Gallacher Christopher, Thomas Russell, Lord Richard, Kalin Robert M, Taylor Chris
Department of Civil and Environmental Engineering, University of Strathclyde, 75 Montrose St., Glasgow, G1 1XJ, UK.
WSP/Parsons Brinckerhoff, Kings Orchard, 1 Queen St, Bristol, BS2 0HQ, UK.
Rapid Commun Mass Spectrom. 2017 Aug 15;31(15):1250-1260. doi: 10.1002/rcm.7904.
Coal tars are a mixture of organic and inorganic compounds that were by-products from the manufactured gas and coke making industries. The tar compositions varied depending on many factors such as the temperature of production and the type of retort used. For this reason a comprehensive database of the compounds found in different tar types is of value to understand both how their compositions differ and what potential chemical hazards are present. This study focuses on the heterocyclic and hydroxylated compounds present in a database produced from 16 different tars from five different production processes.
Samples of coal tar were extracted using accelerated solvent extraction (ASE) and derivatized post-extraction using N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) with 1% trimethylchlorosilane (TMCS). The derivatized samples were analysed using two-dimensional gas chromatography combined with time-of-flight mass spectrometry (GCxGC/TOFMS).
A total of 865 heterocyclic compounds and 359 hydroxylated polycyclic aromatic hydrocarbons (PAHs) were detected in 16 tar samples produced by five different processes. The contents of both heterocyclic and hydroxylated PAHs varied greatly with the production process used, with the heterocyclic compounds giving information about the feedstock used. Of the 359 hydroxylated PAHs detected the majority would not have been be detected without the use of derivatization.
Coal tars produced using different production processes and feedstocks yielded tars with significantly different heterocyclic and hydroxylated contents. The concentrations of the individual heterocyclic compounds varied greatly even within the different production processes and provided information about the feedstock used to produce the tars. The hydroxylated PAH content of the samples provided important analytical information that would otherwise not have been obtained without the use of derivatization and GCxGC/TOFMS.
煤焦油是有机和无机化合物的混合物，是煤气制造和炼焦行业的副产品。焦油成分因许多因素而异，如生产温度和所用蒸馏器的类型。因此，一个包含不同焦油类型中发现的化合物的综合数据库对于理解它们的成分差异以及存在哪些潜在化学危害具有重要价值。本研究聚焦于从五种不同生产工艺的16种不同焦油生成的数据库中存在的杂环化合物和羟基化化合物。
使用加速溶剂萃取（ASE）提取煤焦油样品，并在萃取后使用含1%三甲基氯硅烷（TMCS）的N,O-双（三甲基硅基）三氟乙酰胺（BSTFA）进行衍生化。使用二维气相色谱结合飞行时间质谱（GCxGC/TOFMS）分析衍生化后的样品。
在由五种不同工艺生产的16个焦油样品中，共检测到865种杂环化合物和359种羟基化多环芳烃（PAHs）。杂环化合物和羟基化PAHs的含量均因所用生产工艺的不同而有很大差异，杂环化合物能提供有关所用原料的信息。在检测到的359种羟基化PAHs中，大多数若不使用衍生化方法是无法检测到的。
使用不同生产工艺和原料生产的煤焦油，其杂环和羟基化含量存在显著差异。即使在不同生产工艺中，各个杂环化合物的浓度也有很大差异，并能提供有关生产焦油所用原料的信息。样品中羟基化PAH的含量提供了重要的分析信息，否则若不使用衍生化方法和GCxGC/TOFMS是无法获得这些信息的。
