气相法分析血浆中的全氟辛酸

 采用气相 电子捕获法测定了人血浆中全氟辛酸的含量。将血浆中的全氟辛酸酯化后进行分析 ,以全氟癸酸为内标。柱为HP 1熔融石英毛细管柱 (30m× 0 2 5mmi.d .× 0 2 5 μm)。方法的线性范围为 2 0 0 0μg/L～ 4 0 0× 10 3 μg/L ,线性相关系数r =0 994 6。平均回收率为 99 2 % ,相对标准偏差 (RSD)为 0 95 % ,血浆中全氟辛酸的检出限为 6 0 μg/L。方法准确、可靠 ,分析结果令人满意。     

反离子对全氟辛酸盐与高聚物的相互作用的影响

通过表面张力和电导率测定, 研究了全氟辛酸铵/四烷基铵(C7F15COON(CnH2n＋1)4, n＝0, 1, 2, 3, 4)与聚氧乙烯(PEO, 分子量20000)和聚氧乙烯聚氧丙烯三嵌段共聚物(Pluronic F68)的相互作用. 结果表明, 对PEO-C7F15COON(CnH2n＋1)4混合体系, 只有全氟辛酸铵、全氟辛酸四甲铵与PEO之间有明显的相互作用. 对F68-C7F15COON(CnH2n＋1)4混合体系, 只有全氟辛酸四丁铵未发现与F68有明显的相互作用. 说明全氟辛酸盐的反离子越大, 其与高聚物间的相互作用越弱. 增加高聚物的疏水性可以增强表面活性剂与高聚物的相互作用.     

利用代谢组学技术研究全氟辛酸的人肝脏毒性机制

采用超高效液相色谱-飞行时间质谱联用系统研究暴露于不同浓度全氟辛酸(PFOA)72 h的正常人L-02肝细胞内代谢谱的变化。将主成分分析法用于数据分析和生物标志物的初步筛选。在正离子和负离子扫描模式下,对照组和暴露组均可得到较好区分并呈现出明显的剂量-效应关系,筛选鉴定了18种与全氟辛酸毒性密切相关的潜在生物标志物,包括肉碱和酰肉碱、核苷及其同源物、氨基酸及其同源物等。在暴露组中,在脂肪酸代谢中起关键作用的肉碱类代谢物的含量变化显著,其中肉碱含量随剂量的升高呈现明显的下降趋势,而酰肉碱则呈现相反的变化趋势,表明全氟辛酸可通过诱导胆固醇等脂类物质代谢相关基因的异常表达从而扰乱胆碱类物质的正常合成和代谢。除了变化最显著的胆碱代谢通路之外,全氟辛酸的肝脏毒性还与三羧酸循环、嘌呤代谢、氨基酸代谢和核酸代谢等多个通路相关。这些结果表明,PFOA在体内经过长时间累积可通过干扰众多的代谢通路从而破坏人体的正常生理机能,造成潜在的健康危害。     

全氟辛酸铵与全氟壬酸铵混合物的表面活性

测定了全氟辛酸铵和全氟壬酸铵及其不同比例混合物的0.1mol/L氯化铵水溶液表面张力曲线。讨论了它们的胶团化作用、吸附作用和降低水表面张力的能力。改进了Ingram-Luckhurst自单一表面活性剂活性张力曲线得到混合溶液表面张力曲线的方法。     

液相色谱-串联质谱法同时测定婴幼儿配方乳粉中全氟辛酸、全氟辛烷磺酸、双酚A和壬基酚残留

建立了婴幼儿配方乳粉中全氟辛酸、全氟辛烷磺酸、双酚A和壬基酚多残留的高效液相色谱-串联四极杆质谱联用测定方法。样品用水超声溶解,乙腈沉淀蛋白质,液相色谱-串联质谱测定,基质内标法定量。以Hypersil GOLD C₁₈色谱柱（50 mm×4.6 mm,1.9 μm）分离,流动相为30 mmol/L乙酸铵水溶液和甲醇,流速0.30 mL/min。在该优化条件下,全氟辛酸、全氟辛烷磺酸、双酚A和壬基酚的定量限分别为0.5、1.0、10.0和5.0 μg/kg,方法回收率为86.1%~106.8%,相对标准偏差为2.87%~9.53%。测定了多种市售婴幼儿配方奶粉,表明该方法操作简单、测定结果准确,可用于婴幼儿配方奶粉中全氟辛酸、全氟辛烷磺酸、双酚A和壬基酚多残留的同时快速测定。     

