| dc.description.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. | en_US |
