Brassicaceae seed oil identified as illuminant in Nilotic shells from a first millennium AD Coptic church in Bawit, Egypt
Brassicaceae seed oil identified as illuminant in Nilotic shells from a first millennium AD Coptic church in Bawit, Egypt
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埃及巴维特公元一千年科普特教堂的尼罗河贝壳中发现十字花科种子油是发光剂
DOI：
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发表时间：
2008
影响因子：
4.3
通讯作者：
M. Waelkens
中科院分区：
文献类型：
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作者：
K. Romanus;W. Neer;E. Marinova;K. Verbeke;A. Luypaerts;S. Accardo;Ive Hermans;P. Jacobs;D. Vos;M. Waelkens
在埃及巴维特科普特修道院的一座公元八世纪至十世纪的教堂中，人们在大型尼罗河双壳类 Chambardia rubens 的贝壳内发现了烧焦的油脂沉积物，据说被用作油灯。对残留物进行色谱残留物分析技术的组合。通过气相色谱 (GC) 分析甲基化提取物中不饱和脂肪酸的浓度相当高，表明存在植物油。对甲酯的稳定碳同位素（δ13C 值）的分析也表明植物比动物更适合作为脂质来源。在通过 GC 结合质谱法对甲硅烷基化提取物寻找生物标志物时，发现了一系列二酸以及高浓度的 13,14-二羟基二十二烷酸酯和 11,12-二羟基二十烷酸酯。这些化合物是芥酸和金刚鱼酸的氧化产物，它们大量存在于十字花科植物的种子中。液相色谱与质谱分析显示未改变的甘油三酯浓度较低，但显示出大量具有至少一个二羟基化酰基链的甘油三酯。二羟基化甘油三酯和α,ω-二羧酸的异常保存可能与干燥保存条件有关。对二羟基脂肪酸的立体异构体的分析可以确定氧化是否发生在燃料燃烧期间或之后。结果证明，在早期伊斯兰埃及，油菜籽油（Brassica napus L.）或萝卜油（Raphanus sativus L.）被用作照明剂，不仅陶瓷灯，而且软体动物的壳也被用作燃料容器。
Burned greasy deposits were found inside shells of the large Nile bivalve Chambardia rubens, excavated in an eight- to tenth- century AD church of the Coptic monastery of Bawit, Egypt, and supposedly used as oil lamps. The residues were subjected to a combination of chromatographic residue analysis techniques. The rather high concentrations of unsaturated fatty acids, as analysed by gas chromatography (GC) in the methylated extract, suggest the presence of a vegetal oil. Analysis of the stable carbon isotopes (δ13C values) of the methyl esters also favoured plants over animals as the lipid source. In the search for biomarkers by GC coupled to mass spectrometry on a silylated extract, a range of diacids together with high concentrations of 13,14-dihydroxydocosanoate and 11,12-dihydroxyeicosanoate were found. These compounds are oxidation products of erucic acid and gondoic acid, which are abundantly present in seeds of Brassicaceae plants. Liquid chromatography coupled to mass spectrometry analysis showed low concentrations of unaltered triglycerides, but revealed sizeable amounts of triglycerides with at least one dihydroxylated acyl chain. The unusual preservation of dihydroxylated triglycerides and α,ω-dicarboxylic acids can be related to the dry preservation conditions. Analysis of the stereoisomers of the dihydroxylated fatty acids allows one to determine whether oxidation took place during burning of the fuel or afterwards. The results prove that the oil of rapeseed (Brassica napus L.) or radish (Raphanus sativus L.) was used as illuminant in early Islamic Egypt, and that not only ceramic lamps but also mollusk shells were used as fuel containers.