在线液相-气相二维色谱高灵敏测定卷烟主流烟气中的4-（N-甲基亚硝胺基）-1-（3-吡啶基）-1-丁酮

建立了在线液相-气相二维色谱测定卷烟主流烟气中4-(N-甲基亚硝胺基)-1-(3-吡啶基)-1-丁酮(NNK)的方法。 NNK 的分析在在线凝胶气质联用仪上进行,采用自行装填的微型碱性氧化铝柱,并把仪器上的凝胶柱换成氧化铝柱,用于 NNK 的分析。捕集有主流烟气总粒相物的剑桥滤片用二氯甲烷提取,以 D4-NNK 为内标,提取液经微型氧化铝柱分离,含 NNK 的部位切割进入气相色谱,排干溶剂后启动气相色谱升温经毛细管柱进行分离,用质谱检测。本方法将烟气国标方法 NNK 测定中的氧化铝柱色谱净化和气相色谱-质谱分析在线连接起来,可不经样品前处理净化直接进样分析;每次进样可达40μL,是常规气相色谱-质谱分析最大进样量(2.0μL)的20倍,显著提高了分析灵敏度。方法线性范围达1.2~120 ng/ mL,相关系数为r=0.9998,回收率为93.9%~96.0%;检出限和定量限分别为0.25 ng/ mL 和0.9 ng/ mL,样品分析结果与中国烟草总公司企业标准方法进行对比,结果相符合。     

中心切割式多维气相色谱/质谱系统中中点限流器的改进及其在卷烟烟气中苯并[a]芘检测中的应用

对多维气相色谱的核心部件中点限流器进行了改进,用一段0.25mm i.d.毛细管柱取代石墨限流管,Y形玻璃压合连接器取代两孔石墨垫,显著提高了一维色谱保留时间的稳定性,保证了中心切割范围的准确性,且消除了石墨对苯并[a]芘的吸附残留。同时,将本系统应用于卷烟烟气中苯并[a]芘的检测。采用剑桥滤片捕集烟气粒相物,环己烷萃取,以氘代苯并[a]芘为内标,直接用中心切割式多维气相色谱/质谱(MDGC/MS)法测定。该法线性关系良好,其线性范围为1.47～29.4μg/L(r2=0.999 9);重复性好,测得实际样品中苯并[a]芘含量的相对标准偏差(RSD)为1.94%;回收率为90.74%～101.86%;检出限和定量限分别为0.31ng/支及1.03ng/支,可以满足检测要求。应用本系统对2R4F参比卷烟烟气中苯并[a]芘进行了检测,结果与文献报道值基本一致。     

固相萃取和气相色谱-质谱法测定主流烟气中苯并[a]芘的研究

提出了一种用于测定主流烟气中痕量苯并[a]芘的方法.以甲醇-正庚烷萃取体系初步处理主流烟气中的总粒相物(TPM),接着以KOH甲醇溶液数毫升洗涤正庚烷萃取液,再将正庚烷萃取液适当浓缩后经过酸化的硅胶固相萃取小柱,流出液用N2吹干后以乙酸乙酯200 μL定容,对苯并[a]芘进行选择离子监测方式下的气相色谱-质谱法定量测定.方法的分离效果及色谱重现性好,可用于复杂体系中痕量组分苯并[a]芘的定量测定.     

在线液相-气相二维色谱-质谱联用法测定烟用香精和料液中苯并[a]芘的含量

样品10.0g,加水10mL稀释,加0.100g·L-1 D12-苯并[a]芘内标溶液200μL,加环己烷10mL,以20 000r·min-1速率漩涡振荡萃取5min。提取液直接进入液相色谱,经微型硅胶柱分离净化,含苯并[a]芘的部位切割进入气相色谱,经毛细管柱分离后进入质谱分析,采用选择离子监测模式(SIM)进行测定。苯并[a]芘的质量浓度在0.08~50ng·L-1范围内与峰面积呈线性关系,方法的检出限(3s)为0.12ng·g-1,在3个不同浓度水平上进行了回收试验,回收率在92.7%~98.1%之间,测定值的相对标准偏差(n=7)在3.2%~3.7%之间。     

固相萃取新装置净化-超高效液相色谱法测定卷烟主流烟气中的苯并[α]芘

研究了用正相固相萃取净化,超高效液相色谱测定卷烟主流烟气中苯并[α]芘的方法。捕集有卷烟主流烟气总粒相物的剑桥滤片置于自主设计的样品萃取瓶中,用环己烷-乙醇(95:5,V/V)超声振荡萃取,提取液用硅胶固相萃取净化,然后以Waters ACQUITY UPLC BEH C18(2.1×50 mm,1.7μm)色谱柱为固定相,甲醇为流动相,超高效液相色谱-荧光检测测定;苯并[α]芘检出限为0.22 ng/支,样品加标回收率为89.6%~95.4%,日内相对标准偏差为3.2%,日间相对标准偏差为3.6%;结果令人满意。     

