采用计算化学方法解析苯和甲苯红外谱图

本研究应用量子计算化学软件Gaussian 03W HF方法中的3-21G基组优化苯和甲苯分子结构,预测苯和甲苯分子的红外光谱。找到苯环振动吸收峰分别是苯红外图中的1658 cm~(-1)与甲苯红外图中的1667 cm~(-1)。与苯和甲苯文献检索红外谱图相对应(特征吸收峰分别是1478和1485 cm~(-1)),符合较好。还找到苯环C-H拉伸振动吸收峰3080cm~(-1)(苯)和3040 cm~(-1)(甲苯)。能够实用于红外法检测环境中苯和甲苯。     

饮用水和地下水中多环芳烃的快速测定-气相色谱/质谱法

本文建立了液-液萃取和圆盘固相萃取-气相色谱/质谱法测定水质中苯并[k]荧蒽(BkF),苯并[a]芘(BaP),苯并[b]荧蒽(BbF),苯并[g,h,i]芘(BPR),茚苯[1,2,3-cd]芘(InP)的方法。圆盘固相萃取采用膜过滤片形成盘状结构,截面积增大,反压降低,可采用较高的流速,可防止堵塞问题。采用毛细管色谱柱分离,质谱采用选择离子扫描,减少了干扰物的影响,提高检测灵敏度。外标法定量,方法最低检出限(LOD)为:苯并[k]荧蒽,苯并[a]芘,苯并[b]荧蒽,苯并[g,h,i]芘,茚并[1,2,3-cd]芘分别为6ng/L。线性关系:浓度在2.5 ng/mL～62.5 ng/mL时相关系数r分别从0.9987～0.9994。在3个水平添加了(6.25 ng/L～62.5 ng/L)的回收测量(n=5),其回收率在83.71%～94.38%之间,相对标准偏差(RSD)为5.44%～15.54%。     

苯并荧蒽,苯并芘及其甲基同系物的初步定性

借助GC/MS法,笔者在海相中、古生界生油岩的芳烃馏分中检测到一个分子量为m/z 252 14n(n=0～3)的系列化合物。经与文献资料对比确认它属于烷基取代的苯并荧蒽和苯并[e]芘。在m/z 266质量色谱图上,最后流出的四个峰与甲基菲四个异构体的分布特征相似。经系统对比,初步确认它们属于甲基苯并[e]芘的异构体。     

质谱—质谱技术及其应用(二)

(三)应用举例近年来,用质谱—质谱技术所能分析的样品种类和数量迅速增长。在天然产物混合物分析方面,R.G.Cooks研究组直接分析了尿、蘑菇、古柯叶子、仙人掌属植物等。Mons研究组分析了复杂的海生甾醇混合物。Burlingame等人研究了与乙酰胺基酚共存的硫醚、游离二糖类和苯并[a]芘变型的双核甙酸系。Nibbering和Lev-     

皂甙化合物的氯加合负离子质谱研究

在质谱样品离子化过程中,由实验体系中存在的H 、Na 、K 等离子与样品分子结合而形成加合物离子,是一个普遍的现象.该现象也成为应用快原子轰击(FAB)、电喷雾(ESI)、基质辅助激光解吸电离(MALDI)等进行质谱分析时使样品得以离子化的基础.因此,在样品制备过程中,人为地加入某些碱金属或过渡金属的化合物作为离子化试剂,已成为提高信噪比,增强目标峰;抑制杂质峰,使样品得以检测的重要步骤[1,2].但是,目前人们利用和研究较多的是带正电荷的加合物离子,带负电荷的加合物离子却很少.本实验室在用电喷雾质谱负离子检测皂甙化合物时,发现Cl 等卤素负离子可以非常容易地与样品结合,形成带负电荷的[M X] 加合物离子.本工作拟对此进行较为详细的研究.     

