气相色谱法测定催化柴油中硫化物类型分布及数据对比

采用气相色谱-氢火焰离子化检测器-硫化学发光检测器（GC—FID—SCD）联用技术,建立了催化柴油中各种硫化物类型分布的分析方法。考察了色谱条件对催化柴油中各种硫化物分离的影响,定性了某催化柴油中的120多个硫化物,该方法还可以同时提供催化柴油中正构烷烃含量的分布信息。硫化物中的硫在1．5—700mg／L时其峰面积与质量浓度呈较好的线性关系,相关系数达0．9999,响应与硫化物的类型无关。催化柴油中苯并噻吩、4-甲基苯并噻吩、二苯并噻吩、4-甲基二苯并噻吩和4,6-二甲基二苯并噻吩等主要硫化物浓度测定的相对标准偏差（RSD）均小于5．0％。当信噪比（S／N）为3时,测得苯并噻吩硫的检出限为0．1mg／L。将该方法用于不同来源柴油中各种硫化物类型分布的研究,并与气相色谱一原子发射光谱检测器（GC—AED）测硫的数据进行了对比,两种检测器的定量结果大多数具有较好的相关性,相关系数大于0．95。     

全二维气相色谱分析直馏柴油中含硫化合物

采用全二维气相色谱-硫化学发光检测器,以直馏柴油为研究对象,考察了一维色谱柱初始温度、升温速率及两维柱温温差等条件对含硫化合物分离的影响,建立了直馏柴油中含硫化合物的分析方法。本方法对基质复杂的直馏柴油中含硫化合物的分离,并定性分析或归类了直馏柴油中的主要含硫化合物。以苯并噻吩为测试样,以峰面积对浓度作图,硫的浓度在1～100mg/kg范围内,峰面积与硫的浓度呈线性关系,相关系数大于0.999。与传统一维气相色谱相比,全二维气相色谱技术除可检测到苯并噻吩类、二苯并噻吩类等含硫化合物外,还可检测到直馏柴油中的硫醚类化合物;苯并噻吩类和二苯并噻吩类化合物也可得到较好分离。     

催化柴油中硫化物的气相-原子发射光谱分析方法及应用

 建立了催化柴油馏分中各种硫化物类型分布的气相 原子发射光谱分析方法,考察了条件对各种硫化物分离的影响,定性(或归类)了催化柴油中的130多个硫化物,计算了程序升温条件下各种硫化物的保留指数,为不同实验室的定性比较和方法的转让提供了依据。硫化物中的硫在2mg/L～1000mg/L时其质量浓度与峰面积呈较好的线性关系,相关系数达0 997。几种硫化物(苯并噻吩、4 甲基苯并噻吩、二苯并噻吩、4 甲基二苯并噻吩、4,6 二甲基二苯并噻吩)6次测定所得峰面积的相对标准偏差均小于5 0%。当信噪比(S/N)为3时,测得苯并噻吩硫的检出限为0 1mg/L。     

哈萨克斯坦及俄罗斯渣油馏分中的硫化物裂解色谱分析

采用裂解气相色谱接脉冲火焰光度检测器（PY-GC-PFPD）,研究了哈萨克斯坦原油及俄罗斯减压原油渣油及其馏分的裂解硫化物的组成分布。依据渣油高温裂解硫化物的主要类型：H2S、噻吩类、苯并噻吩类及二苯并噻吩类,选择噻吩、苯并噻吩（BT）和二苯并噻吩（DBT）模型化合物,考察裂解温度400℃-1000℃及时间5 s-10 s的反应产物及转化率,以证明渣油裂解硫化物基本可反映其在渣油中的结构。采用超临界流体萃取分馏,将俄罗斯和哈萨克斯坦渣油分别分割成18和19个窄馏分,在裂解温度1000℃及10 s条件下,获得了两种渣油及其馏分中H2S、噻吩、BT和DBT的含量分布,推断了渣油中硫化物噻吩类和硫醚类分布规律。     

GC／MS分析煤抽出物中的含硫多环芳香化合物

煤的索氏抽出物中的含硫多环芳香化合物（ＰＡＳＨ）由硅胶柱色谱与配体交换薄层色谱（ＰｄＣｌ＿２／ＳｉＯ＿２）两步分离，用毛细管气相色谱（ＦＩＤ与ＦＰＤ）和色质联用仪分析其组成、结构。通过与文献的色谱保留指数相比较、质谱数据验证，鉴定出贵定煤含硫芳香化合物以三、四环结构为主，主要是二苯并噻吩及其Ｃ＿１～Ｃ＿３烷基取代物、苯并萘并噻吩及其烷基取代物，其它稠环含硫芳香化合物较少。     

