文物中蜡类材料的热裂解-气相色谱/质谱识别

为识别文物中蜡质原材料,以及文物保护修复工作中常用蜡类材料的类别,研究通过在线甲基化热裂解-气相色谱/质谱联用技术对蜂蜡、棕榈蜡、小烛树蜡、地蜡、石蜡等蜡类材料进行分析检测。研究发现:蜂蜡的主要裂解产物为直链烷烃、直链脂肪酸、直链醇、含羟基脂肪酸;棕榈蜡为直链醇、直链脂肪酸、脂肪酸衍生物;小烛树蜡为直链烷烃、直链脂肪酸、直链醇、羽扇豆醇及其衍生物、计曼尼醇及其衍生物、脂肪酸衍生物;地蜡、石蜡等矿物蜡的主要裂解产物为直链烷烃。不同蜡中裂解产物的种类及其相对含量分布规律均有所区别,因此通过在线甲基化热裂解-气相色谱/质谱联用技术可以实现不同种类蜡的区分。通过所建立的方法及总结的数据,研究推断故宫旧藏清代紫檀木边座嵌玉人鸂鶒木山水图插屏中镶嵌珐琅构件所用棕色蜡为蜂蜡,所用白色蜡为矿物蜡及少量蜂蜡。本研究所建立方法易于推广,适用于文物中蜡类材料的准确、快速识别。     

Identification of psychoactive alkaloids in ancient Andean human hair by gas chromatography/mass spectrometry

Various ethnographic sources have demonstrated the symbolic and ritualistic importance of psychoactive plants in Native American societies. The social milieu of these mind- altering plants appears to be ancient. Archaeological evidence during the Tiwanaku empire expansion along the Atacama Desert of Chile, circa 500–1000 A.D., shows the presence of highly decorated snuffing tablets and tubes as grave goods. The preservation of mummified human bodies in the Azapa Valley, northern Chile, provided an opportunity to test the exact nature of the psychoactive plants used in this region. Using gas chromatography/mass spectrometry (GC–MS), here we show that ancient Andean populations from northern Chile consumed Banisteriopsis, a vine that contains harmine. This is the first direct archaeological evidence of hallucinogenic and medicinal ethnographic practices. Interestingly enough, this rainforest plant does not grow along the Atacama coast, thus our findings suggest extensive plant trade networks in antiquity as far as the Amazon.     

木材中挥发性有机酸的SPMEGC/MS分析研究

采用木材制作的藏展空间,木材释放出的挥发性有机酸,在一定的温湿度条件下,会对文物造成不良的影响,因此需要建立一套对木材挥发性有机酸测定的方法.为此,采用固相微萃取(SPME)样品预处理技术,分离富集木材中的挥发性有机物,结合气相色谱-质谱(GC/MS)联用技术对木材中挥发性有机酸进行半定量分析,研究了9种木材中挥发性有机酸的挥发量和分布规律.结果表明,不同木材有机酸的挥发量差别较大.实验结果可为博物馆在装修和储藏中对材料的筛选提供科学依据.     

热裂解-气相色谱/质谱在文化遗产研究中的应用进展

色谱和质谱联用技术是有机物常用的一种分析方法,在文物保护与考古残留物研究等方面的应用已有几十年的发展。色谱与质谱联用分析样品时,需要对样品进行水解提取、衍生化等前处理,这个过程较繁琐,且耗时长,另外在样品处理过程中还有样品流失的情况发生。因此,现在一般采用热裂解-气相色谱/质谱联用技术(pyrolysis-gas chromatography/mass spectrometry,Py-GC/MS)来分析有机质样品。Py-GC/MS在分析样品时有如下优势:无需对样品进行前处理,样品可直接进行热裂解分析,操作比较简单;灵敏度高,能实现多组分混合有机样品识别;需要样品量很少,可满足文物样品微损分析检测的要求。因此,该方法在文化遗产保护和考古有机残留物识别鉴定中发挥了重要的作用。     

