Comparative chemical analysis of commercial creosotes and solvent refined coal-II materials by high resolution gas chromatography

The chemical composition of a commercially available creosote was compared to a direct coal liquefaction product, i.e., solvent refined coal-II fuel oil blend (SRC-II FOB) using high resolution gas chromatography (HRGC). In addition, hydrogenated products of these materials were studied. Samples were fractionated by chemical class on neutral alumina. Those fractions previously shown to be the most mutagenic and tumorigenic in laboratory bioassays of coal-derived materials were analyzed and compared by HRGC and gas chromatography/mass spectrometry (GC/MS). Individual components were tentatively identified and quantitated. Although similar chemical components were present in the creosote and SRC-II FOB fractions studied, the creosotes had higher concentrations of heavy molecular weight materials and a lower ratio of alkylated to parent polycyclic aromatic compounds than the coal liquefaction products. The creosote samples also had a significantly higher concentration of components which eluted in the polycyclic aromatic hydrocarbon (PAH) chemical class fraction. Amino-substituted PAH were present in both nonhydrogenated coal liquid and creosote materials. The creosote and SRC-II FOB crudes and nitrogen-containing polycyclic aromatic compound (NPAC) chemical class fractions expressed similar microbial mutagenicity. Based on chemical analysis data, the predicted tumorigenic potency of the creosote in laboratory bioassay systems would be equivalent to or greater than the SRC-II FOB.     

Determination of hydrocarbon types in petroleum and coal-derived products by thin-layer chromatography/densitometry

Different methodologies based on thin-layer chromatography (TLC)/densitometry were used to separate and quantitate hydrocarbon types in middle distillates (gas oil), heavy distillates (lubricant) from petroleum, and coal-derived products. Thus, petroleum products were separated into saturates and aromatics by development, using n-hexane (9 min) followed by dichloromethane (4.5 min), of silica gel plates impregnated with berberine sulfate. Detection of saturates and aromatics was performed by fluorescence scanning using 365 nm as the excitation wavelength. Alternative detection of aromatics can be performed on either silica gel or berberine-impregnated plates by using ultraviolet (UV) densitometry at 250 nm. On the other hand, polar coal-derived products were separated into aromatics, polar compounds, and uneluted components by using silica gel plates and development with toluene (12 min), followed by dichloromethane-methanol (95 + 5, v/v), with detection by UV densitometry at 250 nm. In all cases, external standard calibration was used for quantitation. Results were validated by using standard methods or well-established techniques of the petrochemical industry. The potential usefulness of TLC/densitometry is discussed.     

压力对塔里木原油四组分热解性能的影响

压力对深层油藏原油热化学过程的影响尚存在较大争议,为研究其在油藏原油热解成气过程中的作用机理,我们在450℃、5~40 MPa压力下对塔里木原油四组分(饱和分、芳香分、胶质和沥青质)进行了封闭体系的热解实验,通过气相色谱(GC)和气相色谱/质谱(GC/MS)分别对原油四组分热解反应的气体产物及饱和分热解过程的液态产物进行了分析。结果表明,在450℃、24 h及不同压力下,沥青质热解产气率高于胶质、芳香分和饱和分;四组分的气相热解产物中,C1的产率明显高于C2~C5组分。增大压力抑制沥青质、胶质及芳香分的热解产气过程而促进饱和分的热解产气过程。随压力的增大,饱和分热解的液态产物的主峰组分碳数先减小,再增大。压力低于20 MPa时,饱和分热解过程中以裂解反应为主;高于30 MPa时,增大压力有利于缩合反应。研究结果可为认识深层油藏原油的稳定程度及天然气的成因提供一定的理论参考。     

Identification of some polycyclic nitrogen-containing compounds in coal-derived oil

A systematic method for the identification of aza-arenes in coal-derived oil was developed. The basic nitrogen-containing substances were extracted with 6 M hydrochloric acid and fractionated sequentially by using gel chromatography and thin-layer chromatography (TLC) on an alumina plate. The aza-arenes in these fractions were separated by using glass capillary gas chromatography. Individual compounds in the column effluent were trapped in a system consisting of a valve for flow switching and a trapping tube made from a glass capillary. The fluorescence spectra of nanogram to subnanogram amounts of trapped compounds were measured. Some attempts were made to identify components based on their TLC RF values and their fluorescence spectra, in addition to their mass spectra.     

