Ancient objects, chemical analysis

Chemical Analysis. The chemical composition of ancient objects is important for their authentication. The nature as well as the relative amounts of major, minor, and trace elements in any object are of use for determining the authenticity or otherwise of ceramics, glass, or alloys. A wide range of analytical techniques, depending on the nature of the material studied, have been used for this purpose, including X-rays fluorescence analysis, mass spectrometry, atomic absorption spectroscopy, and neutron activation analy-... 

Differences in chemical compositions usually provide new information about artifacts. By differentiating between the sources of the raw materials used to produce objects, it is possible to infer cultural contacts. For some artifacts, detailed studies of compositional differences can also help us understand production methods. The remains of the humans themselves may also be analyzed to provide useful information. The contributions that chemists have made in the study of archaeological materials have gone far beyond the simple chemical analysis of the materials. This volume gives but a small part of the great contributions that chemists have made toward the understanding of ancient materials and technologies. 

It is important to indicate that between natural inorganic pigments, hematite a- Fc203 red is included. In ancient times the chemical analysis of caves paintings indicates that hematite among the iron oxides, was used as pigment. This explains the use of these and other minerals to create cave paintings, decoration of ceramic objects for the preservation of the history of human existence. [2, 14]... 

Proton activation analysis (PAA) provides chemical composition of the materials at a depth of 300-500 pm under the irradiated surface. This technique has been used in the study of metallic objects such as ancient coins [27]. 

In some cases, activation analysis may be regarded as a nondestructive method, i.e., the sample is not significantly altered, neither visually nor chemically. This attribute is obviously exploited in the aforementioned sequential multielement determinations. It is a valuable characteristic for situations where the sample needs to be preserved, such as forensic objects or irreplaceable historical samples, such as ancient coins or paintings. For general analytical practice, this valuable feature can allow reactivation for the determination of additional elements or for full reanalysis, as well as the use, with appropriate precautions, of another analytical method. 

Several other valuable publications have recently appeared on the use of RNAA for trace elements in metals, e.g., the analysis of Na and K in W-Ti alloys by Kim et al. (1998) and trace elements in ancient gold objects by Olariu et al. (1999). Postirradiation RNAA methods separating a single element have the advantages that low detection limits as well as high analytical accuracy can be achieved when results are corrected for chemical losses and all possible interferences are taken into consideration. 

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