六溴环十二烷异构体在(魚回)鱼体内的浓度分布与生物累积特征

研究了(魚回)鱼体内六溴环十二烷(HBCDs)异构体的浓度分布与生物累积特征.首先采用基质固相分散(MSPD)法,同位素稀释定量,高效液相色谱-电喷雾串联质谱(HPLC-ESI-MS/MS)检测技术,建立了渔业饲料和鱼体中α-HBCD、β-HBCD和γ-HBCD的分析方法.该法对α-HBCD、β-HBCD、γ-HBCD的回收率分别为80.7%～110.5%、80.1%～109.0%、86.9～104.5%,其检出限分别为0.002、0.002、0.001 ng/g.采用所建立的方法对25个渔业饲料样品和30个鱼样品进行分析,三种异构体在渔业饲料中的检出率均为16%,在鱼产品中的检出率分别为10 %、6.67%和10%.鱼中HBCDs含量与渔业饲料中HBCDs含量的比值(生物累积因子)的结果为:α-HBCD,0.78;β-HBCD,0.45;γ-HBCD,1.08.对HBCDs在配对的渔业饲料与鱼中的相关关系进行了研究.     

高效液相色谱-质谱法测定动物源性食品中六溴环十二烷和四溴双酚A

建立了同时测定六溴环十二烷(HBCD)和四溴双酚A(TBBPA)的高效液相色谱-串联质谱(HPLC-MS/MS)分析方法。考察了不同前处理方法对检测结果的影响,实验结果表明,手动填充酸化硅胶柱可解决TBBPA回收率偏低和不能同时分析的问题。该方法 HBCD三种异构体α-HBCD、β-HBCD和γ-HBCD的检测限和定量限分别为30.6、102.0pg/g,9.5、31.7pg/g和17.4、58.0pg/g(以脂肪计);TBBPA的检测限和定量限分别为30.9、103.0pg/g(以脂肪计)。样品的回收率为89.1%~114.0%,并运用标准物质对建立的方法进行了验证。     

高效液相色谱-电喷雾质谱法测定环境大气中的六溴环十二烷

优化了环境大气样品前处理步骤中复合硅胶柱的净化条件,建立了高效液相色谱-电喷雾-质谱(HPLC-ESIMS)测定环境大气中六溴环十二烷(hexabromocyclododecanes,HBCDs)的分析方法。样品经正己烷提取后,采用复合硅胶柱净化,以50 mL正己烷和100 mL正己烷-二氯甲烷(9∶1,v/v)为淋洗液,以180 mL正己烷-二氯甲烷(4∶1,v/v)为洗脱液。采用UF-ODS柱(150 mm×2.1 mm,3.0μm),以乙腈-甲醇-水为流动相进行梯度洗脱,在电喷雾负离子源、选择离子监测(SIM)模式下检测。在优化的条件下,α-HBCD、β-HBCD和γ-HBCD能很好地分离,在1~100μg/L范围内,α-HBCD、β-HBCD和γ-HBCD与进样内标D_(18)-γ-HBCD峰面积的比值与对应的质量浓度均具有良好的线性关系,相关系数(R)≥0.998 8。α-HBCD、β-HBCD和γ-HBCD的仪器检出限(S/N=3)分别为0.4、0.5和0.4μg/L;定量限(S/N=10)分别为1.4、1.6和1.3μg/L;方法检出限(MDL)分别为0.13、0.17和0.13pg/m~3(n=5);实际样品的加标回收率为74.8%~95.8%。该法灵敏度高,选择性好,可以满足大气样品中HBCDs的监测和分析需求。     

六溴环十二烷异构体在鮰鱼体内的浓度分布与生物累积特征

研究了鮰鱼体内六溴环十二烷(HBCDs)异构体的浓度分布与生物累积特征。首先采用基质固相分散(MSPD)法,同位素稀释定量,高效液相色谱-电喷雾串联质谱(HPLC-ESI-MS/MS)检测技术,建立了渔业饲料和鱼体中α-HBCD、β-HBCD和γ-HBCD的分析方法。该法对α-HBCD、β-HBCD、γ-HBCD的回收率分别为80.7%~110.5%、80.1%~109.0%、86.9%~104.5%,其检出限分别为0.002、0.002、0.001 ng/g。采用所建立的方法对25个渔业饲料样品和30个鱼样品进行分析,三种异构体在渔业饲料中的检出率均为16%,在鱼产品中的检出率分别为10%、6.67%和10%。鱼中HBCDs含量与渔业饲料中HBCDs含量的比值(生物累积因子)的结果为:α-HBCD,0.78;β-HBCD,0.45;γ-HBCD,1.08。对HBCDs在配对的渔业饲料与鱼中的相关关系进行了研究。     

超高效液相色谱-电喷雾离子源-串联三重四极质谱分析土壤中六溴环十二烷

建立了加速溶剂萃取-超高效液相色谱-电喷雾离子源-串联三重四极质谱(ASE-UPLC-ESI-MS/MS)分析环境土壤样品中六溴环十二烷(HBCD, C12H18Br6)3个主要异构体α-、β-、γ-HBCD的方法.土壤样品用正己烷/丙酮(3: 1, V/V)萃取,采用由下往上填充6 g活性硅胶、3 g 44%酸性硅胶(w/w)、3 g 无水硫酸钠的复合硅胶柱富集纯化,内标法定量.3个平行基质土样本加标54 ng ΣHBCD,ΣHBCD回收率为(104.6±3 7)%.应用建立的方法对HBCD生产工厂周围环境土壤样品中α-、β-、γ-HBCD进行了测定,土壤样品中ΣHBCD含量为2.8～144.5 ng/g 干重.γ-HBCD是土壤样品中主要HBCD异构体(73.7±4.7)%;其次为α-HBCD(14.6±3.4)%; β-HBCD含量最低(11.7±1.7)%.     