Characterization of polycyclic aromatic hydrocarbons and hydroaromatics in a distillable coal-derived solvent by chromatographic and corrected fluorescence methods

Polycyclic aromatic hydrocarbons and hydroaromatics were separated from a coal-derived distillate by dry-column chromatography and high-performance liquid chromatography. Individual components in the isolated fractions were characterized by corrected excitation fluorescence spectrometry. With the chromatographic data and the fluorescence data, compound identification was possible in some cases.     

Characterization of Oil by Micro-Solid-Phase Extraction and Gas Chromatography–Mass Spectrometry

Micro-solid-phase extraction is reported for the preparation of Bohai crude oil for the determination of hydrocarbons by gas chromatography-mass spectrometry. The operational parameters were optimized. Micro-solid-phase extraction provided higher quantities of low-molecular weight components than conventional liquid chromatography. The concentrations of high-molecular weight n-alkanes, polycyclic aromatic hydrocarbons, and their alkylated homologs obtained were comparable by micro-solid-phase extraction and liquid chromatography. The diagnostic ratios also indicated that there were no significant differences between these methods. Therefore, micro-solid-phase extraction with gas chromatography–mass spectrometry is recommended for the characterization of spilled oil.     

Analysis of coal tar and petroleum pitches by computerized pattern recognition

Pyrolysis gas chromatography (P/GC) has been successful in differentiating coal tar pitches which are used in the manufacture of high temperature graphite materials [1,2]. In the present study, coal tar and petroleum pitches received from five suppliers were readily differentiated using three distinct methods of polymer analysis: dynamic headspace and pyrolysis gas chromatography mass spectrometry (DH/GC/MS and P/GC/MS, [3]), and pyrolysis mass spectrometry (P/MS, [4,5]). All of these methods are appropriate for the analysis and pattern recognition study of coal and petroleum products; however, methods which incorporate GC usually necessitate long analysis times and are subject to problems associated with gas chromatographic reproducibility (e.g. active sites [6], and nonconstant retention times). As a fingerprint analysis method, P/MS is rapid and ideally suited to computerized pattern recognition study of pitches due to the simple format of P/MS data (computer tabulation of normalized intensities versus masses); whereas, in the present study, the normalized peak area versus retention time date from DH/GC/MS and P/GC/MS analyses were not suitable for direct input to a computerized pattern recognition analysis program, (due to non-constant retention times and improper data format). One limitation is that P/MS does not provide positive identification of thermally evolved products (as can DH/GC/MS and P/GC/MS) due to the complexity of the spectra of a mixture of compounds produced by P/MS. Within the limits of the commercial instrumentation and computer programs used in this study, a combination of all three techniques provided the greatest capability for the differentiation of the five coal tar and petroleum based pitches studied.     

气相色谱/质谱结合化学计量学解析方法用于植物精油成分分析

使用气相色谱/质谱(GC-MS)法对缬草精油和含有缬草精油的混配精油的化学成分进行了分析.采用直观推导式演进特征投影法(HELP)对二维数据中的色谱重叠峰进行了解析,得到两种精油的各个物质的纯色谱和纯质谱,同时利用交互移动窗口因子分析法(AMWFA)直接比较两种精油中的共有组分,提取出共有组分的纯质谱,通过与HELP法解析出的质谱进行比较,发现AMWFA法比HELP法能更快速鉴别出混配精油中的缬草精油.     

Antifungal activity of the essential oil of Illicium verum fruit and its main component trans-anethole

In order to identify natural products for plant disease control, the essential oil of star anise (Illicium verum Hook. f.) fruit was investigated for its antifungal activity on plant pathogenic fungi. The fruit essential oil obtained by hydro-distillation was analyzed for its chemical composition by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). trans-Anethole (89.5%), 2-(1-cyclopentenyl)-furan (0.9%) and cis-anethole (0.7%) were found to be the main components among 22 identified compounds, which accounted for 94.6% of the total oil. The antifungal activity of the oil and its main component trans-anethole against plant pathogenic fungi were determined. Both the essential oil and trans-anethole exhibited strong inhibitory effect against all test fungi indicating that most of the observed antifungal properties was due to the presence of trans-anethole in the oil, which could be developed as natural fungicides for plant disease control in fruit and vegetable preservation.     

