同步荧光光谱法监测按芳环数分离重质油中的芳烃

采用同步荧光光谱法监测了液相色谱法以氧化铝作固定相将重质油中的芳烃按芳环数分离的分离过程。在同步荧光光谱的监测下，选择了液相色谱分离的合适进样量和分段梯度洗脱溶剂强度，使得减压馏分油和减压渣油中的芳烃都可较好地按芳环数进行分离。     

水溶性杯芳烃对染料客体分子的包结配位作用

研究了水溶性的杯[n]芳烃磺酸盐(n=4,6,8)及杯[6]芳烃磺酸盐的烷基化衍生物在25.0℃对几种染料客体分子的包结配位作用,发现杯[n]芳烃磺酸盐均使客体的荧光强度降低,而在其下缘的烷基化衍生物却使客体的荧光强度增强,从光物理行为对这些结果进行了解释。由荧光光谱分光光度滴定技术确定了25.0℃时所形成配合物的稳定常数,讨论了其分子识别性质。     

去叔丁基杯[8]芳烃乙酸钠对紫杉醇包合作用的研究

采用紫外分光光度法和荧光光谱法研究去叔丁基杯[8]芳烃乙酸钠对紫杉醇的包合和释放过程,考察了二者物质的量之比、温度等因素对包合作用的影响.结果显示去叔丁基杯[8]芳烃乙酸钠在一定条件下与紫杉醇可形成稳定的超分子包合物,包合后水溶性明显提高,且随着去叔丁基杯[8]芳烃乙酸钠/紫杉醇物质的量之比的增加,荧光强度明显增强.去叔丁基杯[8]芳烃乙酸钠今后有望成为紫杉醇类抗肿瘤药物的良好载体.     

基于杯[6]芳烃的选择性识别氟离子和丙二酸的荧光传感器

以杯[6]芳烃为平台, 通过在上沿用氨基吡啶桥连的方法固定构象, 并以氨基吡啶基团为识别位点和荧光基团, 合成了一类能识别F－和丙二酸的新型荧光化学传感器. 当氟离子与胺成氢键时, 由于光诱导电子转移效应(PET), 荧光强度淬灭; 但往这个配合物滴加丙二酸时, 荧光强度得到迅速恢复, 由此, 传感器体现了一个on/off的分子开关性质.     

在线富集高效液相色谱法测定饮用水中的多环芳烃

1　　引　　言多环芳烃是一类重要的致癌物质 ,环境样品中痕量的多环芳烃分析具有重要意义。其中高效液相色谱 程序波长荧光检测器检测是测定多环芳烃最常用的方法。紫外二极管矩阵检测器具有检验峰纯度、比较未知光谱与谱库光谱辅助定性的功能 ,其检测结果可靠性比程序波长荧光检测器高。但是紫外检测器灵敏度比荧光检测器低近两个数量级 ,对于清洁水样 ,多环芳烃含量很难达到紫外检测器的定量范围。为了解决清洁水样中多环芳烃的紫外二极管矩阵检测器检测 ,我们研究了色谱柱在线富集的方法 ,大大提高了多环芳烃的富集倍数 ,清洁水样中多…     

近红外光谱法测定成品汽油中的芳烃和烯烃含量

介绍了近红外光谱测定90#汽油及93#汽油中芳烃和烯烃含量。选择1100～1300nm的近红外光谱域,在荧光指示剂吸附法的基础上,采用偏最小二乘法建立了适合测定90#汽油及93#汽油中芳烃和烯烃含量的分析模型,通过大量试验对所建分析模型的可靠性进行了验证。近红外光谱法的测定结果与荧光指示剂吸附法的测定结果具有很好的一致性。与荧光指示剂吸附法相比,近红外光谱法可以提高分析效率,降低分析成本,具有较高的分析精密度。     

气相色谱法测定催化裂化汽油的烃族组成

在国产仪器和设备上建立了气相色谱法分析催化裂化汽油烃族组成的分析方法。采用N,N-双(a-氰乙基)甲酰胺为固定液的色谱柱将样品中的非芳烃和芳烃分离。以水润湿氮气来稳定高氯酸-高氯酸汞吸收剂,这种吸收剂对烯烃显示了良好的吸收选择性。方法通过两次进样计算出饱和烃、烯烃、芳烃含量。一次进样的分离时间在10分钟左右。与荧光色谱法相比本方法有更好的准确度与重复性。     

