Determination of Formaldehyde using Sensor Formaldehyde Dewi Umaningrum 1 *, Radna Nurmasari 1 , Maria Dewi Astuti 3 , Ani Mulyasuryani 4 , Diah Mardiana 5 1 Department of Chemistry, Faculty of Mathematics and Sciences, University of LambungMangkurat, Banjarmasin, South Kalimantan, Indonesia 2 Department of Chemistry, Faculty of Mathematics and Sciences, University of Brawijaya, Malang, East Java, Indonesia Abstract : Determination of formaldehyde using sensor formaldehyde. The aim of this study was to make SPCE-based formalin sensors using cellulose acetate as ionophore by studying the effect of pH, response time and its application on salted fish samples. The results showed that the formalin sensor gave the optimum measurement results at the pH of the solution at 4 with a response time of 10 seconds. The results of measuring formalin in salted fish using sensors compared to the spectrophotometric method gave results that were not significantly different. Key words : ion selective electrode, formaldehyde sensor, Screen Printed Carbon Electrode (SPCE ). 1. Introduction 1 Formalin is a trade name for formaldehyde solution 36-40%. Addition of formaldehyde to food in addition to having a low price, formalin has the function of eradicating various types of bacteria, one of which is spoilage bacteria so that it can cause food to last longer and last longer 1 ). The impact of excessive use of formalin on the body will cause interference with organs and systems that exist in the human body. Seeing the dangers that can be caused from the use of formaldehyde, the government through the Regulation of the Minister of Health of the Republic of Indonesia No.722 / MenKes / Per / IX / 88 prohibits the addition of formaldehyde to food even though in practice there is still a lot of food circulating in the community and containing harmful formalin 2 . Many methods have developed and are used to perform formal and quantitative analysis of food formalin. Quantitative analysis methods commonly used to determine formalin levels are spectrophotometric methods. The use of this method requires chromotropic acid reagent (1,8-dihydroxynaphthalene-3,6-disulfonic acid). The spectrophotometer-based observation process requires several process steps, including: the stages of formalin separation from food samples, formation of purple dibenzoxantilium cation complex with Dewi Umaningrum et al /International Journal of ChemTech Research, 2019,12(3): 28-32. DOI= http://dx.doi.org/10.20902/IJCTR.2019.120304 International Journal of ChemTech Research CODEN (USA): IJCRGG, ISSN: 0974-4290, ISSN(Online):2455-9555 Vol.12 No.03, pp 28-32, 2019