固相萃取结合气相色谱-质谱法测定皮革中的14种阻燃剂

采用固相萃取结合气相色谱-质谱(GC-MS)技术,建立了皮革中14种多氯联苯及磷酸三酯类阻燃剂(TEP,TBP,TCEP,PCB18,TCPP,PCB101,PCB153,PCB138,TPh P,TEHP,PCB180,o-TTP,m-TTP,p-TTP)的高通量检测方法。皮革样品经乙腈超声提取后,采用Florisil固相萃取柱净化,经DB-5MS色谱柱分离,GC-MS的选择离子监测(SIM)模式监测,以保留时间和特征离子比值定性,外标法定量。14种阻燃剂在一定浓度范围内线性关系良好,相关系数(r2)均大于0.998,方法检出限为25.0~50.0μg/kg,平均回收率为82.0%~112.8%,相对标准偏差(RSD,n=6)为2.1%~9.4%。方法的前处理简单快速,灵敏度高,适用于皮革中14种阻燃剂的同时测定。     

凝胶渗透色谱柱去脂-气相色谱-质谱法测定人血清中新型卤系阻燃剂

建立了凝胶渗透色谱(GPC)去脂,气相色谱-负化学电离源-质谱(GC-NCI-MS)法测定人血清中2,2’,4,4’,5,5’-六溴联苯(BB-153)、1,2-二(2,4,6-三溴苯氧基)乙烷(BTBPE)和德克隆(Dechlorane plus,DP,包括syn-DP和anti-DP)的方法。人血清样本加入内标13C12BB-153和13C10syn-DP,经蛋白质变性、脂肪提取、GPC去脂、酸性硅胶柱净化后,利用气相色谱-负化学电离源-质谱法测定样品中BB-153,BTBPE,syn-DP和anti-DP,监测离子分别为m/z 627.5,629.5,m/z 79,81以及m/z 652,654。结果表明,13 C12 BB-153和13 C10syn-DP的血清加标回收率分别为91.5%±8.9%和92.3%±8.1%,检出限为0.6～1.2 ng/g脂肪。应用本方法对人血样品进行测定,BB-153和BTBPE在所有样本中均未检出,syn-DP和anti-DP的浓度范围分别是0.7～9.2 ng/g脂肪和0.6～2.0 ng/g脂肪。     

加速溶剂萃取-固相萃取净化-气相色谱/质谱法测定沉积物中多氯联苯和多环芳烃

建立了加速溶剂萃取-固相萃取净化-气相色谱/三重四极杆串联质谱联用(ASE-SPE-GC-QqQ-MS/MS)法同时测定沉积物中28种多氯联苯(PCBs)和16种多环芳烃(PAHs)。对萃取、净化及仪器分析条件进行了优化。优化条件为:ASE萃取温度90℃,萃取时间6 min;净化小柱为硅胶-Florisil固相复合柱(填料自下而上为弗罗里硅土、0.7 g活化硅胶、1 g无水硫酸钠);洗脱溶液为丙酮-正己烷(1∶19,V/V)混合溶液,洗脱速率为0.6 mL/min。PCBs和PAHs在2～500μg/L和5～1000μg/L浓度范围内的线性相关系数(R2)分别为0.9987～0.9999和0.9939～0.9999;PCBs和PAHs方法检出限分别为0.001～0.08 ng/g和0.07～0.45 ng/g;定量限为0.003～0.25 ng/g和0.24～1.67 ng/g;实际样品平均加标回收率为95.6%～125.7%和70.4%～124.7%;方法相对标准偏差(n=6)为0.7%～6.4%和1.1%～12.8%。运用本方法对滇池入湖河口表层沉积物样品进行测定,该区域PCBs单体浓度为n.d.(未检出)～0.13 ng/g,PAHs单体浓度为0.79～131.12 ng/g。     

