg-1 3个浓度水平进行加标回收试验,19种多环芳烃的回收率在58.0%~122%之间,相对标准偏差(n=6)小于21.5%。     

气相色谱-串联质谱法测定鱼肉中毒死蜱及其代谢产物3,5,6,-三氯-2-羟基吡啶的残留量

采用气相色谱-串联质谱法(GC-MS/MS)测定鱼肉中毒死蜱及其代谢产物3,5,6,-三氯-2-羟基吡啶(TCP)残留量。样品经1mol·L-1盐酸-乙腈(1+99)混合液提取,提取液于-20℃冷冻去除脂肪,浓缩近干,残渣用乙酸乙酯溶解后与N-甲基-N-叔丁基二甲基硅基三氟乙酰胺进行衍生反应,产物经净化后采用GC-MS/MS测定。毒死蜱和TCP的线性范围分别为2.0~2 000,1.0~1 000μg·L。鱼肉中毒死蜱和TCP的检出限(3S/N)分别为0.5,0.3μg·kg-1,测定下限(10S/N)分别为1.7,1.0μg·kg-1。加标回收率分别为84.6%~95.6%,73.8%~82.7%,测定值的相对标准偏差(n=6)分别小于10%,13%。     

柱前衍生-高效液相色谱法测定茶叶中的黄曲霉毒素B1

应用柱前衍生-高效液相色谱法测定茶叶中黄曲霉毒素B1的含量。样品采用乙腈(85+15)溶液提取,滤液用MycoSepTM226柱净化,加入正己烷和三氟乙酸衍生,经C18色谱柱分离,荧光检测器检测。黄曲霉毒素B1的质量浓度在0.20~10.0μg·L-1范围内与其峰面积呈线性关系,检出限(3S/N)为0.1μg·kg-1。在0.5,1.0,5.0μg·L-1等3个浓度水平进行加标回收试验,回收率在91.9%~102%之间,测定值的相对标准偏差(n=6)在1.5%~6.9%之间。     

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.