酶促合成全氟辛酸半乳糖脂

首次报道了酶促合成含氟糖脂。在IM-60脂肪酶催化下以85%产率得到了全氟辛酸半乳糖脂。     

离子液体分散液液微萃取-超高效液相色谱-串联质谱法测定食品接触材料中全氟辛酸和全氟辛烷磺酸的迁移量

建立了一种基于离子液体分散液液微萃取前处理技术的食品接触材料中全氟辛酸和全氟辛烷磺酸迁移量的超高效液相色谱-串联质谱测定方法。水、10%（体积分数）乙醇溶液和4%（体积分数）乙酸溶液作为3种水性食品模拟物与食品接触材料充分接触,进行迁移试验,对迁移液采用离子液体分散液液微萃取技术进行目标物的萃取富集,考察了萃取剂种类和用量、涡旋时间、盐浓度、离心速率及时间等关键因素对食品模拟物中全氟辛酸和全氟辛烷磺酸萃取效率的影响。使用Waters ACQUITY UPLC BEH Shield RP18色谱柱（50 mm×2.1 mm,1.7 μm）,以乙腈和水为流动相,梯度洗脱分离,在电喷雾负离子模式下,采用多反应监测模式进行定性及定量分析。结果表明,全氟辛酸和全氟辛烷磺酸在各自范围内线性关系良好（r²>0.99）,检出限分别为0.5和1 μg/L,定量限分别为2和5 μg/L;在低、中、高3个添加水平下全氟辛酸和全氟辛烷磺酸的平均回收率为86.4%~116.9%,相对标准偏差为4.3%~14.4%（n=6）。该方法准确高效、环境友好,适用于食品接触材料中全氟辛酸和全氟辛烷磺酸迁移量的检测。     

全氟烷基磺酰卤化学

本文介绍了全氟烷基磺酰卤化学的现状和进展,并对全氟烷基磺酰氟、磺酰氯、磺酰溴、磺酰碘的制备,特性,反应性及应用作了比较与论述,得到了一定的规律性。     

欧盟可能限制使用全氟辛酸及相关物质

<正>德国与挪威合作,计划于2014年10月17日就全氟辛酸提交一份文件,称为《附件XV限制资料文件》。该份文件根据《化学品注册、评估、授权和限制法规》(REACH法规)附件XV内的相关资料规定汇编而成。2014年3月5日,欧洲化学品管理局(ECHA)宣布,德国与挪威政府已展开一项资料收集工作,以确定全氟辛酸及     

纺织品中全氟辛酸及全氟辛磺酰基化合物的气相色谱-μECD测试方法

建立了超声波辅助萃取-气相色谱-微电子捕获检测器测定纺织品中全氟辛酸(PFOA)及全氟辛磺酰基化合物(PFOS)的方法。通过单因子选择实验、正交实验等方法建立了纺织品中PFOA和PFOS的超声波萃取方法和PFOA的衍生反应条件。并采用加大流速和降低温度的方法,实现了3种PFOA和PFOS混合物的气相色谱分离及测试。方法的检测限为0.00591~0.02319μg/g;精密度为2.1%~9.7%;加标回收率为92.2%~101.9%。方法适用于纺织品中痕量PFOA和PFOS的监测分析。     

二氧化碳和丙烯直接合成甲基丙烯酸的NiPMo/TiO2催化剂的研究

用溶胶-凝胶法以磷钼酸(MPA)的镍盐溶液水解钛酸四丁酯制备了NiPMo/TiO2催化剂.使用ICP、 XRD、 TG-DTA、 IR、 TPD-MS和微反应技术研究了催化剂的化学组成、热稳定性、化学吸附性质和催化反应性能.杂多钼酸盐与TiO2通过O2-在TiO2表面发生了键合.在623 K下,杂多阴离子仍保持原有的Keggin结构.CO2在Lewis酸位Ni(Ⅱ)和Lewis碱位Ni-O-Mo的桥氧协同作用下生成CO2卧式吸附态Ni(Ⅱ)←O-(CO)←(O--Ni).丙烯有多种吸附态在催化剂上吸附.在563 K、 1 MPa和空速1500 h-1的反应条件下,丙烯的摩尔转化率为3.2%,产物MAA选择性为95%.     

