液相色谱-电喷雾质谱法同时测定水体中的壬基酚聚氧乙烯醚及其代谢产物

利用液相色谱-电喷雾质谱法同时分析水体中的壬基酚聚氧乙烯醚(NPEOs)及其代谢产物壬基酚聚氧乙烯醚乙酸(NPECs)和壬基酚(NP),用Waters Symmetry ShieldTMRP 18色谱柱,甲醇和乙酸铵溶液作为梯度洗脱的流动相,结果表明3类物质的分离效果良好,并可通过选择离子记录(SIR)模式实现NPEOs和NPECs各单体的定量。仪器的检出限为1~50 pg,选用Oasis HLB小柱进行固相萃取,回收率达75%~98%,平均标准偏差小于12%。该方法用于污水处理厂的水样测定,所取各水样中都测出了NP和NPEOs,并从氧化沟上清液中检测到NPECs。     

GC-MS法同时测定壬基酚聚氧乙烯醚短链生物降解产物

采用固相萃取-气相色谱-质谱联用法,研究了污水中壬基酚聚氧乙烯醚短链生物降解产物NP、NP1EO、NP2EO同时定量检测的方法;优化了相关色谱条件和选择定量离子。结果表明,当进样量为4μL,进样口温度为320℃时,可获得较高的色谱响应值,改善了方法的检测灵敏度;选用多个质谱特征离子进行定量分析,各种降解产物的选择离子色谱图响应值占总离子流色谱图响应值的70%左右,较准确地反映了各产物不同同分异构体的组成。该方法的相对标准偏差小于5%,NP2EO加标回收率在98.34%~101.40%之间;采用该方法对实际污水样品进行了分析,结果表明重现性较好,精密度和准确度均满足痕量分析的要求。     

凝胶过滤色谱-串联质谱法测定纺织品中的烷基酚聚氧乙烯醚

建立了纺织品中烷基酚聚氧乙烯醚的凝胶过滤色谱-串联质谱(GFC-MS/MS)分析方法。纺织品样品采用加速溶剂萃取法,以无水乙醇为提取溶剂进行提取,提取液经Sep-Pak Carbon/NH2石墨化碳黑/氨基复合型固相萃取柱净化。烷基酚聚氧乙烯醚经Shodex MSpak GF-310 2D色谱柱(150×2.0 mm)分离后,在多反应监测(MRM)模式下进行串联质谱定性及定量分析。方法对壬基酚聚氧乙烯醚(NPnEO)和辛基酚聚氧乙烯醚(OPnEO)的定量限均为0.2 mg/kg,在0.2～5 mg/kg的3个添加水平范围内,NPnEO的平均回收率为84.2%～93.5%,相对标准偏差(RSD)为3.9%～7.5%;OPnEO的平均回收率为85.5%～96.1%,RSD为3.4%～8.1%。该方法能够满足纺织品中烷基酚聚氧乙烯醚的检测要求。     

人体尿液中双酚A与壬基酚的同位素稀释的LC-MS/MS分析

采用固相萃取、高效液相色谱-质谱/质谱仪同位素稀释技术,建立了尿中双酚A(BPA)和壬基酚(NP)的检测方法.液相色谱分离用C18柱,流动相为甲醇和水,负离子电喷雾模式电离,多反应离子监测方式检测,BPA和NP的定量离子对分别为m/z 226.9/132.9、219.3/118.8, 13C和氘代同位素化合物分别做回收率控制和内标定量.BPA和NP的基质加标回收率分别为86% ～106%、90% ～114%,定量下限分别为0.97、2.3 μg/L.实际尿样的测定验证了该方法的可行性.     

双分子印迹聚合物微球选择固相萃取环境和食品样品中壬基酚和双酚A

以壬基酚(NP)、双酚A(BPA)为模板分子,a-甲基丙烯酸(MAA)为功能单体,通过乳液聚合法制备了双模板分子印迹聚合物(D-MIP),并以D-MIP为固相萃取填料,建立了双分子印迹固相萃取-高效液相色谱荧光检测环境食品中痕量NP和BPA的方法。采用红外光谱和吸附实验对其性能进行了研究。结果表明,D-MIP对NP和BPA的饱和吸附量分别为73.3和97.5 mg/g,相对选择性系数分别为2.2和1.7。在最佳条件下,本方法的线性范围为0.01~2.3 mg/L(R2>0.998),检出限(S/N=3)为0.001~0.002 mg/L。将本方法应用于江水、啤酒、鲫鱼中NP和BPA含量测定,回收率在86.4%~99.1%范围内,相对标准偏差小于6.2%。本方法选择性好、灵敏度高,对环境和食品中NP和BPA的富集、分离显示出良好的应用前景。     

高效液相色谱-串联质谱法测定环境水体中双酚A、辛基酚、壬基酚

建立了高效液相色谱-串联质谱测量水环境中的双酚A(BPA)、辛基酚(OP)、壬基酚(NP)的方法。提取方法基于液-液萃取,流动相为V(甲醇)∶V(水)=90∶10,流速200μL/min,运行时间为5min。质谱用来定量的碎片离子分别为:BPA,212.3;BPA-d16,223.4;OP,106.3;NP,106.3,定量采用内标法。仪器的检出限均为0.7pg,方法检出限均为0.07ng/L。对同一环境样品进行3个不同浓度(10、100、500 ng/L)的加标来测得回收率:BPA 79.4%~84.3%,RSD 2.7%~3.4%;NP 78.9%~112.5%,RSD 1.9%~5.0%;OP69.4%~122.7%,RSD3.4%~11.3%。基于该方法,对大连旅顺地区主要河流和排污口水体中的BPA、NP和OP进行了检测,浓度范围为35.67~753.92ng/L,与国内其他调查区域比酚类物质污染处于中等水平,而低于国外类似调查区域。     

