Mdluli Njabulo S, Knottenbelt Cyril D, Nomngongo Philiswa N, Mketo Nomvano
Department of Chemistry, College of Science and Engineering and Technology, Florida Science Campus, University of South Africa, Roodepoort, Johannesburg, 1710, South Africa.
PetroSA, Private Bag X14, Mossel Bay, 6520, South Africa.
Sci Rep. 2024 Jan 29;14(1):2362. doi: 10.1038/s41598-024-52898-4.
This work describes a greener and cost-effective microwave-assisted hydrogen peroxide digestion (MA-HPD) with the addition of 1 mL of HNO (70% v/v) to enhance extraction of selected metals (Al, Ba, Cd, Co, Cr, Cu, Mg, Na, Ni, Pb, Sb, Ti and V) in crude-oil, diesel, gasoline and kerosene samples prior to inductively coupled plasma-optical emission spectroscopic (ICP-OES) analysis. The most influential parameters of the MA-HPD method were investigated by using multivariate optimization tools (two-level full factorial and central composite designs) and fuel oil certified reference material (NIST1634c). The optimum conditions were observed to be 245 ℃ microwave temperature, 25 min digestion time, 0.1 g sample mass and 5 M HO were the optimum digestion conditions with accepted accuracy (104.8-117.7%) and precision (≤ 4.1%). In overall, the metals that reported high concentrations in the crude oil, diesel, gasoline, and kerosene samples were Na (51.94-58.86 mg/kg) and Mg (36.08-47.4 mg/kg), while Cu was the lowest (0.55-2.89 mg/kg). When comparing the obtained concentration levels with other literature reports, a conclusion can be drawn that South Africa is importing oils of reasonable quality.
这项工作描述了一种更环保且经济高效的微波辅助过氧化氢消解（MA - HPD）方法，即在电感耦合等离子体发射光谱（ICP - OES）分析之前，向原油、柴油、汽油和煤油样品中加入1 mL硝酸（70% v/v）以增强所选金属（铝、钡、镉、钴、铬、铜、镁、钠、镍、铅、锑、钛和钒）的萃取。通过使用多变量优化工具（二级全因子设计和中心复合设计）以及燃料油标准参考物质（NIST1634c），对MA - HPD方法最具影响力的参数进行了研究。观察到最佳条件为微波温度245℃、消解时间25分钟、样品质量0.1 g以及5 M过氧化氢，这些是具有可接受准确度（104.8 - 117.7%）和精密度（≤4.1%）的最佳消解条件。总体而言，在原油、柴油、汽油和煤油样品中报告浓度较高的金属是钠（51.94 - 58.86 mg/kg）和镁（36.08 - 47.4 mg/kg），而铜的含量最低（0.55 - 2.89 mg/kg）。将获得的浓度水平与其他文献报告进行比较时，可以得出南非进口的油品质量合理的结论。
