WDXRF analysis of Iberian potsherds from the Late Iron Age

Method

The outer surfaces of all the samples were mechanically removed prior to analysis.

The samples were heated to 950°C for one hour after 24h drying at 50°C, weighted for LOI calculation and ground in a tungsten carbide mortar. 0.8 g of powder was mixed with 3.2 g of Spectroflux 110 flux (Johnson Matthey; 33.5% metaborate and 66.5 % lithium tetraborate) and melted in gold-platinum crucibles with an autofluxer melting device (Breitländer).

The data were collected with a SRS 3400 (Bruker) spectrometer of 3 kW power (working at 60 kV, 100 mA max.). The spectrometer was equipped with a rhodium tube window, four analyser crystals (OVO-55, LiF200, LiF220, PET), two collimators (0.46° and 0.15°) and two sensors (a proportional Ar/CH4 gas-flow counter and a scintillation counter). The calibration of the instrument was carried out on 40 international certified reference materials.

Data description

  • sample: sample reference;
  • date: date of the analysis;
  • laboratory: analysis laboratory;
  • stratigraphy: stratigraphic unit (all dated to the first half of the 1st century BC);
  • artefact: typology;
  • part: analysed part of the artefact;
  • LOI: loss on ignition (percent);
  • CaO, Fe2O3, TiO2, K2O, SiO2, Al2O3, MgO, MnO, Na2O, P2O5: oxide mass percents;
  • Zr, Sr, Rb, Zn, Cr, Ni, La, Ba, V, Ce, Y, Th, Pb, Cu: ppm.

Data below the following limits should be considered unreliable:

  • Na2O: 0.5 %
  • La: 24 ppm
  • Y: 15 ppm
  • Th: 15 ppm
  • Pb: 20 ppm
  • Cu: 10 ppm
Nicolas Frerebeau
Nicolas Frerebeau
Archaeologist

Technological choices in ancient societies.