柴油馏分中含硫化合物组成与分布特征

采用毛细管气相色谱/脉冲火焰光度检测器(GC/PFPD,Gas Chromatograph/ Pulsed Flame Photometric Detector)对新疆独山子石化公司炼油厂的五种柴油馏分中的硫化物进行了分析。结果表明,常一线馏分中所含的硫化物主要是C0~4苯并噻吩;常二线馏分中除含有C_1~4苯并噻吩外还含有大量的C_0~3二苯并噻吩及部分未知硫化物;焦化柴油中硫化物组成最为复杂,包含中间馏分油中所有常见的硫化物类型;而催化裂化柴油和加氢柴油中硫化物类型主要为烷基苯并噻吩和烷基二苯并噻吩,其中加氢柴油中的硫化物相对丰度比催化裂化柴油低的多。     

浮选药剂中典型污染物PASH 的GC-MS检出

有机含硫芳香化合物(PASH)性质稳定,不宜降解,毒性极强,且比多环芳烃和含氮杂环化合物更具致癌性[1,2].PASH包括含芳基的硫醇、硫醚、二硫代物噻吩及其同系物,还有苯并噻吩类、二苯并噻吩类.     

气相色谱-原子发射光谱联用技术测定柴油中硫化物

采用气相色谱－原子发射光谱（GC－AED）联用技术对柴油中硫化物进行了定性定量研究，考察了柴油加氢脱硫处理前后硫化物的变化及不同柴油原料硫化物的分布情况。结果表明，1＃柴油可定性出33类硫化物，经加氢脱硫处理后，1－1＃和1－2＃样品硫含量可由1497mg/L分别降到165.1mg/L和90.4mg/L，平均脱除率为89.0%和94.0%。其中噻吩或苯并噻吩的脱除率为100％；C1二苯并噻吩的肿除率为90.0%和96.2%;C2二苯并噻吩的脱除率为80.6%和91.7%；C3二苯并噻吩的脱除率为72.6%和84.4%；C4二苯并噻吩的脱除率为79.0%和90.3%;C5或C6二苯并噻吩的脱除率为58.4%和68.4%；未知硫化物脱除率95.7%和97.9%。噻吩类脱除率视取代基的大小、个数和取代位置的不同脱除率不同；不同原料 总硫和各种硫化物含量差别很大，应根据其硫化物的分布特点，有针对性地研制开发加氢脱硫的催化剂及选择合适的加工工艺。     

NiY分子筛选择性吸附脱硫性能及作用机理

用液相离子交换法制备了NiY分子筛,并用XRD、TEM、ICP、N2吸附和吡啶吸附原位红外技术等表征手段对其进行了表征. 利用固定床、气相色谱-硫发光检测器（GC-SCD）及傅里叶红外光谱（FT-IR）等方法系统研究了NiY分子筛对噻吩、2-甲基噻吩、3-甲基噻吩、四氢噻吩、苯并噻吩、二苯并噻吩、4-甲基二苯并噻吩、4,6-二甲基二苯并噻吩8种有机硫化物的选择性吸附脱硫性能和吸附机理. 结果表明,NiY分子筛对硫化物的穿透吸附硫容量顺序为四氢噻吩﹥苯并噻吩≈二苯并噻吩≈4,6-二甲基二苯并噻吩﹥4-甲基二苯并噻吩﹥2-甲基噻吩≈3-甲基噻吩﹥噻吩,说明有机硫化物的空间位阻效应不是其在NiY分子筛上吸附的决定因素. 红外结果表明,不同硫化物与NiY分子筛的作用机理并不相同,但主要以硫原子与金属离子配位作用（S-M作用）为主. 噻吩及其烷基取代物在NiY吸附剂上表面酸性作用下发生催化反应,噻吩环的共轭体系遭到破坏形成硫化物大分子或聚合物,导致分子筛孔道的堵塞,严重影响吸附剂的吸附脱硫能力. NiY的选择性吸附脱硫性能是硫化物与吸附中心的作用模式及吸附剂表面酸性综合作用的结果.     