双水相萃取-液相色谱法检测人尿中的羟基多环芳烃

建立了乙腈-(NH4)2SO4双水相提取,液相色谱-荧光法同时检测人尿中10种羟基多环芳烃的分析方法。尿样中结合态的羟基多环芳烃用β-葡萄糖苷酸酶-芳基硫酸酯酶缓冲液(pH 5.0)于37℃下恒温震荡4 h后,以乙腈-硫酸铵双水相提取富集、净化,采用ZORBAX Eclipse C18色谱柱分离,流动相为乙腈-水,梯度洗脱,荧光检测器检测,外标法定量。方法用有机化合物激发光谱和发射光谱的"镜像"关系确定并优化了化合物的激发波长和发射波长,讨论了无机盐、萃取剂的选择以及pH、离子强度、乙腈析出体积、静置时间、甲醇含量等对测定的影响。10种羟基多环芳烃线性范围为5.00～200.00 ng/mL,相关系数大于0.999,平均回收率为43.6%～94.4%,相对标准偏差为4.2%～9.2%,检出限为0.06～2.32 ng/mL。方法可用于尿中10种羟基多环芳烃的测定。     

一种新型含喹啉环杯[4]芳烃衍生物的合成

以对叔丁基苯酚为起始原料,把酯基和具有荧光性质的喹啉环引入杯芳烃大环分子中,通过缩合,两步取代反应,获得了具有荧光性质的新型含喹啉环杯[4]芳烃衍生物。其结构经1H NMR,IR,MS和元素分析表征。     

偶氮苯光色基元修饰的杯芳烃的荧光性能和液晶行为

偶氮苯光色基元修饰的杯芳烃的荧光性能和液晶行为;偶氮苯;杯［４］芳烃;热致液晶;荧光     

Laser-based detection of PAHs and BTXE-aromatics in oil polluted soil samples

Time-resolved laser-induced fluorescence spectroscopy and fiber optics are applied for the detection of aromatic hydrocarbons in oil contaminated water and soil samples. Time-integrated data accumulation of fluorescence intensities in an "early" and in a "late" time window with respect to the exciting laser pulse simplifies the method in such a way that it becomes very attractive for practical applications. For ultraviolet laser excitation at 337 nm and recording fluorescence signals at 400 nm, typical detection limits of the present set-up are 0.5 mg engine oil/L in water and 5 mg engine oil/kg in soil. A discrimination between BTXE-aromatics and PAHs in oil polluted soil or water samples is possible, when more than one laser wavelength in the ultraviolet is used for the excitation. The possibilities for a thermal discrimination between different aromatics are also discussed.     

UV absorption and fluorescence properties of fused aromatic hydrocarbons having trimethylsilyl, trimethylgermyl, and trimethylstannyl groups

Effects of trimethylsilyl, trimethylgermyl, and trimethylstannyl substituents attached to fused aromatic hydrocarbons such as pyrene, anthracene, phenanthrene, and naphthalene were studied in terms of UV absorption and fluorescence properties in aerated cyclohexane solutions. Absorption maxima of trimethylsilyl-, trimethylgermyl-, and trimethylstannyl-substituted aromatic hydrocarbons shifted to longer wavelengths than those of unsubstituted ones. Absorption maxima of mono-, bis-, tris-, and tetrakis(trimethylsilyl)pyrenes shifted to longer wavelength consecutively at intervals of 10 nm. Fluorescence intensities and fluorescence lifetimes of trimethylsilyl-substituted aromatic hydrocarbons were larger and longer than those of unsubstituted ones, and they decreased in the order of Me₃SiAr > Me₃GeAr > Me₃SnAr. Fluorescence intensity of 1,3,6,8-tetrakis(trimethylsilyl)pyrene was largest among those of a series of mono-, bis-, tris-, and tetrakis(trimethylsilyl)pyrenes under aerated conditions.     