凝胶渗透色谱净化-气相色谱-质谱法同时测定金银花中33种农药残留组分

建立了凝胶渗透色谱(GPC)净化、气相色谱-质谱(GC-MS)同时测定金银花中33种有机氯、有机磷和拟除虫菊酯农药残留的方法.样品中的待测农药组分经乙酸乙酯-环己烷混合溶剂(1∶ 1, V/V)提取、GPC净化去除色素等杂质,GC-MS采用全扫描/选择离子监测模式(Scan/SIM)采集数据后进行定性/定量分析.方法的相对标准偏差(RSD)≤16.70 %(6.9～84.6 ng/g,n=5);5种不同加标浓度下,待测农药的标准加入回收率在57.4%(甲胺磷)～109.9%(马拉硫磷)之间;各农药组分的定性检出限(3σ)为0.10～10.5 ng/g,定量检出限(10 σ)为0.33～20.0 ng/g.     

气相色谱–质谱法快速测定塑料中磷酸三甲苯酯异构体

建立了气相色谱–质谱联用法,用于测定塑料材料中3种磷酸三甲苯酯同分异构体磷酸三邻甲苯酯、磷酸三间甲苯酯、磷酸三对甲苯酯。采用30℃/min升温速率,3种磷酸三甲苯酯同分异构体均在10 min内出峰,质量浓度在0.0~2.4 mg/L范围内与色谱峰面积呈良好的线性关系,相关系数不小于0.999 0,检出限均为0.1μg/L,加标回收率为90.6%~108.2%,测定结果的相对标准偏差为0.6%~4.8%(n=4)。该方法灵敏度高,精确度满足检测要求。     

固相萃取-气相色谱-质谱法测定土壤中阿特拉津

应用固相萃取-气相色谱-质谱法测定土壤中阿特拉津的含量。土壤样品采用索氏提取,硅胶固相萃取小柱净化。在气相色谱分离中用TR-5MS色谱柱为固定相,在质谱分析中采用选择离子检测模式。阿特拉津的质量浓度在5.00~200μg·L-1范围内与其峰面积呈线性关系,检出限为0.32ng·g-1。加标回收率在88.2%~90.7%之间,测定值的相对标准偏差(n=10)为4.8%。     

凝胶渗透色谱-高效液相色谱-串联质谱法同时测定烟草中3种抑芽剂残留

建立了用凝胶渗透色谱净化-液相色谱-串联质谱分析烟草中3种抑芽剂残留的方法。卷烟中的待测抑芽剂组分用V(乙酸乙酯)∶V(环己烷)=1∶1超声提取后通过凝胶渗透色谱净化;凝胶色谱柱为Biobeads S-X3玻璃柱(50 g,400 mm×25 mm),流动相为V(乙酸乙酯)∶V(环己烷)=1∶1溶液,流速5 mL/min;收集第10~25 min流出的液体用液相色谱色谱-三重四极杆串联质谱仪测定。在0.5~100 ng/mL的质量浓度范围内,各种抑芽剂标准溶液的线性相关系数均大于0.99。在样品中添加3种抑芽剂(添加水平为5,20,100μg/kg)的混合标准溶液,平均回收率在86.2%~108.4%之间,3种抑芽剂的RSD在1.1%~7.5%之间;方法的检测限在0.01~0.06μg/kg之间。     