加拿大合成原油减压馏分油及其催化裂化液体产物中含硫化合物分析

应用GC PFPD和GC MS技术对加拿大油砂合成原油（Synthetic Crude Oil，简称SCO）减压馏分油（350 ℃~500 ℃）中的含硫化合物进行定性定量分析。结果表明，所含硫化物主要是C3~7二苯并噻吩，而催化裂化反应后则以短侧链二苯并噻吩为主，还含少量烷基苯并噻吩和烷基噻吩，三者的质量分数分别为82.04%、13.42%和0.56%，均属于难以加氢脱除的含硫化合物。SCO减压馏分油和大港减压馏分油按不同比例混合后进行催化裂化反应，随着加拿大合成原油减压馏分油搀兑比增加，所得液相产物中烷基噻吩和烷基苯并噻吩质量分数逐渐降低，烷基二苯并噻吩相对质量分数增加，4-MDBT是丰度最高的含硫化合物，显示加氢油的特征。随掺兑比的提高，液相产物中总硫质量分数和柴油馏分中硫质量分数逐渐增高，而汽油馏分中硫质量分数逐渐降低。     

Sulfur speciation of Kuwaiti crude oils fractions using two-dimensional gas chromatography

The main objective of this study is to develop a methodology for sulfur compounds speciation using two-dimensional gas chromatography coupled with a flame ionization detector and sulfur chemiluminescence detectors. The methodology enhances the ability to detect and quantify the refractory sulfur in petroleum distillates, and it was utilized to screen the molecular differences between distillates of two Kuwaiti heavy crude oils from different reservoirs but with similar physical properties. Despite the similarity in the physical properties, the detailed comparative analysis indicated significant differences in molecular composition, which suggests substantial differences in crude oil processability based on the reactivity of the detected compounds. The distillates that have been considered in this study include heavy naphtha, kerosene, and gas oil. The compositional differences between the distillates were observed using the two-dimensional gas chromatography system with an in-house developed method. This method groups the sulfur compounds into thiols, benzothiophenes (BTs), and dibenzothiophene (DBTs), and it can handle any atmospheric distillate up 365 °C. Furthermore, the method includes the possibility of identifying and quantifying a total number of 44 sulfur species, which covers the previously mentioned sulfur groups.     

Determination of polycyclic aromatic sulfur heterocycles in diesel particulate matter and diesel fuel by gas chromatography with atomic emission detection

The sulfur content of diesel fuel is of environmental concern because sulfur can facilitate the formation of diesel particulate matter (DPM) and sulfur dioxide (SO2) in the exhaust can poison catalytic converters. The US Environmental Protection Agency (EPA) has established more stringent regulations to reduce the sulfur content of diesel fuels in the near future. In this study, various types of organosulfur compounds in DPM extracts and the corresponding fuels have been determined by gas chromatography with atomic emission detection. The diesel fuels used have sulfur contents of 2284 and 433 ppm, respectively, and are labeled as high-sulfur and low-sulfur diesel fuels. The compounds identified are mainly polycyclic aromatic sulfur heterocycles (PASHs). In the fuels tested, trimethylbenzothiophenes (TMBTs), dibenzothiophenes (DBTs), and 4-methyldibenzothiophene (4-MDBT) were the most abundant sulfur compounds, while larger PASH compounds were more abundant in DPM extracts. The high-sulfur diesel fuel contained a larger proportion of PASHs with one or two rings (lighter PASHs). In DPM, the concentrations of total organic sulfur and individual PASHs are higher for the high-sulfur diesel fuel, and the relative percentage of one or two-ring PASHs is higher as well. The influence of engine load on the DPM composition was also examined. With increasing load, the PASH concentration in DPM decreased for lighter PASHs, increased for heavier PASHs, and had a bell-shaped distribution for PASHs in between.     

Evaluation of comprehensive two-dimensional gas chromatography with flame photometric detection: Potential application for sulfur speciation in shale oil

Flame photometric detection in the sulfur channel has been evaluated for sulfur speciation and quantification in comprehensive two-dimensional gas chromatography [GC × GC-FPD(S)] for S-compound speciation in shale extracts. Signal non-linearity and potential quenching effects were reportedly major limitations of this detector for analysis of sulfur in complex matrices. However, reliable linear relationships with correlation coefficient >0.99 can be obtained if the sum of the square root of each modulation slice in GC × GC is plotted vs. sulfur concentration. Furthermore, the quenching effects are reduced due to essentially complete separation of S-containing components from the hydrocarbon matrix. An increase of S/N of up to 150 times has been recorded for benzothiophene and dibenzothiophene in GC × GC-FPD when compared to GC-FPD due to the modulation process. As a consequence, 10 times lower detection limits were observed in the former mode. The applicability of the method was demonstrated using shale oil sample extracts. Three sulfur classes were completely separated and the target class (thiophenes) was successfully quantified after the rest of the sample was diverted to the second detector by using a heart-cut strategy. Based on the proposed method, 70% of the sulfur in the shale oil was assigned to the thiophenes, 24% to benzothiophenes, and 5% to dibenzothiophene compounds.     

