Spelling suggestions: "subject:"arganic compounds -- 2analysis."" "subject:"arganic compounds -- 3analysis.""
11 |
The Analysis of Volatile Impurities in Air by Gas Chromatography/Mass SpectrometryTalasek, Robert Thomas 05 1900 (has links)
The determination of carbon monoxide is also possible by trapping CO on preconditioned molecular sieve and thermal desorption. Analysis in this case is performed by gas chromatography/mass spectroscopy, although the trapping technique is applicable to other suitable GC techniques.
|
12 |
In situ chemical analysis of tattooing inks and pigments : modern organic and traditional pigments in ancient mummified remainsPoon, Kelvin Weng Chun January 2008 (has links)
At various points in human history, tattooing has been ubiquitous on almost every continent on Earth, used for reasons of aestheticism, religious beliefs or for social purposes. To study the art of tattooing with respect to a particular culture, one must always be critical to any references to the practice (written, pictorial or artefactual) due to issues of translation and misinterpretation. Complete verification may only come with the discovery of actual tattooed human remains. In combination with artefactual and anthropological evidence, these remains not only provide physical proof of the practice in a culture's ancestry but also possess the ability to link various other forms of physical evidence, which on their own would remain speculative. By its very nature, tattooing may only exist while the bearer is alive. Once the owner dies, the skin, along with the tattoo, decomposes (under normal decomposition conditions) and is lost forever. However, tattoos may survive if the dermal layers of the skin are preserved, either by natural or artificial means. The processes of mummification in various civilisations have provided us with a rare opportunity to study the art and processes of tattooing in antiquity. Existing tattooed mummified remains have been found in: Egypt; Siberia; Eastern Central Asia; Greenland; Alaska and St. Lawrence Islands; Central Andes (Peru and Chile); Philippines; New Zealand and Italy. Existing literature regarding the analysis of tattooing inks and pigments once deposited into the skin is very limited. Comparatively, the industrial organic pigments used to colour the majority of modern tattooing inks sold today have not been officially approved by any regulating body and as such, manufacturers are not required to disclose the chemical ingredients of their products. Chemical identification of these tattoo pigments post-procedure will aid medical practitioners in the event of complications or for the purposes of tattoo removal. Forensically, tattoos are often one of the distinguishing features used in the identification of victims of crime or accidents. Experiments were carried out using an animal model (Sus scrofa) for the tattooing. Given the theoretically large but ultimately limited range of substances available to both ancient and modern tattooists, the premise of the experiment involved surveying the literature regarding possible tattooing pigments and either obtaining or reproducing a careful selection of these in the laboratory. These pigments were then tattooed onto the ii animal model and after allowing for the essential healing period, the tattooed areas were excised, with those tattooed with traditional pigments subjected to various simulated mummification environments.
|
13 |
The context of organic residues in archaeological vessels of ceramic and BronzeMerriman, Kristine Roberta January 2014 (has links)
Since the 1970s, the study of molecular organics preserved in archaeological ceramics, commonly referred to as organic residue analysis, has been used to infer vessel use and study dietary, economic, and ritual activities in the past. The purpose of this project is to analyse organic residues from a variety of ancient vessels and attempt to understand further the relationship between molecular organic preservation and vessel characteristics. It has been previously assumed that the absorption of these organics in the ceramic matrix is predominantly responsible for their preservation. The clarification of this or other preservative mechanisms and the further understanding of the relationships of vessels with their contents has a direct impact on the interpretation of organic residues and vessel use. The first section addresses the preservation of molecular organics in pottery vessels from Tel Kabri, Israel; Tel Megiddo, Israel; and Lefkandi, Greece. The one hundred and thirty-three samples from these three sites represent vessels used in domestic, burial, ritual, and elite contexts from the Early Bronze Age through the Iron Age Eastern Mediterranean. The focus of the study is the quantification of residue yields and identification of potential links with vessel properties and characteristics of the ceramic samples. Sequential extractions using two methods, conventional chloroform/methanol solvent extraction and direct FAME extraction/derivatisation, were applied to the sherds to test the absorption and adsorption of organics into ceramic materials. The majority of samples were tested non-destructively, enabling the comparison of residue yields to certain vessel properties and characteristics displayed in the same sherds. Where available, data concerning vessel form, sampling location on the vessel profile, thickness measurements were recorded, and XRF measurements were taken, with this in mind. The second section investigates the question of whether bronze and copper alloy vessels have the capability to preserve molecular organics within their corrosion products. Twenty-two samples of corrosion and associated material from five Early Roman bronze vessels found in cremation burials during the A2 Pepperhill to Cobham project in County Kent, United Kingdom were studied for organic material. These samples provide some of the first evidence that the residues of original content are preserved in copper alloy vessels either through entrapment in or reactions with copper corrosion.
|
Page generated in 0.0926 seconds