Thermo nicolet avatar ft ir

The progress of reactions was routinely monitored by thin-layer chromatography (TLC) on silica gel plates (pre-coated Merck^®), and spots were examined under the UV light (254 nm). Melting points were measured by open capillaries using a Stuart Scientific electro-thermal melting point apparatus (UK). FT-IR spectra were recorded on Thermo-Nicolet Avatar FT-IR (Thermo Fisher Scientific, Rockville, MD). ¹H and ¹³C NMR spectra were recorded on 400 MHz Avance Ultrashield spectrometer (Bruker, Ettingen, Germany) in DMSO-d₆ in part per million (δ) using trimethylsilane as an internal standard. Mass spectra were measured in a positive ion mode using the electrospray ion trap (ESI) technique on a Bruker Apex-4 instrument (Germany).

The compatibility and interactions between PG and the components of the formulation were investigated using a Thermo Nicolet AVATAR FTIR instrument (Thermo-Fisher, Waltham, MA, USA). For the investigation, pellets were prepared by co-grinding 10 mg compound with 150 mg potassium bromide (KBr) and compressed with 10 tons using a hydraulic press. The FTIR spectra were measured over the range of 4000–400 cm⁻¹ with a resolution of 4 cm⁻¹ for 128 scans. The recorded spectra were reported as absorbance as a function of wavenumber.