Nicolet nxr 9650 ft raman spectrometer

Samples of whole kernels were preliminarily prepared by grinding in a mortar and next used for HPLC (Agilent Technologies, Woldbron, Germany) and electrophoresis analysis (Hoefer, Holliston, MA USA) as well as FT-Raman analysis of biochemical components (Thermo Scientific Nicolet NXR 9650 FT-Raman spectrometer, Waltham, MA, USA) measurement.

FT-Raman spectra were recorded using a Nicolet NXR 9650 FT-Raman spectrometer (Thermo Fisher Scientific, USA) equipped with an Nd:YAG laser (1064 nm) and a germanium detector. Measurements were performed in the range from 150 to 3.700 cm⁻¹ with a laser power of 1 W. Unfocused laser beam was used with a diameter of approximately 100 μm and a spectral resolution of 8 cm⁻¹. Raman spectra were processed by the Omnic/Thermo Scientific software based on 128 scans. The obtained spectra were normalized using vector normalization in OPUS 7.0 software (Bruker Optik GmbH, Ettlingen, Germany). Moreover, each spectrum was smoothed using the Savitzky–Golay algorithm. The number of smoothing points was nine.

Seedlings from the previous assays were lyophilized and stored at −80 °C until use. The Raman spectra of lyophilized seedlings were recorded in the endosperm of kernels cut in half using a Nicolet NXR 9650 FT-Raman Spectrometer (Thermo Scientific, Walthman, MA, USA) equipped with an Nd: YAG laser (1064 nm) and an InGaAs detector. The measurements were performed according to the method described by Troć et al.^{45 (link)} at room temperature at a spectral resolution of 8 cm⁻¹ using an unfocused laser beam approximately 50 μm in diameter and an aperture of 80 μm. The laser power was 0.5 W, and the measurement range was 400 to 2000 cm⁻¹. For each object 64 scans per spectrum were performed. The Raman spectra were registered and processed using the Omnic/Thermo Scientific software program (Thermo Scientific, Walthman, MA, USA). Six spectra from different plants were collected and averaged for each plant species and treatment. The spectra were baseline corrected. A hierarchical cluster analysis (similarities between FT-Raman spectra) was used to group the studied objects into clusters to find significant and systematic differences in the measured FT-Raman spectra and was performed using Statistica ver. 13.3 (TIBCO Software Inc., Palo Alto, CA, USA) for the whole wavenumber range. The spectral distances were calculated using Ward's algorithm.