加速溶剂萃取-固相萃取-液相色谱-电喷雾串联质谱法同时测定羊栖菜中六溴环十二烷异构体

采用同位素稀释-高效液相色谱-电喷雾串联四级杆质谱法同时测定羊栖菜中3种六溴环十二烷(HBCD)非对映异构体.羊栖菜样品磨碎、加入同位素内标13C-HBCD后以乙酸乙酯为提取溶剂,采用加速溶剂萃取法,使用Waters X Bridge(TM)C18反相柱分离;流动相为10mmoL的乙酸铵/乙腈(0.1%乙酸)/甲醇,在等度条件下分析,目标分析物在多反应监测(MRM)模式下以保留时间和离子对(母离子和两个碎片离子)信息比较进行定性分析,内标法定量.结果表明,在7min内即可完成α,β和γ-HBCD 3种同分异构体的分离,检测限(LOD)为0.3～1.0ng/g,定量限(LOQ)为1.0～4.0ng/g,添加水平为5、10和25ng/g时,3种被测物的加标回收率为92.7%～102.5%,相对标准偏差小于3.9%.本方法为评价羊栖菜样品质量提供了新的检测方法.     

超高效液相色谱-串联三重四极杆质谱法测定乳清蛋白粉中α-乳白蛋白和β-乳球蛋白

建立了超高效液相色谱-串联三重四极杆质谱(UPLC-MS/MS)法测定乳清蛋白粉中α-乳白蛋白(α-La)和β-乳球蛋白(β-Lg)的分析方法。样品经碘代乙酰胺烷基化,再经碱性胰蛋白酶酶解。在Waters ACQUITY UPLC-BEH C_(18),300?色谱柱上分离,流动相为0.1%甲酸水和0.1%甲酸乙腈,采用梯度洗脱分离,正离子多反应监测模式(MRM)检测,内标法定量。结果表明,α-乳白蛋白和β-乳球蛋白分别在40～1 000 nmol/L和80～2 000 nmol/L范围内呈良好线性关系,定量下限(S/N=10)均为0.020 g/100 g;加标回收率为84.7%～95.6%,相对标准偏差(RSD,n=6)为1.6%～5.8%。基于上述方法对5个国家的4类乳清蛋白粉(脱盐乳清粉D70和D90、浓缩乳清蛋白粉和α-乳白蛋白粉)进行了含量测定和差异对比。该方法操作简便,定量准确,可用于乳清蛋白粉等蛋白类原料中α-乳白蛋白和β-乳球蛋白的测定。     

气相色谱法测定鳗鱼中残留的硫丹

建立了气相色谱检测鳗鱼中残留的硫丹（包括α-硫丹和β-硫丹）的方法。鳗鱼样品经过提取、净化,采用气相色谱-电子捕获检测法进行硫丹含量的测定。α-硫丹和β-硫丹的检测低限均为1 μg/kg;α-硫丹和β-硫丹在2～50 μg/kg范围内其含量与峰面积呈现良好的线性关系,相关系数均为0.999;α-硫丹和β-硫丹在添加水平为1.0,2.0,5.0 μg/kg时,回收率分别为74%～89%和89%~98%,相对标准偏差为3.7%~7.2%和4.7%~8.7%。表明方法的重现性和准确性都非常好。     

分散液相微萃取-高效液相色谱法测定水中α-萘酚和β-萘酚

以氯苯为萃取剂,丙酮为分散剂,采用分散液相微萃取-液相色谱联用技术对水体中的α-萘酚和β-萘酚进行分析,优化了实验条件。该方法对α-萘酚和β-萘酚的线性范围分别为1.5～50μg/L和1.0～50μg/L,检出限分别为0.9μg/L和0.5μg/L,6次重复测定的相对标准偏差分别为3.3%和1.5%。方法应用于自来水、地下水和湖水样品的分析测定,回收率在91.3%～101.0%之间。     

蔬菜中多溴联苯醚的定量测定及其对人体的生物有效性

建立了以索氏抽提,凝胶渗透色谱及硅胶-氧化铝复合层析柱净化,测定蔬菜中13种多溴联苯醚(PBDEs)的GC-NCI MS分析方法,方法的检出限以干重计为5.4 ～15.7 pg/g,加标样品的回收率和RSD分别为78% ～97%和0.6% ～10.0%.还研究了蔬菜中的PBDEs在人胃肠中对人体的生物有效性,胡萝卜和菠菜中PBDEs的总含量分别为424.1 pg/g和981.3 pg/g,对人体的平均生物有效性分别为33.5%和2.6%,计算得到13种PBDEs在胡萝卜和菠菜中的生物有效含量分别为132.6 pg/g和26.1 pg/g,研究结果对污染物的暴露风险评估有参考价值.     

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.