Total synchronous fluorescence scan spectra of petroleum products

Extending the two-dimensional synchronous fluorescence scan to a three-dimensional total synchronous fluorescence scan (TSFS) spectral measurement gives the total synchronous fluorescence characteristics of a multifluorophoric sample at various possible wavelength intervals (Deltalambda), which could help to characterize multifluorophoric systems better. TSFS spectra of petroleum products such as diesel, kerosene, petrol, engine oil etc., available in the Indian market, are reported. Fluorescence in these samples is due to the presence of polycyclic aromatic hydrocarbons (PAHs) of various ring sizes. The TSFS contour plot profiles of the neat samples measured at right-angle geometry is a result of various energy-degrading photophysical processes such as inner filter effect, light attenuation, resonance energy transfer, collisional quenching etc. TSFS plots make it easy to obtain the optimized Deltalambda of an unknown sample of analytical interest. TSFS and the excitation-emission matrix (EEM) techniques are similar, but the contour profiles generated are different. The response of the TSFS contour profiles to dilution is different from that in the EEM contour profiles. Thus, TSFS can provide an alternative way of presenting the fluorescence response of concentrated multifluorophoric samples.     

Characterization of polycyclic aromatic hydrocarbons in shale oil by chromatography and fluorescence densitometry

Polycyclic aromatic hydrocarbons (6-, 5-, 4- and 3-ring) were characterized in several shale oil samples. Open-column, dry-column and thin-layer chromatography were used in the separation steps. Visible fluorescence from the separated components on chromatoplates was measured directly to obtain fluorescence profiles of the distribution on the chromatoplates. The methods developed are inexpensive, reproducible, and allow rapid characterization of polycyclic aromatic hydrocarbons in shale oil samples.     

Fluorescence quenching mechanisms of aromatic hydrocarbon-dicyanobenzene and-n.n-dimethylaniline systems in aqueous micellar solutions

Fluorescence quenching of pyrene and several other aromatic hydrocarbons by dicyanobenzenes as well as N,N-dimethylaniline has been observed in aqueous micellar solutions. The experimental results have been explained by means of equations for fluorescence intensity and decay curve derived on the basis of a simplified model.     

Cetylpyridinium chloride micelles as a selective fluorescence quenching solvent media for discriminating between alternant versus nonalternant polycyclic aromatic hydrocarbons

Fluorescence behavior of 41 polycyclic aromatic hydrocarbons (PAHs) dissolved in aqueous micellar cetyltrimethylammonium chloride (CTAC) solvent media and in five different cetyltrimethylammonium chloride + cetylpyridinium chloride (CPC) surfactant mixtures is reported. Experimental fluorescence measurements reveal that CPC is a selective fluorescence quenching agent for alternant PAHs. The cetylpyridinium ion effectively quenched emission intensities of the 21 alternant PAHs studied. Emission intensities of nonalternant PAHs, with a few noted exceptions, were unaffected by the presence of CPC in the mixed cationic surfactant micelles.     

三维导数荧光光谱总体积积分法同时测定多环芳烃

本文提出了一种运用Monte-Carlo积分求算总荧光强度的三维导数荧光光谱法总体积积分法, 并应用于多环芳烃萘、芘、北的同时测定。结果表明, 三维导数荧光光谱总体积积分法的选择性较三维荧光光谱有进一步的提高, 总体积积分法的灵敏度比常规单点法提高10~20倍。     