气相色谱-质谱法测定温室大棚土壤中13种有机磷酸酯

该文建立了气相色谱-质谱法(GC-MS)检测温室大棚土壤中磷酸三乙酯、磷酸三丙酯、磷酸三正丁酯、磷酸三异丁酯、磷酸三丁氧乙酯、磷酸三(2-乙基己基)酯、磷酸三(2 氯乙基)酯、磷酸三(1 氯 2-丙基)酯、磷酸三(1,3-二氯-2-丙基)酯、磷酸三苯酯、磷酸三甲苯酯、磷酸甲苯二苯酯、2 乙基己基二苯基磷酸酯13种有机磷酸酯（OPEs）的分析方法,并优化了提取溶剂、提取方式、提取时间、萃取柱种类和色谱条件等实验参数。样品以正己烷-丙酮(体积比1∶1)为提取溶剂超声提取,经Florisil固相萃取柱净化,再采用气相色谱-质谱法(选择离子监测模式)检测,内标法定量。结果显示：13种化合物在1~500 μg/L质量浓度范围内线性良好,相关系数(r2)为0.999 3~0.999 7,检出限(LOD,S/N=3)为0.04~2.31 μg/L,定量下限(LOQ,S/N=10)为0.13~7.69 μg/L,在3个加标浓度(1.0、10、50 μg/L)下的回收率为54.5%~130%,相对标准偏差(RSD)为1.7%~9.9%。采用该方法对北京地区温室蔬菜大棚中41份土壤样品进行分析发现,除磷酸三丙酯(TPrP)外,其余12种OPEs均有检出,含量为1.90~632 ng/g(干重),平均值为87.8 ng/g,中位值为39.7 ng/g。其中磷酸三丁氧乙酯(TBEP)是温室土壤中最主要的OPEs,约占12种有机磷酸酯总含量(∑12OPEs)的20%。该方法操作简便、快速、精密度良好,可用于土壤中13种OPEs的测定。     

凝胶渗透色谱结合气相色谱-负化学源质谱法分析鱼肉及鱼油中的多溴联苯醚和得克隆阻燃剂

建立了凝胶渗透色谱(GPC)结合气相色谱-负化学源质谱(GC-NCI/MS)检测鱼肉及鱼油中8种多溴联苯醚(PBDEs)同系物及2种得克隆阻燃剂(DP)的分析方法。试样中加入内标物BDE-77和13C12-BDE-209后进行索氏提取,提取液经自动GPC系统除脂,多层硅胶层析柱净化后,在15 m长的毛细管气相色谱柱上分离,NCI/MS以选择离子监测方式检测目标化合物。以鱼肉样品为基质,当PBDEs的加标水平为0.2 ng/g和2 ng/g、BDE-209和DP的加标水平相应提高10倍时,其平均加标回收率为71.1%～121.4%,相对标准偏差为2.96%～13.31%(n=5);以信噪比(S/N)为3计算方法的检出限(LOD)为2.2～39.8 ng/kg。用该方法检测市售鱼肉及鱼油样品,其中多溴联苯醚总含量为2.18～15.93 ng/g,以BDE-209、BDE-47为主,两种DP均未检出。该方法准确、灵敏度高,能够满足富含脂质的动物性样品中痕量DP和PBDEs残留的分析要求。     

凝胶渗透色谱结合气相色谱-负化学源质谱法分析鱼肉及鱼油中的多溴联苯醚和得克隆阻燃剂

建立了凝胶渗透色谱(GPC)结合气相色谱-负化学源质谱(GC-NCI/MS)检测鱼肉及鱼油中8种多溴联苯醚(PBDEs)同系物及2种得克隆阻燃剂(DP)的分析方法。试样中加入内标物BDE-77和13C12-BDE-209后进行索氏提取,提取液经自动GPC系统除脂,多层硅胶层析柱净化后,在15 m长的毛细管气相色谱柱上分离,NCI/MS以选择离子监测方式检测目标化合物。以鱼肉样品为基质,当PBDEs的加标水平为0.2 ng/g和2 ng/g、BDE-209和DP的加标水平相应提高10倍时,其平均加标回收率为71.1%～121.4%,相对标准偏差为2.96%～13.31%(n=5);以信噪比(S/N)为3计算方法的检出限(LOD)为2.2～39.8 ng/kg。用该方法检测市售鱼肉及鱼油样品,其中多溴联苯醚总含量为2.18～15.93 ng/g,以BDE-209、BDE-47为主,两种DP均未检出。该方法准确、灵敏度高,能够满足富含脂质的动物性样品中痕量DP和PBDEs残留的分析要求。     

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.     

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.     

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.     

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.     

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.     

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.     

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.