Avance 2 spectrometer

NMR spectra were acquired with CDCl₃ as solvent on a Brucker Avance II spectrometer, at Centro Grandi Apparecchiature (Palermo, Italy), operating at 400 MHz (¹H) or 100 MHz (¹³C) frequencies. The chemical shifts are reported relative to the chloroform residual peak (7.27 ppm for ¹H NMR).

The urine extracts (organic and polar phases) were dissolved in 0.55 mL deuterochloroform (with an internal standard, TMS) and ¹H-NMR spectra of the urine samples were recorded using an Avance II spectrometer (Brucker, Billerica, MA, USA) that was operating at a proton frequency of 600.58 MHz. The ¹H-NMR spectra were collected using standard one-dimensional Carr–Purcell–Meiboom–Gill (CPMG) pulse sequence with water presaturation, at 300 K temperature. For each sample, 128–512 consecutive scans (NS) with a 400 μs spin-echo delay were collected; there were 80 loops for the T2 filter, with a 3.5 s relaxation delay and a 2.73 s acquisition time, a time-domain of 64k, and a spectral width of 20.02 ppm. The spectra were processed with a line broadening of 0.3 Hz and were manually phased and baseline corrected using Topspin 1.3 software (Brucker, Billerica, MA, USA). The water spectrum region was removed from the analysis.