气相色谱-串联四极杆质谱法测定主流烟气中的苯并[a]芘

为了给低焦油卷烟产品中的有害物质检测提供方法参考,本工作建立了卷烟主流烟气中苯并[a]芘的气相色谱-三重串联四极杆质谱联用测定方法。使用标准抽吸条件采集20支卷烟烟气粒相物,用含内标的环己烷超声萃取,经固相萃取净化后,以正离子多反应监测方式进样分析,内标法定量。方法经优化后,苯并[a]芘在0.4～20 μg/cig范围内具有良好线性,r²为0.999 92,定量限为0.073 μg/L,重复性变异系数最大为3.71%,加标回收率为95.7％～103.9％。该方法操作简便、流程短、溶剂用量少,尤其适合低焦油卷烟产品的苯并[a]芘检测。     

国内外造纸法烟草薄片的烟气主要有害物释放量研究及其烟气危害性评估

本文通过常规烟气化学与七种主要烟气有害物的分析,比较了一些有代表性的国内和国外加工进口造纸法烟草薄片产品的烟气特性与差异,并对这些样品的烟气危害性进行了评估。研究结果表明(:1)国内外造纸法烟草薄片的烟气均具有低焦油、抽吸口数、烟碱和低苯酚、HCN、苯并[a]芘、氨等有害物质释放量的特性;(2)国内外产品的烟气苯酚释放量基本低于烟丝一个数量级,但NNK的释放量较高;(3)国产造纸法烟草薄片虽具有更低总粒相物、焦油、烟气烟碱、水分的常规烟气特性,但因CO/焦油比值较高,又是其不足之处;(4)国产造纸法烟草薄片的苯酚、氨、及NNK释放量相对较低,而进口产品则表现为苯并[a]芘与CO释放量低;(5)烟气危害性指数计算与评估的结果表明,国产与进口造纸法烟草薄片的危害性大致相当,但均远低于烟丝,由此也证实造纸法烟草薄片是一种比卷烟烟丝"更加安全"的烟草配方原料。     

导数恒能量同步荧光光谱法快速检测蔬菜及谷物制品中的苯并(α)芘

结合导数恒能量同步荧光扫描技术,采用标准加入法定量检测,导数基线校正法处理数据,建立了一种蔬菜及谷物制品中苯并(α)芘的荧光快速检测方法。一般样品仅需简单超声萃取,深色蔬菜及在370 nm左右有干扰峰的谷物制品也只需增加微波皂化步骤,即可进行光谱扫描。对实际样品高(10μg/kg)、中(5.0μg/kg)、低(1.0μg/kg)浓度的加标回收率在84.2%~103.2%之间,方法重现性好,各类样品的检出限为0.17~0.55μg/kg,标准加入法工作曲线线性范围为0.034~50μg/L。该方法样品前处理简单,无需复杂的纯化分离步骤,适用于蔬菜及谷物制品中苯并(α)芘的快速分析测定。     

气相色谱-质谱法分析含羞草挥发油的化学成分

采用常规水蒸气蒸馏法提取含羞草中的挥发油，并用气相色谱-质谱法分析其化学成分。分离出41个峰，鉴定出34种化学成分，占总峰面积的89.01 %。含羞草挥发油中主要成分为N,N-二苯基-肼酰胺、邻苯二甲酸二异丁酯、邻苯二甲酸丁基-2-甲基丙基酯、十九烷、1H-吲哚-3-乙醇、二十四烷、2,4-二（1-苯乙基）苯酚、二十六烷、二十七烷等。     

三种紫苏子的红外光谱分析与鉴定

采用红外光谱三级鉴定法和整体解析法对来源地均为河北的三种紫苏子进行分析研究。结果显示:三种紫苏子样品红外光谱中,都有2927,2854,1745,1160 cm~(-1)附近表征油脂类的主要特征峰以及1655和1535 cm~(-1)附近表征蛋白质的主要特征峰。但三种紫苏子油脂与蛋白质特征峰的相对高度差异较大,说明二者在三种紫苏子中的相对含量不同。二阶导数红外光谱中,出现了1709 cm~(-1)附近属于有机酸类的特征峰;此外,三种紫苏子样品在1720~1530 cm~(-1)、1400~1020 cm~(-1)波段的谱峰有显著差异。二维相关红外光谱中,三种紫苏子样品在1400~1800 cm~(-1)、900~1300 cm~(-1)两个波段主要自动峰位置差异不大,不同之处在于自动峰间的相对强度。运用红外光谱三级鉴定和整体解析法可快速、全面分析鉴定三种紫苏子,为紫苏子种质鉴别和紫苏资源的开发利用提供研究思路和方法。     