Toward new camptothecins. Part 6: Synthesis of crucial ketones and their use in Friedländer reaction

In the context of the preparation of camptothecin and luotonin A analogs, the synthesis of some key keto-precursors and their use in Friedländer condensation are described. This paper also focuses on the stability of these keto intermediates and emphasizes the major differences between indolizinones and pyrroloquinazolinones series. Noteworthy is also the report of some original structures isolated as by-products of some experiments.     

CoFe2O4自形成磁性液体场致结构化对磁化的影响

The Langevin paramagnetic theory can’t describe the relation between magnetization of ferrofluids and applied magnetic field. The structuralization of ferrofluids, which is considered the main influence factor of the magnetization, is regarded. The part of magnetization works is deposited when the structure is forming. This action influences the magnetization of ferrofluids directly or indirectly. On the base of the “compressing” model, the Langevin function that usually describes the magnetization of ferrofluid is modified, and a well-fitted curve is obtained. An equation of the relation between the equivalent volume fraction after being “compressed” and the intensity of magnetic field is discovered, which approximately describes the process of magnetization. The relation between the approximate initial susceptibility and the volume fraction can be obtained from modified formula.     

Highly regioselective Buchwald–Hartwig amination at C-2 of 2,4-dichloropyridine enabling a novel approach to 2,4-bisanilinopyridine (BAPyd) libraries

The highly regioselective Buchwald–Hartwig amination at C-2 of the cheap and readily accessible reagent, 2,4-dichloropyridine with a range of anilines and heterocyclic amines is described. This new methodology is robust and provides a facile access to 4-chloro-N-phenylpyridin-2-amines on 0.25 mol scale. These intermediates undergo a further Buchwald–Hartwig amination at higher temperature to enable rapid exploration of the chemical space at C-4 and to provide a library of 2,4-bisaminopyridines.     

KMnO4-mediated oxidative CN bond cleavage of tertiary amines: Synthesis of amides and sulfonamides

KMnO₄-mediated oxidative CN bond cleavage of tertiary amines producing secondary amine was introduced, which was trapped by electrophiles (acyl chloride and sulfonyl chloride) to form amides and sulfonamides. The reaction could take place at mild condition, tolerating a wide range of function groups and affording products in moderate to excellent yields.     

Chemistry of heterocyclic compounds at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences, over 50 years (Review)

The review contains a concise historical account and information on the most significant researches undertaken by the staff at the A. E. Favorsky Irkutsk Institute of Chemistry, Siberian Branch of the Russian Academy of Sciences on the Chemistry of Heterocyclic Compounds. Dedicated to Academician of the Russian Academy of Sciences B. A. Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1443–1502, October, 2008.     

Sulfur-directed metal-free and regiospecific methyl C(sp3)–H imidation of thioanisoles

Regiospecific and direct imidation of the methyl C(sp³)–H bond of thioanisoles is realized under mild and metal-free conditions with N-fluorobis(benzenesulfonyl)imide as an oxidant and nitrogen source. Proposed mechanism suggests that thionium ion intermediates and a Pummerer-type reaction are involved. The imidation has advantages such as high step-economy, excellent functionality tolerance, and regiospecificity, giving structurally diverse imidation products.     

Selective syntheses of 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones via temperature-dependent Rh(II)-carbenoid-mediated 2H-azirine-ring expansion

The Rh(II)-catalyzed reaction of 2-carbonyl-substituted 2H-azirines with ethyl 2-cyano-2-diazoacetate or 2-diazo-3,3,3-trifluoropropionate provides an easy access to 2H-1,3-oxazines and 1H-pyrrol-3(2H)-ones. These compounds can be selectively prepared from the same starting material using temperature as the only varied parameter. The 2-azabuta-1,3-diene intermediate, a common precursor for both heterocyclic products, isomerizes into 2H-1,3-oxazine under kinetic control, while 1H-pyrrol-3(2H)-one is the sole product of the reaction at elevated temperatures. According to DFT-calculations a one-atom oxazine ring contraction involving ring-opening to a 2-azabuta-1,3-diene intermediate, followed by a 1,5- and 1,2-prototropic shift leads to the consecutive formation of imidoylketene and azomethine ylide, which then further undergo cyclization to the pyrrole derivative.     

Synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives

Different approaches for the synthesis of 1-benzyloxypyrazin-2(1H)-one derivatives from simple amino acids have been investigated. A library of 33 precursors for the preparation of N-hydroxy pyrazinones was obtained in moderate to good yields.