TiO2/H2O2/超声波协同降解壬基酚聚氧乙烯醚溶液

采用经过处理的锐钛矿型TiO2作为催化剂,在H2O2存在下,以TiO2/H2O2/超声波协同降解壬基酚聚氧乙烯醚反应为模型,探讨了TiO2催化剂用量、H2O2用量、超声波功率、壬基酚聚氧乙烯醚溶液初始浓度、初始pH值对壬基酚聚氧乙烯醚降解率的影响。结果表明,在一定的超声波功率和一定的TiO2用量范围内,壬基酚聚氧乙烯醚降解率随超声波功率和TiO2用量的增大而增大,达到一定值后保持平稳;当H2O2浓度介于一定范围内,增大H2O2用量可提高壬基酚聚氧乙烯醚的降解率,但H2O2用量过多时,反而会使壬基酚聚氧乙烯醚的降解率下降;pH<5时,壬基酚聚氧乙烯醚降解效果较好,且pH值越小,降解率越高;pH>5时,降解率越来越低。TiO2/H2O2/超声波体系降解壬基酚聚氧乙烯醚产生了较强烈的协同效应,在同一时刻三者协同体系的降解率比其3种单独体系的降解率之和高出约60%;在TiO2催化剂用量0.4g/L、H2O2用量0.2g/L、超声波功率600W、降解时间120min的条件下,对初始质量浓度为80mg/L,pH=1的壬基酚聚氧乙烯醚溶液进行降解,其降解率达98%以上。     

高效液相色谱法同时测定环境水体中的双酚A、辛基酚和壬基酚

建立了高效液相色谱-荧光检测法同时测定环境水体中双酚A(BPA)、辛基酚(DP)和壬基酚(NP)的方法。比较了液液萃取(LLE)和固相萃取(SPE)两种前处理方法,并设计了供复杂样品使用的净化柱。水样经萃取后,用轻柔氮气吹干,甲醇溶解,采用Phenomenex Luna C18色谱柱,以乙腈-水为流动相进行梯度洗脱,在激发波长275nm、发射波长300nm下进行荧光检测。结果表明,BPA、NP、OP的仪器检出限(S/N=3)分别为1μg/L、2μg/L和1μg/L。SPE法操作简单快捷,虽然NP、OP的回收率低于LLE法,但仍能满足对环境样品的测定要求。净化柱净化效果较好,能够进一步去除基质干扰,满足特别复杂水样的前处理。方法基于不同样品处理的浓缩倍数不同,三种物质的检出限在0.001～0.004μg/L之间。环境水样中BPA、NP和OP的加标回收率分别为86.2%～104%、61.6%～109%和81.5%～100%,相对标准偏差(RSD)分别为2.9%～6.4%、2.4%～5.6%和2.7%～6.9%。     

超高效液相色谱-串联质谱法测定泉州市洛阳江水体中4种壬基酚聚氧乙烯醚降解产物的含量

水样过玻璃纤维滤膜后,在滤液中加入适量内标正壬基酚-d₄(4-n-NP-d₄)溶液,使其质量浓度达到10.0μg·L^-1,涡旋混匀后备用。底泥样品或生物样品的可食部分经除杂、冷冻干燥、研磨后,分取1 g底泥样品或0.2 g生物样品,加入1 000μg·L^-1 4-n-NP-d₄内标溶液100μL和甲醇(底泥样品提取溶剂) 5.0 mL或乙腈(生物样品提取溶剂) 5.0 mL,振荡30 s,超声30 min,离心5 min,收集上清液。重复提取一次,合并上清液,并使其中的4-n-NP-d₄质量浓度达到10.0μg·L^-1。将上述样品溶液引入超高效液相色谱-串联质谱仪,其中的壬基酚聚氧乙烯醚降解产物[壬基酚单乙氧基醚(NP1EO)、壬基酚二乙氧基醚(NP2EO)、对壬基酚(4-NP)和正壬基酚(4-n-NP)]在Shim-pack GIS C₁₈色谱柱上以体积比95∶5的甲醇和1 mmol·L^-1     

流动注射在线预富集-高效液相色谱法测定水中的4-壬基酚和双酚A

建立了以香烟过滤嘴作吸附剂,在线固相萃取(SPE)与高效液相色谱(HPLC)联用测定水中双酚A(bisphenol A,BPA)和4-壬基酚(4-nonylphenol,4-NP)的方法。对于高效液相(HPLC)在线固相萃取而言,采用内置香烟过滤嘴的预富集圆形柱来代替传统的高效液相仪中的注射管进样环用于在线固相萃取。通过流动注射仪将样品分析物负载加入到预富集柱中,随后采用V(甲醇):V(H2O)=93:7混合液为洗脱剂对富集的样品分析物进行洗脱。采用Eclipse XDB-C18色谱柱,V(甲醇):V(H2O)=93:7混合液为流动相,流速为1.0mL/min,紫外检测波长为227nm,保留时间定性,外标法定量。双酚A在0.005～0.8mg/L、4-壬基酚在0.04～8.0mg/L范围内,两者峰面积与浓度呈线性关系,相关系数分别为0.9985和0.9983,检出限(S/N=3)分别为2.1和10.0μg/L,富集倍数分别为816和346倍。对标准混合物(BPA:0.2mg/L;4-NP:2.0mg/L)重复测量11次的相对标准偏差为2.3%和1.5%。本方法用于当地河流水样中BPA和4-NP的测定,回收率为93.2%～105.4%。     

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.