Indications of embalming in Roman Greece by physical,chemical and histological analysis

The partially mummified remains of a high-status female (ca. 1700 BP, Thessaloniki, Greece) were found inside a Roman-type marble sarcophagus containing a lead coffin. The individual was positioned on a wooden pallet, wrapped in bandages, and covered with a gold-embroidered purple silk cloth. Besides the clothes, remnants of soft tissue as well as the individual's original hair style and eyebrows were exceptionally well preserved. In addition to the macroscopic examination, microscopic and biochemical analyses were undertaken. Scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) analysis, and gas chromatography/mass spectrometry (GC/MS) were applied to examine the tissue preservation and probable mechanisms of mummification. The presence of chemical components, such as sesquiterpenes, triterpenoids, and diterpenoids, originating from coniferous and pistacia resins, myrrh, and other spices, verify ancient information on preparation methods of the dead in Greek and Roman times. These chemical components are thought to have played a prominent role in the mummification mechanism in this particular case. The potential effect of the lead coffin in the mummification process was also examined. Energy-dispersive X-ray analysis failed to detect lead penetration into the tissues, suggesting that the coffin played a limited role in the preservation of soft tissue.     

应用热辅助水解甲基化裂解气相色谱质谱技术对古代漆器漆膜的分析研究

为了改良漆器漆膜的性能,古代漆工在制作过程中通常向生漆中加入干性油等添加剂。为了确定生漆及添加剂的种类,本工作采用四甲基氢氧化铵(TMAH)作为甲基化试剂,利用热辅助水解甲基化裂解气相色谱质谱(THM-Py-GC/MS)技术对所选的参考样品进行分析,然后将成熟的方法和实验条件应用到古代漆器的分析研究中。在古代样品中检测出了3-十五烷基邻苯二酚(C15)、3-十五烯基邻苯二酚(C15:1)等来源于中国、日本地区种植的Rhus vernicifera树种的生漆的特征热裂解化合物,确定了所用生漆的种类。另外,本实验在古代漆器中检测到了棕榈酸、硬脂酸、庚酸、辛酸和壬二酸等脂肪酸,推断该漆膜中添加了干性油。利用三维视频显微镜、扫描电镜、X射线衍射分析方法发现古代漆器采用了在胎体上依次髹漆灰、底漆和色漆的髹漆工艺,其中漆灰主要由漆液和钠长石、石英调制而成,黑色漆膜的呈色颜料为含铁化合物,揭示了古代漆器的髹漆工艺。该研究结果不仅增强人们对古代漆器制作材料和工艺的科学认知,而且为保护漆器这一独特的文化遗产提供科学依据。     

故宫博物院旧藏漆器文物中漆灰材质的科学研究

漆灰的修复是漆器文物修复工作的重要组成部分。为揭示故宫博物院旧藏漆器3种典型漆灰的材料构成及特点,以及为漆器修复工作提供科技支持,研究结合X射线荧光光谱、微区X射线衍射、红外光谱、纤维显微镜观测、热裂解-气相色谱/质谱联用等技术,综合分析了3种典型漆灰所含无机及有机原材料。研究结果表明：明代古梅花蕉叶式琴漆灰所用无机材料是动物角灰或骨灰及少量黏土,胶结材料则由中国大漆及少量植物油组成;清代黑漆描金大宝座漆灰的无机材料为含有方解石的黏土,胶结材料为熟桐油、猪血的混合物,此外,样品中还含有麻类纤维,为宝座木胎与漆灰层之间所裱麻布,宝座漆灰不但能提供平整髹漆表面,而且还对麻布有加固定型作用;清代黑漆地填金字张廷玉书圣训天伦对联漆灰的无机材料为黏土,胶结材料则为熟桐油、猪血的混合物。研究所用分析方法体系可实现漆灰原材料,特别是有机胶结材料的准确识别。3种典型漆灰的选材特点与中国古代漆器,特别是明清时期家具、器物制作用料传统相吻合,研究结果可直接应用于漆器文物修复方案的制定。