Archaeometry

The main objective of the Archaeometry Laboratory is the characterization of materials, based on the study of their chemical and mineralogical composition, and their vibrational and thermal analysis. It seeks to support research in the areas of geology, archeology, heritage, chemistry, and pharmacy, as well as to provide services in the fields of construction, civil engineering and nanomaterials.

It is outfitted with the required equipment to conduct non-invasive analyses, without the need for the prior physical and chemical preparation of the sample, without altering the surface on which the analysis is carried out. There is also portable equipment for field use

Methods

This laboratory has various analytical techniques for the characterization of solids, such as: i) x-ray crystalline powder diffraction, ii) x-ray fluorescence spectrometry, iii) Raman spectroscopy, iv) infrared spectroscopy and v) thermal analysis. A brief description of the fundamentals of each technique is presented below:

  • x-ray crystalline powder diffraction
  • x-ray fluorescence spectrometry
  • Raman spectroscopy
  • infrared spectroscopy
  • thermal analysis.

Sample preparation area

Samples are prepared at this laboratory for their study based on x-ray diffraction of crystalline materials (samples of powder and/or oriented aggregates) and x-ray fluorescence (glass beads and tablets).

X-ray spectroscopy area

  • X-ray crystalline powder diffraction

X-ray diffraction (XRD) is one of the most useful techniques for the qualitative and quantitative analysis of organic and inorganic solid crystalline phases in powder samples.

  • Wavelength dispersive X-ray fluorescence spectrometry:

X-ray fluorescence is a technique that enables the chemical elemental analysis, of the elements between F and U, of solid substances.

The most common manner of conducting this test is based on the preparation of a glass bead, when the objective is the analysis of majority elements, or a tablet, which is most appropriate for trace elements.

Raman and Infrared Spectroscopy Area

  • Raman spectroscopy

This is an analytical technique that can provide molecular information on organic and inorganic substances, enabling their identification.

  • Infrared spectroscopy

This is an instrumental analytical technique that enables identification of the main functional groups of the molecular structure of a compound.

Thermal Analysis Area

Thermal analysis enables the identification, purity control and stability of different materials, given that state transitions occur at temperatures that are characteristic to each of them.

Facilities and equipment

Powder diffractometer

X´Pert PRO MPD PANalytical equipped with a Cu anode X-ray tube, which operates using Theta-Theta geometry, programmable divergence slit, secondary curved monochromator and ultra-fast PIXcel detector. It can work with a 15-position autosampler for powder samples or a multipurpose platform, which enables the non-invasive analysis of large samples directly.

Wavelength Dispersive X-ray Fluorescence Spectrometry

Axios PANalytical equipped with a Rh anode x-ray tube (4kW), with flow and scintillation detectors and 5 analyzing crystals. It has an automated robotic system for sample analysis. In addition to the quantitative determinations, it boasts OMNIAN software that makes it possible to obtain a semi-quantitative analysis of any type of solid sample.

Portable X-Ray Fluorescence Spectrometry

NITON XL3t 950 He, equipped with a 50 kV Ag anode x-ray tube and a SDD Silicon detector. It can work with helium, to lower the detection limits of the light elements. It is a portable device, equipped with everything necessary (device case, sample preparation case and tripod) for field work to conduct in situ analyses (altarpieces, caves, museums, soils). The device is also free-standing thanks to a stand to take measurements, meaning that it can be used by any applicant.Equipo 3

Confocal Raman Microscope

DXR Thermo Fisher. It is composed of a Raman spectrometer coupled to an Olympus confocal microscope and two lasers with excitation wavelengths of 532 nm (green) and 780 nm (NIR). It has a CCD detector, cooled using a Peltier effect. The confocality control is particularly noteworthy, as it makes it possible to select the focal plane of acquisition of the Raman signal. The device has a fiber optic probe so that samples can be taken outside of the cavity of the microscope, which is particularly useful for the study of large samples.

Fourier Transform Infrared Spectrometer

Nicolet 6700 Thermo Fisher. It has a KBr beam splitter and a DLaTGS detector that can record FT-IR spectra in the mid-infrared range (4000-400 cm-1) with a spectral resolution of up to 0.5 cm-1. It has accessories for different types of measurements: solids through transmission (KBr) and diffuse reflectance, solids and liquids using diamond ATR, gases through the TGA-IR interface which connects the spectrometer to a thermobalance.

Simultaneous Thermal Analyzer (ta instrument) (tga/dsc)

Q600 TA Instruments, equipped with a horizontal furnace that makes it possible to simultaneously measure weight and heat flow variations, from room temperature to 1400ºC. This device is coupled via an interface to an infrared F-TIR spectrometer, which also facilitates the simultaneous analysis by infrared spectroscopy of the gases produced in the decomposition of the substances studied.Equipo 1

Simultaneous Thermal Analyzer (netzsch) (tga/dsc)

STA 449 F5 Netzsch, device with a vertical furnace, making it possible to simultaneously measure weight and heat flow variations of the sample, from room temperature to 1400ºC. The device is equipped with a 20-position sample changer. It also has a rotary vacuum pump to clean the furnace between samples.

Applications and Services

Applications

Geology and Archeology

  • Characterization of rocks, soils, minerals, gems, etc.
  • Study of the origin of stone artefacts.

Cultural Heritage

  • Characterization of pigments in works of art (paintings, sculptures, documents), both at the laboratory and at their original location (museum, altarpiece, cave).

Industrial Analysis

  • Study of graphene and graphite oxides.
  • Identification of compounds for the pharmaceutical and cosmetics industry.
  • Chemical elemental analysis of slag, flux, cement, etc.

Services

  • Identification of phases on geological, archaeological and industrial samples.
  • Separation of fine fractions and study of clay mineralogy in oriented aggregates (thermal and chemical treatments).
  • Study of phases on the original sample, without the need for prior preparation (non-invasive analysis), which is extremely useful for archaeological samples.
  • Chemical elemental analysis of geological, archaeological and industrial samples.
  • Chemical elemental analysis conducted on the field with a portable FRX analyzer. Equipment rental is possible.
  • Pharmaceutical analysis: identification of active substances and excipients in a variety of formulations.
  • Study of decomposition, thermal stability and phase transitions in different gas atmospheres (inert, oxidant) from room temperature to 1600ºC.
  • Gas measurements through the TGA-IR interface, which conducts a real-time analysis of the substances that are released during the thermogravimetric tests.