Static headspace‐multicapillary column with gas chromatography coupled to ion mobility spectrometry as a simple approach for the discrimination of crude and processed traditional Chinese medicines

The processing procedure can alter the nature and chemical transformation of traditional Chinese medicine to accommodate different clinical dispensing and preparation requirements. In this study, static headspace‐multicapillary column with gas chromatography coupled to ion mobility spectrometry was developed for the rapid and sensitive discrimination of crude and processed traditional Chinese medicine. Using Radix Paeoniae Alba as a traditional Chinese medicine model, the combined power of this approach was illustrated by classifying the crude and processed Radix Paeoniae Alba samples into two main categories. The contents of the main components in Radix Paeoniae Alba varied significantly. The established method could promote the use of ion mobility spectrometry in intrinsic quality control and differentiation of herbal medicines from other processed products or preparations.     

全二维气相色谱-飞行时间质谱联用技术分析重馏分油中芳烃组成

通过对升温速度、二维补偿温度、调制周期等关键实验参数的优化,建立了全二维气相色谱-飞行时间质谱(GC×GC-TOF MS)分析重馏分油中芳烃组分的方法,得到了重馏分油芳烃组分按环数分布的二维点阵图。根据谱库检索、标准化合物对照及文献报道,对重馏分油芳烃组分中菲、甲基菲及芘、苯并蒽等常见多环芳烃(PAH)进行了准确定性,并将该方法应用到重馏分油加氢处理工艺研究中,对菲、芘的加氢处理产物进行了定性分析。该研究为重馏分油芳烃组分的准确定性提供了新的技术手段,为加深对油品加氢规律的认识提供了技术支持。全二维气相色谱与普通一维色谱对比,在重馏分油的芳烃组分分析上体现了极大优势。     

Development of direct microwave desorption/gas chromatography mass spectrometry system for rapid analysis of volatile components in medicinal plants

A new direct microwave desorption–gas chromatography‐mass spectrometry method was developed for the analysis of the essential oils of medicinal plants. A homemade direct microwave desorption system was fabricated and used for the desorption of volatile components of medicinal herbs. The desorbed volatiles are transferred directly into the gas chromatography injector for analysis in a one‐step process. Approximately 0.3 g of the herb was needed for the desorption of samples in 60 s. In this study, more than 53 volatile compounds were identified and quantified for Echinophora platyloba DC as model herb sample. The results were found to be in good agreement with the conventional hydrodistillation extraction data. The described results show that direct microwave desorption is fast, simple, and easy to automate and requires only a small amount of sample. The results indicate that essential oil components valuable for varietal identification and characteristic of each variety analyzed when direct microwave desorption–gas chromatography‐mass spectrometry was used for analysis.     

Application of pyrolysis - GC and pyrolysis - GC-MS to fossil fuel research

Pyrolysis - gas chromatography (py-GC) and pyrolysis-gas chromatography - mass spectrometry (py-GC-MS) are used increasingly in fossil fuel research. These techniques can be employed to determine the source and maturity of organic matter in coals, oil shales and oil source rocks and to identify liquefaction products from coal and oil shales.     

气相色谱/质谱法分析曼陀罗果实挥发油的化学成分

用水蒸汽蒸馏法从曼陀罗果实中提取挥发油,并用气相色谱/质谱(GC/MS)联用技术对其化学成分进行分离和结构鉴定,用峰面积归一化法确定各成分的相对含量。结果确定了68种化合物,占挥发油总量的82.83%,其主要成分为6-戊基-5,6-二氢化吡喃-2-酮(9.13%)、3,7,11,15-四甲基-2-十六碳烯-1-醇(6.71%)、二苯酮(6.16%)和1-己醇(6.10%)等。     

湘西金银花挥发油化学成分研究

采用ＧＣ／ＭＳ／ＤＳ联用仪对湘西金角花挥发油中的化学成分进行了研究。并鉴定出４０种组分。其主要成分为：芳樟醇、环氧芳樟醇、α－萜品醇、顺－３－已 烯醇、顺芷酸－３、己烯酯、香叶醇、氧化芳樟醇、法尼醇、顺－苯酮、法尼烯、大根香叶烯、橙花醇等。其中芳樟醇含量最高,约占精油总量的２０％。     

Chromatographic chemical characterization of solvent refined coal I and II liquids for toxicological testing