Analysis of sulfur-containing compounds in crude oils by comprehensive two-dimensional gas chromatography with sulfur chemiluminescence detection

This paper reports an analytical method for separating, identifying, and quantifying sulfur-containing compounds in crude oil fraction (IBP-360 degrees C) samples based on comprehensive two-dimensional gas chromatography coupled with a sulfur chemiluminescence detector. Various sulfur-containing compounds and their groups were analyzed with one direct injection. 3620 peaks were detected including 1722 thiols/thioethers/ disulfides/1-ring thiophenes, 953 benzothiophenes, 704 dibenzothiophenes, and 241 benzonaphthothiophenes. The target sulfur compounds and their groups were identified based on the group separation feature and structured retention of comprehensive two-dimensional gas chromatography as well as standard substances. The quantitative analysis of major sulfur-containing compounds and total sulfur was based on the linear response of the sulfur chemiluminescence detector using the internal standard method. The sulfur contents of target sulfur compounds and their groups in 4 crude oil fractions were also determined. The recoveries for standard sulfur-containing compounds were in the range of 90-102%. The quantitative result of total sulfur in the Oman crude oil fraction sample was compared with those from ASTM D 4294 standard method (total S by X-ray fluorescence spectrometry), the relative deviation (RD%) was 4.2% and the precision of the method satisfactory.     

全二维气相色谱/飞行时间质谱用于柴油组成的研究

将全二维气相色谱法(GC×GC)用于柴油馏分的组成分布研究,建立了两种GC×GC方法,一种用于柴油组成的详细表征,另一种用于柴油族组成的快速分离和定量,两种方法均不需要样品预处理。用前一种方法对柴油馏分中的烃类化合物、主要的含硫化合物与含氮化合物组成进行了研究;对催化裂解柴油中的27种含氮化合物和42种含硫化合物进行了定性;用后一种方法在70 min内即可完成柴油馏分族组成的定量分析,应用所建立的方法测定了4个不同来源的柴油馏分中非芳烃、一环芳烃、二环芳烃、三环芳烃的含量,定量结果与ASTM D2425法     

Fragmentation pathways of some benzothiophene radical cations formed by atmospheric pressure chemical ionisation

Polycyclic aromatic sulfur‐containing compounds (PASHs) are commonly found in fossil fuels and are of considerable importance in environmental studies. This work presents detailed studies on the fragmentation patterns of radical cations formed from four representative PASHs, benzo[b]thiophene, dibenzothiophene, 4‐methyldibenzothiophene and 4,6‐dimethyldibenzothiophene, using tandem atmospheric pressure chemical ionization mass spectrometry (APCI‐MS/MS). Understanding these fragmentation patterns can be a useful aid in the analysis of PASHs employing APCI or electron ionization (EI‐MS/MS), either alone or in conjunction with liquid or gas chromatography. Copyright © 2009 John Wiley & Sons, Ltd.     

Ligand exchange chromatography: a vital dimension for the reliable characterization of heterocycles in crude oils and refined products

In the present study, we established a statistical distribution pattern of indigenous sulfur, nitrogen, and oxygen species in Arabian Heavy crude oil and its distilled fractions: naphtha, gas oil, and vacuum gas oil (VGO) using chemical derivatization with methyl iodide and subsequent characterization by positive electrospray Fourier transform mass spectrometry. It was observed that sulfur species for naphtha and gas oil were accumulated at lower double bond equivalent values and at lower carbon numbers compared to VGO, whereas crude oil encompassed a complete range of the sulfur species detected in all distilled fractions. Moreover, the use of alumina column chromatography and ligand exchange chromatography (LEC) on a palladium-bonded silica stationary phase revealed additional structural features of sulfur heterocycles in terms of condensed and non-condensed thiophenes. During LEC separation, in addition to sulfur heterocycles, interesting results were obtained for oxygen-containing compounds. Ortho-substituted alkyl phenols were separated from meta- and para-substituted alkyl phenols on a palladium-bonded silica stationary phase.