Department of Food Chemistry and Analytical Chemistry (170a), Institute of Food Chemistry, University of Hohenheim, Garbenstrasse 28, Stuttgart 70599, Germany.
Department of Food Chemistry and Analytical Chemistry (170a), Institute of Food Chemistry, University of Hohenheim, Garbenstrasse 28, Stuttgart 70599, Germany.
J Chromatogr A. 2022 Jan 11;1662:462732. doi: 10.1016/j.chroma.2021.462732. Epub 2021 Dec 4.
The analysis of mineral oil hydrocarbons in vegetable oils is challenging especially regarding the analysis of mineral oil aromatic hydrocarbons (MOAH) since native terpenes like squalene or β-carotene are usually extracted along with the MOAH fraction and interfere their detection. When applying a recently developed screening method for the analysis of mineral oil saturated hydrocarbons (MOSH) and MOAH in paper and cardboard by planar solid phase extraction (pSPE) to vegetable oils, native terpenes expectably interfered with MOAH analysis. Thus, an adaption of pSPE employing silver ions, named silver ion-planar solid phase extraction (Ag-pSPE), was developed in this study. Impregnation of thin-layers with silver nitrate (AgNO) was found to be very successful in retaining squalene and β-carotene. MOAH analysis of vegetable oils after saponification showed good repeatability (relative standard deviation (%RSD) <10%) and recoveries of 73.4-112.4% at a spiking level of 4.5 mg/kg (n = 4). For MOSH analysis, a simple solid phase extraction (SPE) clean-up with aluminum oxide removed native n-alkanes prior to Ag-pSPE. Recoveries for MOSH were 55.3-84.5% with %RSD <11% at a spiking level of 45.5 mg/kg (n = 4). Limits of decision and quantitation were at 7.2 and 22.2 ng/zone for MOSH and 1.1 and 3.4 ng/zone for MOAH, respectively, which corresponded to the recently introduced pSPE method, thus showing that analytes were not affected by the impregnation of HPTLC plates with AgNO. The method comparison with LC-GC showed similar results for MOSH, while the amounts for MOAH determined by Ag-pSPE were higher.
植物油中矿物油烃的分析具有挑战性，尤其是在分析矿物油芳烃（MOAH）时，因为天然萜烯，如角鲨烯或β-胡萝卜素，通常与 MOAH 馏分一起提取，并干扰其检测。当应用最近开发的平面固相萃取（pSPE）分析纸和纸板中矿物油饱和烃（MOSH）和 MOAH 的筛选方法时，天然萜烯会干扰 MOAH 的分析。因此，本研究中开发了一种改良的 pSPE，称为银离子平面固相萃取（Ag-pSPE）。发现硝酸银（AgNO）浸渍薄层层非常成功地保留了角鲨烯和β-胡萝卜素。植物油经皂化后进行 MOAH 分析，重复性良好（相对标准偏差（%RSD）<10%），在 4.5mg/kg 的加标水平下回收率为 73.4-112.4%（n=4）。对于 MOSH 分析，氧化铝简单的固相萃取（SPE）净化可在 Ag-pSPE 之前去除天然正烷烃。MOSH 的回收率为 55.3-84.5%，%RSD<11%，在 45.5mg/kg 的加标水平下（n=4）。MOSH 的决策限和定量限分别为 7.2 和 22.2ng/zone，MOAH 的决策限和定量限分别为 1.1 和 3.4ng/zone，分别对应于最近引入的 pSPE 方法，表明分析物不受 HPTLC 板上 AgNO 浸渍的影响。与 LC-GC 的方法比较结果表明，MOSH 的结果相似，而 Ag-pSPE 测定的 MOAH 量较高。
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