Atwah Ibrahim, Alsaif Maram, Usman Muhammad, Abualreesh Mohammed
EXPEC Advanced Research Center, Saudi Aramco, P.O. Box 5000, Dhahran 31311, Saudi Arabia.
Physical Science and Engineering Division, King Abdullah University of Science and Technology (KAUST), P.O. Box 4700, Thuwal 23955-6900, Saudi Arabia.
ACS Omega. 2025 Jun 23;10(26):27806-27818. doi: 10.1021/acsomega.5c00439. eCollection 2025 Jul 8.
Saturates, aromatics, resins, and asphaltenes (SARA) analysis is essential for petroleum characterization, providing critical insights into crude oil properties that impact exploration, production, refining, and transport. However, many current methods have issues such as long runtime, system complexity, and reproducibility challenges. To address these issues, this study introduces μSARA-HPLC, an optimized, automated SARA analysis system using high-performance liquid chromatography (HPLC) with fraction collection. The system features three columns: a Polaris Si-SA MetaGuard column for asphaltene precipitation, a ZORBAX SB-CN column for resin separation, and a ZORBAX RX-SIL column for aromatics. The solvent gradients are carefully controlled, with mid-run flow reversal to ensure comprehensive separation. Elution windows are set using model compounds and verified via gas chromatography-mass spectrometry (GC-MS) for saturates and aromatics and Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS) for resins and asphaltenes. The system runs at 1.5 mL/min with -pentane, dichloromethane, methanol, and isopropanol, with each run completed in 35 min, reducing the analysis time significantly compared with existing methods. Sample use is minimized and column life is extended by using injection volumes of 1.5-3 μL from 1:100 dilutions of oil (10 mg of oil in 100 μL of DCM). Dual detection using an evaporative light scattering detector (ELSD) and a diode array detector (DAD) provides exceptional sensitivity for all fractions, achieving detection limits as low as 0.05% by weight and an average recovery rate of 99.52%. Reproducibility was validated across crude oils and bitumen with varying API gravities, including extra-heavy and ultralight samples, using the NSO-1 reference oil over four months, which resulted in less than 1% deviation. This novel system provides a fast, reliable, and scalable approach to SARA analysis, advancing standardization in research and industry.
饱和烃、芳烃、树脂和沥青质（SARA）分析对于石油表征至关重要，它能为影响勘探、生产、精炼和运输的原油性质提供关键见解。然而，当前许多方法存在运行时间长、系统复杂以及重现性挑战等问题。为解决这些问题，本研究引入了μSARA-HPLC，这是一种经过优化的自动化SARA分析系统，采用高效液相色谱（HPLC）并带有馏分收集功能。该系统有三根色谱柱：用于沥青质沉淀的Polaris Si-SA MetaGuard柱、用于树脂分离的ZORBAX SB-CN柱以及用于芳烃分离的ZORBAX RX-SIL柱。溶剂梯度受到精心控制，运行过程中进行流动反转以确保全面分离。使用模型化合物设置洗脱窗口，并通过气相色谱-质谱联用（GC-MS）对饱和烃和芳烃进行验证，通过傅里叶变换离子回旋共振质谱（FT-ICR-MS）对树脂和沥青质进行验证。该系统以1.5 mL/分钟的流速运行，使用正戊烷、二氯甲烷、甲醇和异丙醇，每次运行在35分钟内完成，与现有方法相比显著缩短了分析时间。通过使用1:100稀释油样（10毫克油溶于100微升二氯甲烷）的1.5 - 3微升进样体积，将样品用量降至最低并延长了色谱柱寿命。使用蒸发光散射检测器（ELSD）和二极管阵列检测器（DAD）进行双重检测，对所有馏分都具有出色的灵敏度，检测限低至0.05%（重量），平均回收率为99.52%。在四个月的时间里，使用NSO-1参考油对不同API重度的原油和沥青进行验证，包括超重和超轻样品，重现性偏差小于1%。这种新型系统为SARA分析提供了一种快速、可靠且可扩展的方法，推动了研究和行业的标准化进程。
