Iron Forms Fe(II) and Fe(III) Determination in Pre-Roman Iron Age Archaeological Pottery as a New Tool in Archaeometry

Abstract

This article presents studies on iron speciation in the pottery obtained from archaeological sites. The determination of iron forms Fe(II) and Fe(III) has been provided by a very simple test that is available for routine analysis involving the technique of molecular absorption spectrophotometry (UV–Vis) in the acid leachable fraction of pottery. The elemental composition of the acid leachable fraction has been determined by inductively coupled plasma optical emission spectrometry (ICP-OES). Additionally, the total concentration of the selected elements has been determined by X-ray fluorescence spectrometry with energy dispersion (EDXRF). The results of the iron forms’ determinations in archaeological pottery samples have been applied in the archaeometric studies on the potential recognition of the pottery production technology, definitely going beyond the traditional analysis of the pottery colour.

A Fast and Efficient Procedure of Iron Species Determination Based on HPLC with a Short Column and Detection in High Resolution ICP OES

“…Pottery is another example of a material that is being studied for iron species, e.g., in black glaze of Chinese pottery [7], Sicilian "proto-majolica" pottery [8], Sicilian antique pots [9], and Brazilian [10] and Polish ceramics [11]. The oxidation state of the element depends on the used clay and the method of firing (temperature, technique).…”

“…Although both iron species are usually present in the material or coating, a higher content of Fe(III) is 2 of 11 observed in red-orange ceramics and Fe(II) in dark grey vessels. Therefore, the Fe(III)/Fe(II) ratio is valuable and meaningful, as it may indicate the method of ceramic production [11].…”

“…Ferrozine assay, described by Stookey [13], is another colorimetric analysis for Fe(II), performed in marine waters [14], sediments, and glacial samples [15][16][17]. 2,2 -bipirydyl and potassium thiocyanate are used for Fe(II) and Fe(III) determination, respectively, and they were applied in food samples [18], soil [19], sediments [20], and ceramics [11]. Unfortunately, colorimetric methods are not very sensitive, as the absorbance may potentially be significantly falsified due to the presence of other compounds, e.g., Fe(III) in Fe(II) determination [21].…”

Curricular Materials on the Chemistry of Pottery, Including Thermodynamic Calculations for Redox Reactions in the 3-Stage Firing Process of Athenian Black- and Red-Figure Vases Produced from the Sixth–Fourth Centuries BCE

“…For examples of such studies, see the review in Zumbulyadis or recent chemical archeology investigations of ancient pottery − and the source terrains for clays , and tempering additives.…”

Advances in Analytical Strategies to Study Cultural Heritage Samples

“…Studies of Fe speciation in archeological ceramics may be critical to gain insights into the various types of clay used and the different techniques and temperatures of clay firing. The study by Kozak et al [6] reports the results of Fe speciation in ceramics obtained from archeological sites. UV-Vis molecular absorption spectrophotometry was used to determine Fe(II) and Fe(III).…”