Vertex 80v ftir spectrometer

All linear absorption measurements were performed using a Bruker Vertex 80v FTIR spectrometer, equipped with a liquid-nitrogen-cooled mercury-cadmium telluride (MCT) detector. The spectra were recorded under a nitrogen atmosphere at a wavelength resolution of 3 cm⁻¹. For every spectrum, 100 scans were averaged. In all measurements, a standard sample cell with a path length of 10–50 μm was used. The reported spectra were corrected for the absorption of the solvent background.

FT-IR spectroscopic analysis was performed directly on the previous EVT2 samples at the Planetary Emissivity Laboratory of DLR in Berlin.
Spectra were recorded in triplicate on the Vertex 80v FT-IR Spectrometer (Bruker) in reflectance mode and read at a resolution of 4 cm⁻¹ in the wavenumber region of 400–10,000 cm⁻¹ with Spectragryph software [39 ]. Measurements have been performed under evacuated atmosphere to remove atmospheric features from the spectra.
For analyzing the presence of specific organic molecules, the region of interest, 600–4000 cm⁻¹, was cropped.

The measurements were performed using a Vertex 80v FTIR spectrometer (Bruker Corp., Ettlingen, Germany) equipped with a liquid nitrogen cooled MCT-detector (D* = 4 × 10¹⁰ cm Hz^0.5 W⁻¹ at 9.2 μm). The custom-made temperature-controlled cell was equipped with a 53 μm-thick PTFE spacer. The sample compartment of the spectrometer was continuously flushed with dry air during IR measurements. IR spectra were acquired with a spectral resolution of 2 cm⁻¹ in double-sided acquisition mode using a Blackman-Harris 3-term apodization function and a zero filling factor of 2. For PLL measurements, a total of 450 scans were averaged per spectrum (total measurement time = 100 s), acquired in a temperature range of 20–50 °C (ΔT = 2 °C). After setting the temperature, the cell was allowed to equilibrate for 240 s prior to spectrum acquisition. Following this procedure, the heating rate was the same as for QCL-IR measurements. Protein measurements were carried out at 25.0 °C and a total of 64 scans were averaged per spectrum. Spectra analysis was performed by using the software package OPUS 7.2 (Bruker Corp., Ettlingen, Germany). If necessary, absorption bands of water vapour in the atmosphere were subtracted.