Use of thermal analysis coupled with differential scanning calorimetry, quadrupole mass spectrometry and infrared spectroscopy (TG-DSC-QMS-FTIR) to monitor chemical properties and thermal stability of fulvic and humic acids - Fig 5

<p>FTIR 2D spectra of FA4 (a, c) and HA4 (b, d) for characteristic temperatures of R1, R2 and R3 intervals.</p>