Programa de Pós-graduação em Sistemas e Processos Industriais, Universidade de Santa Cruz do Sul, 96815-900 Santa Cruz do Sul, RS, Brazil; Programa de Pós-Graduação em Tecnologia Ambiental, Universidade de Santa Cruz do Sul, 96815-900 Santa Cruz do Sul, RS, Brazil. Electronic address: [Email]
This work developed a new technique and an application of an existing approach to determine sodium in food sauces, involving enthalpimetric reactions in the infrared. Infrared Thermometric Titration (TT-IR) was utilized, with simple analyzers and low-cost measurement instruments for the acquisition of the surface temperature generated in the sodium precipitation reaction and development of software for the acquisition and processing of data using Raspberry Pi. The sodium was also quantified by Thermal Infrared Enthalpimetry (TIE), a recently developed technique. The rapid and simple quantification of sodium by the TT-IR and TIE showed the possibility of a selective reaction for sodium, using aluminum nitrate, potassium and ammonium fluoride in an acid medium, with reduction of the reagents and without the digestion step in the sample preparation. The results acquired through TT-IR and TIE corroborated the Flame Atomic Emission Spectrometry (FAES) with 96 to 103% and 95 to 102%, respectively.