Description

The Instrumental Analysis service groups several laboratories for analysis and characterization of samples. Each laboratory has specific technical personnel and scientific advisors.

X-Ray diffraction

The XR Difraction Unit is commited to the Quality Assurance Letter, approved on 09-10-2019.

X-ray diffraction analysis is used for mineralogical (phases identification, quantitative phase estimation) and crystallographic analysis and of any solid material. XRD is widely used in inorganic materials, superconductors. Organic compounds, cements and concrete, minerals, corrosive materials, metals and alloys, polymers, pigments, forensic samples, pharmaceutical products, ceramics, explosives, etc.

The XRD laboratory is equipped with a PANalytical X’Pert Pro diffractometer for powder samples, with Cu anode X-ray tube, programmable incident slit, spinning sample stage to reduces preferred orientation effects, and RMS X’Celerator solid state detector. The lab is focused on phase identification and quantitative estimation on power samples, using X’Pert High Score software.

Routine analyses are performed on powder samples and oriented mounts of clay minerals (including several chemical and thermal treatments).

Responsible technician: Elvira Martín Medina
Scientific advisor: Cristóbal Verdugo Escamilla
Service requests: difraccion@iact.csic.es

XR Fluorescence Unit

The XR Fluorescence Unit is commited to the Quality Assurance Letter, approved on 12-10-2018.

The laboratory is equipped with a wavelength dispersive X-ray fluorescence spectrometer, BRUKER S4 Pioneer, with a maximum power of 4 kW. The spectrometer has an Rh anode X-ray tube (60 kV, 150 mA); three analyzer crystals (OVO-55, LiF 200 and PET); two collimators, 0.23° and 0.46°; Pb, Cu, and Al beam filters; and a flow proportional counter for light element detection and a scintillation counter for heavy elements. The Integrated Analytical Intelligence (IAI) of SPECTRAplus, the analytical X-ray fluorescence (XRF) software solution for calibration, evaluation and reporting, offers easy start-up for own calibrations, providing optimized measurement parameters and allowing easy routine operation. The integrated standardless evaluation for all kind of samples like rocks, minerals, metals, hydrocarbons and all kind of industrial products allows the fast and easy determination of element concentrations from 100 % down to the ppm-level without performing a calibration.

Sample preparation equipment include:

• Automatic hydraulic press (NANNETTI MIGNON S,), to prepare pressed pellets.
• Fusion machine (FLUXANA-HD-ELEKTRONIK Vulcan 4M), to prepare fused beads.
• Precision balance (GF-200, AND)

Routine analyses are performed on fussed beds and pressed pellets.

Fussed beads

Silicate matrixes: Analysis of major elements (SiO2, TiO2, Al2O3, Fe2O3T, MnO, MgO, CaO, Na2O, K2O, P2O5), LOI and some elements in trace amount (Zr, Sr, Ni, Cr). The empirical calibration is based on a set of more than 20 international geostandard samples, that include a wide range of common silicate rocks. Residual matrix effects after simple dilution in the fussed bead (1:19) are corrected by variable influence coefficients (alpha). Detection limit for the element in trace amount is in the order of 10 ppm. For major elements precision is better than 0.2-0.3 % (for Na2O, 0.5%).

Carbonate matrixes: Analysis of major elements (SiO2, TiO2, Al2O3, Fe2O3T, MnO, MgO, CaO, Na2O, K2O, P2O5) and LOI. The empirical calibration is based on a set of more than 14 certified geostandards of carbonate rocks (limestones and dolostones). Precision is better than 0.2-0.3 % (for Na2O, 0.5%).

Pressed pellets

Analysis of elements in trace amounts in silicate matrixes (V, Cr, Co, Ni, Cu, Zn, Ga, Rb, Sr, Y, Zr, Nb, Ba, Pb, Th .). The empirical calibration is based in a set of 25 international geostandards that include the most common silicate rocks. Analysis conditions are optimized to get detection limits of 2-4 ppm depending on the element (10-15 for Ba and Co). Matrix effects are corrected using an analysis of mayor elements and variable influence coefficients (alpha) derived from fundamental parameters.

Standarless or fundamental parameter analysis procedure for mayor and in trace elements. A number of peaks of elements are scanned to detect its presence and estimate its concentration. The quantitative estimation is based on fundamental parameter and no standards are used. The method is applied to unknown matrixes or those not include in our calibration procedures, to mineralized rocks, compositions out of standard calibrations, or samples inadequate to prepare fussed beads. Analytical errors are higher than errors in empirical calibration procedures.

Responsible technician: Carmen Fátima López Rodríguez
Scientific advisor: Francisca Martínez Ruiz
Service requests: fluorescencia@iact.csic.es

Thermal and Thermogravimetric Analysis

Thermal analysis allows measuring the changes in mass and thermal effects that a sample undergoes in a given temperature range. The thermal analysis laboratory is equipped with highly flexible and sensitive Netzsch STA449 Jupiter F5 equipment. It allows thermogravimetric analysis (TG), differential thermal analysis (DTA), and differential scanning calorimetry (DSC) to be performed individually or simultaneously. Samples are analyzed under nitrogen (inert) or air (oxidizing) atmosphere. It allows the analysis of minerals, inorganic compounds, and organic compounds from room temperature to high temperature and allows the programming of static and dynamic temperature treatments at different heating rates. The amount of sample required can be up to 5 mg, depending on its nature.

Responsible technician: Eduardo Flores Ruiz
Scientific advisor: F. Javier Huertas Puerta
Service requests: analisis_termico@iact.csic.es

ATR-FTIR spectroscopy

Fourier transform infrared spectroscopy (FTIR) provides structural and chemical information on inorganic and organic samples. It is a very versatile technique and requires the use of very small amount of sample (1-2 mg), which are diluted within a KBr matrix. The analysis is performed by measuring the transmitted radiation.

Attenuated total reflectance (ATR) is a measurement technique used with an infrared spectrometer based on attenuated total reflection. The beam of infrared light undergoes total internal reflection within the glass of the accessory, reflecting off the surface on which the sample is deposited. The signal comes from the sample surface since the penetration depth of the radiation is less than 2 µm, which facilitates the analysis of adsorbed substances. The use of analyzer crystals with multiple reflections helps to amplify the intensity of the absorption signal. This technique allows the analysis of solid samples without manipulation. The sample quantity is larger than with KBr pellets and depends on the size of the measuring cell.

The laboratory is equipped with a Perkin Elmer SpectrumOne FTIR spectrometer. It allows measurement in the mid-infrared, in the range 400-4000 cm^-1, with a resolution of 0.5 cm^-1.

The accessory ATR is a Perkin Elmer flat horizontal cell, with a 9-bounce zinc selenide crystal.

Responsible technician: Eduardo Flores Ruiz
Scientific advisor: F. Javier Huertas Puerta
Service requests: espectroscopia_ftir@iact.csic.es

BET Specific Surface Area Determination

The specific surface area and pore size distribution in porous materials are analyzed by adsorption isotherms of an inert gas, such as nitrogen, at 77 K. The specific surface area is determined by the method developed by Brunauer, Emmett and Teller. The pore size distribution and pore area are obtained by applying different models to the adsorption isotherm.

The laboratory has a Beckman Coulter SA3100 benchtop unit using the static dosing method. The unit has three vacuum degassing stations and an analysis port. Helium is used to measure the cell void space.

Responsible technician: Eduardo Flores Ruiz
Scientific advisor: F. Javier Huertas Puerta
Service requests: superficie_bet@iact.csic.es