高效液相色谱法测定生活饮用水中的苯并[a]芘

建立高效液相色谱二极管阵列检测器检测生活饮用水苯并[a]芘的测定方法。采用C18反相色谱柱(150mm×4.6 mm,5μm),在流动相为甲醇–水(体积比为90∶10)、流量1.0 mL/min、检测波长295 nm、柱温35℃、进样体积20μL的条件下测定生活饮用水中苯并[a]芘。该方法检出限为6 ng/L,线性范围0～100 ng/mL,加标回收率为88.1%～93.4%,测定结果的相对标准偏差为1.06%(n=9)。该法样品预处理简单,分离度高,分析时间短,适用于生活饮用水中苯并[a]芘的准确定性定量测定。     

加速溶剂/固液固萃取-气相色谱/质谱法分析卷烟烟气中苯并[a]芘

建立了集萃取与净化于一体的加速溶剂/固液固萃取(AS/SLSE)卷烟烟气中痕量苯并[a]芘(BaP)的样品前处理方法。卷烟烟气经捕集后,用AS/SLSE提取和净化,萃取液浓缩后进行色谱分析。优化了AS/SLSE吸附剂、萃取温度、吹扫体积、静态萃取时间及循环次数等条件。在优化条件下(5 g硅镁型吸附剂、萃取温度100℃、吹扫体积40%、静态萃取时间3 min循环2次,样品连续萃取3次),AS/SLSE-气相色谱/质谱法(GC/MS)分析卷烟烟气中苯并[a]芘方法的检出限为1.0μg/L,回收率为97.1%,相对标准偏差(RSD)为2.5%。方法成功用于卷烟烟气样品的分析,测定结果与国家标准推荐方法吻合。     

全自动固相萃取-气相色谱-串联质谱法测定卷烟主流烟气中的3种多环芳烃

以全自动固相萃取技术净化主流烟气萃取液,建立了卷烟主流烟气中苯并［a］芘、苯并［a］蒽和屈艹 3种多环芳烃的气相色谱-串联质谱(GC-MS/MS)测定方法。以吸烟机抽吸卷烟,并以剑桥滤片捕集卷烟主流烟气,然后以含氘代苯并［a］芘内标的环己烷溶液萃取滤片,萃取液经全自动固相萃取仪净化后以GC-MS/MS分离检测。结果表明,苯并［a］芘、苯并［a］蒽和屈艹 的检出限分别为0.05、0.16和0.23 ng/cig,回收率为91.5%～102.1%,相对标准偏差(RSD)均小于5%。该方法的自动化程度高、操作简便、检出限低、重复性好,适用于卷烟主流烟气中苯并［a］芘、苯并［a］蒽 3种多环芳烃释放量的检测。     

气相色谱质谱法测定化妆品中9种多环芳烃

建立了气相色谱质谱法测定化妆品中9种多环芳烃的分析方法。化妆品中的萘、苯并[a]蒽、、苯并[b]荧蒽、苯并[j]荧蒽、苯并[k]荧蒽、苯并[e]芘、苯并[a]芘、二苯并[a,h]蒽等9种多环芳烃用甲醇超声提取后,用环己烷液-液萃取后浓缩,经硅胶-中性氧化铝柱净化后,采用气相色谱-质谱测定。多环芳烃浓度在0.05～2 mg/L范围内,质量浓度与其峰面积呈良好的线性关系。在低、中、高3个添加水平下,9种多环芳烃化合物的平均回收率为81.6%～100.2%,相对标准偏差为1.3%～5.8%。方法可用于化妆品中多环芳烃的检测。     

一种超临界流体色谱–气相色谱–质谱测定卷烟主流烟气中苯并[a]芘的方法

<正>申请公布号:CN106198796A申请公布日:2016.12.07申请人:云南中烟工业有限责任公司摘要本发明公开了一种超临界流体色谱(SFC)–气相色谱–质谱(GC–MS)测定卷烟主流烟气中苯并[a]芘的方法。本方法是在抽吸卷烟后,向捕集卷烟主流烟气总粒相物的滤片中加入内标物及环己烷溶液,超声提取后,萃取液用超临界流体色谱进行分离净化,切割含有苯并[a]芘的馏分再用GC–MS分析,根据目标物峰和同位素内标物峰的面积比定     

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.