环境致癌加合物MNU－DNA的高效液相色谱分离与质谱鉴别

本文报道环境致癌物ＭＮＵ与ＤＮＡ形成的ＭＮＵ－ＤＮＡ加合物的ＨＰＬＣ与ＭＳ的分离、鉴别结果。加合物在水解后分析。ＨＰＬＣ法通过保留时间及各洗提物的ＵＶ吸收光谱在线检测，筛选出感兴趣的目标化合物（Ｎ７－ＭＧ，Ｏ６－ＭＧ），再通过质谱（ＥＩＭＳ及ＦＡＢＭＳ）鉴定。文中还讨论了某些有关的质谱碎裂特征及温度对ＭＮＵ－ＤＮＡ加合物水解效率的影响     

抗抑郁化合物SIPI5358与α-,β-,γ-环糊精非共价复合物的研究

The non-covalent complexes of α-, β- or γ-cyclodextrin(α-, β- or γ-CD ) with piperazine derivative compound SIPI5358 were investigated by electrospray ionization mass spectrometry(ESI-MS) and UV spectrometry. The mass spectrometry results reveal that SIPI5358(guest) and α-, β- or γ-cyclodextrin(host) can be form 1:1 complexes in solution. The results obtained from ESI-MS are further confirmed by UV spectra.     

低聚壳聚糖钐配合物的制备及其与牛血清白蛋白的作用

合成了低聚壳聚糖和稀土离子Sm3＋的配合物,利用IR、UV—Vis和荧光光谱对配合物进行了表征。研究了低聚壳聚糖钐配合物与牛血清白蛋白（BSA）的相互作用。结果表明,BSA紫外吸收光谱随低聚壳聚糖钐配合物浓度的增加而增强,表现出明显的增色效应和较小的蓝移;低聚壳聚糖钐配合物对BSA的荧光具有猝灭作用。     

Detection and differentiation of biological species using microcalorimetric spectroscopy

We report on the application of infrared (IR) microcalorimetric spectroscopy ( micro -CalSpec) to the identification and detection of trace amounts of biological species. Our approach combines principles of photothermal IR spectroscopy with ultrasensitive microcantilever (MC) thermal detectors. We have obtained photothermal IR spectra for DNA and RNA bases and for Bacillus Cereus (an anthrax simulant) in the wavelength range of 2.5-14.5 micro m (4000-690 cm(-1)). The measurements are accomplished by absorbing biological materials directly on a MC thermal detector. The main advantage of the developed micro -CalSpec is its unprecedented sensitivity as compared to any of the previously explored IR techniques, including FTIR and photothermal FTIR methods. Our results demonstrate that <10(-9)g of a biological sample is sufficient to obtain its characteristic micro -CalSpec spectrum that contains information-rich chemical (vibrational) signatures. This opens up a new opportunity to create inexpensive high-throughput analytical systems for biochemical detection.     

椭圆型晶体谱仪谱测量的解谱研究

对椭圆型晶体谱仪配X射线CCD相机的X射线谱测量系统（EBCS-XCCD）进行了简要描述,研究了CCD相机记录信号的解谱处理方法,推出了对实测原始谱曲线辨认或标识值的计算公式及激光等离子体X射线源在某一波长光谱强度的公式,使之应用在激光打靶产生的等离子体源辐射X射线谱的回推,辨认出了激光等离子体X射线源能谱,并与文献[1]的结果进行了比较,结果基本一致。这一事实有力地佐证了解谱方法的可行性,也表明X射线CCD相机是适宜于椭圆型晶体谱仪的光谱测量记录。在已知晶体的积分反射率、滤片透射率和CCD探测效率的条件下,还可以获得X射线源光谱强度,可为下一步诊断激光等离子体的电子温度和离子密度的空间分布轮廓和进一步细化X激光研究奠定了更深厚的基础。     

