PENGEMBANGAN SENSOR FORMALIN PADA MAKANAN BERBASIS IMMOBILISASI PARAROSANILIN DENGAN TEKNIK SOL-GEL

Abstract

Formalin is one of the dangerous preservative usually mixed into the food now. Formalin has a dangerous effect for human body and forbidden to use as food preservative. The purpose of this study was to construct the device that can detect formalin in food rapidly. This device is chemical sensor that contain pararosaniline reagent Pararosaniline reagent immobilized with sol-gel technique with tetra methyl ortho silicate (TMOS) as a precursor. Pararosaniline that immobilized in sol-gel matrix will be react with formalin in solution that diffuse into the membrane pore and produce the complex compound that have purple colour. The absorbances of the membrane were assayed spectrophotometrically The pararosaniline sol-gel membrane performance including the limit of detection, the limit of quantitation, sensitivity, selectivity, reproducibility were 90 ppm, 300 ppm, 0,05 absorbance / 100 ppm, salt as the main interefence in food analysis, and RSD 1-4 %. Based on this analytical characteristics, it has been show that membrane can used for analysis of formalin, because of it’s simple use, rapid analysis and efficient with good accuracy. The membrane response were 10 minute, optimal pH in pH 3. This membrane can use for pre detection with qualitative result. The membrane use is a single use only (disposable) because the membrane support is plastic that can not regenerated with strong acid.