抚顺乙烯焦油的精馏分离与气相色谱-质谱联用分析

为避免乙烯焦油作为燃料粗放燃烧造成的芳烃资源浪费与环境污染,我们以抚顺乙烯焦油为原料,常压蒸馏切割<280 ℃馏分,然后采用填充柱进行常压精馏,将<280 ℃馏分切割为12个馏分段(40~150 ℃、150~170 ℃、170~180 ℃、180~190 ℃、190~200 ℃、200~210 ℃、210~220 ℃、220~230 ℃、230~240 ℃、240~250 ℃、250~260 ℃和260~280 ℃),以达到对抚顺乙烯焦油的精馏分离。 以HP-5MS毛细管填充柱为色谱柱,对得到的12个馏分段进行气相色谱-质谱联用定性、定量分析,为乙烯焦油中芳烃的提取和乙烯焦油深加工利用提供具有指导价值的分析数据。 结果显示,抚顺乙烯焦油<280 ℃馏分占焦油总量的52.2%,主要由1~4芳香烃组成。 单环、三环和四环芳烃质量分数较少,单环芳烃主要为苯的衍生物,质量分数为5.8%,3环和4环芳烃占2.998%,主要为苊、芴、蒽、菲、芘等。 抚顺乙烯焦油中质量分数最多的双环芳烃为萘,其次为β-甲基萘、α-甲基萘和1,4-二氢萘,它们在各馏分段的最高分布分别为41.152%、16.729%、12.089%和9.046%。 由此乙烯焦油可作为提取高附加值芳环类精细化工产品的良好原料。     

Determination of Polycyclic Aromatic Hydrocarbons in Camellia Oil by Gel Permeation and High-Performance Liquid Chromatography

A rapid method for the quantification of polycyclic aromatic hydrocarbons in camellia oil is reported. The analytes were extracted from camellia oil using 1:1 (v/v) cyclohexane/ethyl acetate, isolated by gel permeation chromatography, and determined by high-performance liquid chromatography with fluorescence detection. The method features good sensitivity, as the limits of quantification were from 0.33 to 0.67 microgram per kilogram, which are lower than those of regulatory maximum residue limits. Intra- and inter-day precision ranged from 1.19 to 4.52 percent and 1.86 to 3.56 percent, respectively. The recoveries were 79.3–87.9, 85.3–93.4, and 89.6–97.3 percent at fortified levels of 10, 25, and 50 microgram per kilogram, respectively. Moreover, the method is rapid, requiring less than three hours, in comparison to traditional approaches, which require more than twenty-four hours. The developed method was also inexpensive in terms of solvent use and employed to determine polycyclic aromatic hydrocarbons in five camellia oil products. High concentrations of acenaphthene, benz[a]anthracene, benzo[b]fluoranthene, benzo[k]fluoranthene, and benzo[a]pyrene were present in samples produced through extrusion and high temperature pressing. The results suggest that camellia oil processing should be monitored to minimize the presence of polycyclic aromatic hydrocarbons.     

Evaluation of chromatographic and spectroscopic methods for the analysis of petroleum-derived compounds in the environment

Summary Analytical protocols have been adapted for the study of hydrocarbons at the trace level in the environment. Various samples, including sediments and biota, were collected from the Kuwaiti environment, treated according to the protocol and analyzed by chromatographic and spectroscopic methods. The methods used were synchronous scanning fluorescence spectroscopy (SSFS); high-performance liquid chromatography (HPLC) on C18 reversed-phase and NH2 normal-phase columns with UV and fluorescence detectors; gas chromatography on fused-silica capillary columns (GC) with flame ionization detector (FID), mass spectrometer (MS) and flame photometric detector (FPD); and high-resolution molecular spectrofluorimetry in Shpol'skii matrix at 10 K (HRSS). The different methods were found to give complementary information. SSFS was useful for fast evaluation and preliminary assessment of oil pollution during extended programs; it permitted sample selection for deeper analyses but, when applied to biota, needed special care in the clean-up procedure. GC/FID, was used to analyze saturated and ethylenic compounds and was useful for obtaining information on the origin of hydrocarbons but inconvenient for analyzing the aromatic fraction. GC/FPD was difficult to use with sediment samples and yielded little information on biota samples, although it did permit confirmation of high oil contamination in some examples. HPLC on a normal-phase column with UV and fluorescence detectors was useful for the fractionation of samples and for the separation of different families of aromatic compounds according to aromatic carbon number. GC/MS was used to quantify polycyclic aromatic hydrocarbons (PAHs) of less than four cycles but was not sensitive enough for PAHs of higher molecular weight. HRSS, however, was useful for the quantification of heavy PAHs and was also faster, could be automated, and gave accurate results. However, in an oil-pollution study, it must be backed up by the other techniques. In fact, no single analytical technique was found to be sufficient, and only judicious combinations of the tested techniques yielded adequate information on the origin of hydrocarbons in the environment.