Determination of Urea and Humate in Humate Fertilizers Using ATR FTIR Spectroscopy

Conditions for the simultaneous determination of urea and humate concentrations in aqueous fertilizers using attenuated total reflection Fourier transform (ATR FTIR) spectroscopy were proposed. The spectra of urea and humate were identified. The characteristic absorption bands of urea and humate were selected for their simultaneous determination. Errors in the determinations of urea and humate were minimal when analytical signals were measured at 1628 and 1598 cm–1 (10−200 g/L) and 1380 cm–1 (10−100 g/L), respectively. When the humate and urea contents of their mixtures were calculated using Vierordt’s method, the error in determining each component was 3%. The determination conditions proposed were tested using model fertilizers and commercial humate fertilizers.