Development of an Automated Analytical System of Low Cost for High-Throughput Infrared Thermometric Titration
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Thermometric titration is an enthalpimetric technique of analysis that uses the enthalpy variation of a reaction to determine the equivalence point of a titration for quantification of the analyte. One of the advantages of this technique is that it does not require sample preparation, such as digestion; it only needs to weigh the sample and add auxiliary reagents. Based on this technique, the aim of this work was to develop automated equipment for thermometric titration, using a contactless infrared temperature sensor. The equipment was manufactured using the concept of additive manufacturing. A Raspberry Pi microcomputer was used to interpret the signal from the temperature sensor and to control a micropump used to dispense titrant at a rate selected by the user. Components were designed using computer-aided design (CAD) software and printed on a fused deposition material printer. For evaluation of the equipment, tests were performed using neutralization and precipitation reactions, measuring the total acidity of vinegars and sodium in sauces. The temperature of reaction was plotted in an enthalpogram, from which the endpoint could be determined. Values of agreement between the method proposed and the reference method ranged from 100 to 104% for total acidity of vinegars and from 96 to 105% for the determination of sodium in sauce. The equipment proved to be technically feasible and of low cost, given that it used alternative and biodegradable materials such as polylactic acid.
KeywordsThermometric titration Infrared enthalpimetry Direct sodium determination Total acidity
This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—Brasil (CAPES), Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), and Fundação de Amparo à Pesquisa do Estado do Rio Grande do Sul (FAPERGS).
Compliance with Ethical Standards
Conflict of Interest
Iberê Damé Teixeira declares no conflict of interest. Bruna Tischer declares no conflict of interest. Roberta Oliveira Santos declares no conflict of interest. Keiti Oliveira Alessio declares no conflict of interest. Gilson Augusto Helfer declares no conflict of interest. Liane Mahlmann Kipper declares no conflict of interest. Juliano Smanioto Barin declares no conflict of interest. Adilson Ben da Costa declares no conflict of interest.
This article does not contain any studies with human or animal subjects.
Publication has been approved by all individual participants.
- Anastas PT, Warner JC (2000) Green chemistry: theory and practice. Oxford University Press, OxfordGoogle Scholar
- Cunniff P (1995) Official methods of analysis of AOAC International 16th ed AOAC Int. Gaithersburg.Google Scholar
- Smith T, Haider C (2014) Novel method for determination of sodium in foods by thermometric endpoint titrimetry (TET). J Agric Chem Environ 3:20–25Google Scholar
- Tischer B, Teixeira ID, Filoda PF, Alessio KO, Barin JS, Duarte FA, Kipper LM, Helfer GA, Costa AB (2019) Infrared enthalpymetric methods: a new, fast and simple alternative for sodium determination in food sauces. Food chemistry (accepted manuscript (FOODCHEM-D-19-01119).Google Scholar