Electron beam damage of amorphous synthetic polymers

The electron beam damage of amorphous polymers (PVC, PVDC, PTFE, PVDF, Hypalon, PES, Horizon and PDMS) has been measured by the elemental loss using EDX analysis. An attempt has been made to identify and eliminate the experimental error which would influence the measured decay curves. Only Cl and F in some polymers were found to be volatile. The PVC-Cl decay curves were compared with UV and IR spectra at different stages of irradiation and it has been concluded that some Cl is trapped in a more stable structure with conjugated double bonds. The formation of isolated double bonds and their destruction has been revealed by a staining technique for PVC, PMMA, PS and PC. It is likely that the mechanism of formation of isolated double bonds and their conversion to a more stable structure with conjugated double bonds is valid generally for all polymers. The staining peak can therefore be used as a universal technique for the beam sensitivity measurement.     

IR在新药沙纳唑结构确证中的应用

用IR对一类新药沙纳唑的化学结构进行确证,主要得到3403,3108,2995,1668,1555,1371和1145(cm~(-1))7个吸收峰,大部分是强的伸缩振动,分别代表分子结构中的-NH,=CH,-CH,-CONH,-NO_2(反称),-NO_2(对称)和-OCH_3官能团。结合NMR,UV,MS,X线衍射等测试结果,确证沙纳唑的结构式确实为N-(2-甲氧基乙基)-2-(3-硝基-1,2,4-三氮唑基-1-)乙酰胺。     

Fast magneto-optical spectrometry by spectrometer

Time efficient measurement of the spectroscopic magneto-optical (MO) activity of materials has always been desirable. In conventional MO systems, the monochromator produces quasi-monochromatic light in a narrow wavelength window. Therefore, to measure the spectroscopic MO activity, a large number of measurements over the full spectra is required to obtain satisfactory wavelength resolution and thus is very time consuming. Here, we develop a novel system that is capable of fast measurement of the MO activity by only one white light source, two polarizers, one achromatic quarter-wave plate, and one spectrometer. This system is flexible from UV to IR region, only depending on the power spectra of light source and sensitivity of the detector at the corresponding wavelengths. As examples, we measured the intriguing optic and MO activity in glass, ferromagnetic thin film, and bulk GaAs in the visible to near infrared region. The results of glass demonstrated a minimum resolvable Faraday rotation angle of 0.004° by the currently equipped system.     

Measuring the magnetic parameters of the multipole magnets for the specialized MLS source of synchrotron radiation

A metrology light source (MLS) is currently being constructed at the Physikalisch-Technische Bundesanstalt State Metrology Institute (Germany) for work in the range from IR to far UV radiation. The MLS system is composed of a storage ring with a circumference of 48 m for electrons with energies of up to 600 MeV and a 100-MeV microtron. The magnetic system of the storage ring contains 8 dipole magnets, 24 quadrupole magnets, 24 sextupole magnets, and 4 octupole magnets, all designed and produced by the Budker Institute of Nuclear Physics. The radial rotating coil method has been used in magnetic measurements of the multipole magnets. The measuring system is described, and the experimental results are presented.     

Mg(PO3)2-BaF2-AlF3系统玻璃的振动谱研究

应用红外及拉曼光谱研究了Mg(PO₃)₂-BaF₂-AlF₃系统氟磷玻璃的结构特征.证实了双键氧(P=O)及由Al(O.F)₄四面体和P(O.F)₄四面体所混合构成的网络结构存在于玻璃之中.在拉曼光谱中,V_Ba-F、V_Mg-F和V_Al-F振动吸收峰分别出现在480-510cm^-1、530-550cm^-1和580cm^-1处.根据红外及拉曼光谱的结果得出:随系统中氟化物含量的增加,玻璃结构逐渐由聚磷酸盐转变为焦磷酸盐和一氟正磷酸盐混合物,同时双键氧(P=O)消失.