Department of Chemistry, University of Alberta, Edmonton, AB T6G 2G2, Canada.
J Chromatogr A. 2012 Aug 24;1252:171-6. doi: 10.1016/j.chroma.2012.06.070. Epub 2012 Jun 27.
Alkyl phosphate based gellants used as viscosity builders for fracturing fluids used in the process of hydraulic fracturing have been implicated in numerous refinery-fouling incidents in North America. In response, industry developed an inductively coupled plasma optical emission spectroscopy (ICP-OES) based method for the analysis of total volatile phosphorus in distillate fractions of crude oil; however, this method is plagued by poor precision and a high limit of detection (0.5±1μg phosphorus mL(-1)). Furthermore this method cannot provide speciation information, which is critical for developing an understanding of the challenge of alkyl phosphates at a molecular level. An approach using comprehensive two-dimensional gas chromatography with nitrogen phosphorus detection (GC×GC-NPD) and post-column Deans switching is presented. This method provides qualitative and quantitative profiles of alkyl phosphates in industrial petroleum samples with increased precision and at levels comparable to or below those achievable by ICP-OES. A recovery study in a fracturing fluid sample and a profiling study of alkyl phosphates in four recovered fracturing fluid/crude oil mixtures (flowback) are also presented.
基于烷基磷酸酯的凝胶剂被用作水力压裂过程中压裂液的增粘剂，已被牵涉到北美的许多炼油厂污染事件中。作为回应，工业界开发了一种基于电感耦合等离子体光学发射光谱（ICP-OES）的方法，用于分析原油馏分中的总挥发性磷; 然而，该方法存在精度差和检测限高（0.5±1μg 磷 mL(-1))的问题。此外，该方法不能提供形态信息，这对于在分子水平上理解烷基磷酸酯的挑战至关重要。本文提出了一种使用带有氮磷检测的全面二维气相色谱法（GC×GC-NPD）和柱后切换的方法。该方法能够对工业石油样品中的烷基磷酸酯进行定性和定量分析，其精度提高，且在水平上可与 ICP-OES 相媲美或低于 ICP-OES。还进行了压裂液样品的回收研究和四种回收的压裂液/原油混合物（回注）中烷基磷酸酯的剖析研究。