Summary High resolution gas chromatography and gas chromatography/mass spectrometry were employed to determine the components in samples of solvent refined coal (SRC) II naphtha, middle distillate, heavy distillate, and fuel oil blend and SRC-I light oil, wash solvent, and process solvent in concentrations higher than approximately 0.5%. Quantitation was based on the addition of n-alkane internal standards and peak area response of a flame ionization detector with the use of fused silica and glass capillary columns coated with SE-52 and SF-96. The major differences in the SRC-I and II materials were the molecular weight ranges and sizes of the chemical components found in the products, an effect of the differences in the nominal boiling ranges of the materials. Alkanes, alkenes, hydroxylated aromatics, hydrogenated and polycyclic aromatic hydrocarbon ring systems, and alkylated derivatives of the above were found in greatest concentration in the unfractionated materials. Sulfur and nitrogen heteroatomic species were in greates concentration in the higher nominal boiling range materials. A major purpose of these investigations was to develop a method to obtain data on the composition of these complex sample matrices for use in designing studies for toxicological evaluation of these materials.     

多花蔷薇花净油化学成分研究

多花蔷薇(Rose multiflora. cathayensis)又名红刺玫、刺花,系多年生落叶灌木,野生于甘肃省陇南山区,生长在海拔500～1900 m的山峰、河岸或山坡缘及灌木丛林中,花的资源丰富,是甘肃省目前需开发的野生芳香植物之一,多花蔷薇花为粉红色,花期为5月中旬至5月底,花中含芳香油,可用作化妆、皂用香精等,有关多花蔷薇花的化学成分,未见文献报道,我们将多花蔷薇花的石油醚浸膏用乙醇在0℃脱蜡3次得净油,再经硅胶柱层析分离得纯     

A simple and controlled oxidative decontamination of sulfur mustard and its simulants using ozone gas

A simple and efficient oxidative decontamination method was developed for sulfur mustard (HD), a potential chemical warfare agent. The method involves treatment of chemical warfare agent HD and its simulants, i.e., dimethyl sulfide, diethyl sulfide, and 2-chloroethyl ethyl sulfide with ozone gas at ambient conditions in acetonitrile solvent. Ozone gas readily oxidizes sulfur mustard in a controlled manner to give its corresponding nontoxic sulfoxide. This transformation is selective and takes place even at subzero temperatures. The oxidation products of HD and its simulants were monitored and quantified by gas chromatography and gas chromatography–mass spectrometry.     

Application of complementary mass spectrometric techniques to the identification of ketoprofen phototransformation products

Ketoprofen (KP) is a nonsteroidal anti-inflammatory drug, which during UV irradiation rapidly transforms into benzophenone derivatives. Such transformation products may occur after topical application of KP, which is then exposed to sunlight resulting in a photo-allergic reaction. These reactions are mediated by the benzophenone moiety independently of the amount of allergen. The same reactions will also occur during wastewater or drinking water treatment albeit their effect in the aqueous environment is yet to be ascertained. In addition, only a few such transformation products have been recognised. To enable the detection and structural elucidation of the widest range of KP transformation products, this study applies complementary chromatographic and mass spectrometric techniques including gas chromatography coupled to single quadrupole or ion trap mass spectrometry and liquid chromatography hyphenated with quadrupole-time-of-flight mass spectrometry. Based on structural information gained in tandem and multiple MS experiments, and on highly accurate molecular mass measurements, chemical structures of 22 transformation products are proposed and used to construct an overall breakdown pathway. Among the identified transformation products all but two compounds retained the benzophenone moiety--a result, which raises important issues concerning the possible toxic synergistic effects of KP and its transformation products. These findings trigger further research into water treatment technologies that would limit their entrance into environmental or drinking waters.     

松潘乌头和展毛多根乌头挥发油的GC／MS分析

松潘乌头(Aconitum sungpanense Hand.-Mazz.)为毛茛科乌头属植物,根有剧毒,供药用,可治疗跌打损伤、风湿性关节痛等症.主产于甘肃南部、四川北部、青海东部等地.我们曾对其进行了二萜生物碱的分离鉴定.展毛多根乌头(A.Karakolicum var.patentipilumW.T.Wang)是新疆民间常用草药之一,民间称为草乌,主治神经痛、牙痛等症.我们曾对