ATR-FTIR SPECTROSCOPY AS A RAPID COMPLEMENTARY TOOL FOR QUALITATIVE ASSESSMENT OF MINERAL FERTILIZERS

Abstract

Complementary analytical methods are crucial for the qualitative assessment of mineral fertilizers commonly applied in agriculture. In this study, both reference substances and fertilizer samples were analyzed using the ATR-FTIR technique. Pure compounds such as ammonium sulfate, potassium sulfate, and calcium sulfate heptahydrate were first recorded as standards to establish a reference spectral library. Fertilizer samples were ground to a fine powder (<1 mm) and placed on the diamond crystal surface for spectral measurement. The obtained absorption spectra enabled identification of the main components present in the fertilizers and provided a clear comparison with the standard spectra. Although the method allows only qualitative determination of compounds, comparison with the recorded standards provides valuable insights into the composition of the investigated samples. This approach is particularly useful when rapid screening of fertilizers is required without the need for time-consuming wet chemistry analyses. The results demonstrate that ATR-FTIR spectroscopy can serve as a reliable complementary method for routine fertilizer testing, ensuring both quality control and detection of possible adulteration or impurities. Furthermore, when combined with conventional laboratory techniques such as titrimetry, AAS, or ICP-OES, the method contributes to a more comprehensive and accurate characterization of fertilizer composition, ultimately supporting sustainable agricultural practices.