DETERMINATION OF NITRITE AS 4-(4-NITROBENZENAZO)-1-AMINONAPHTHALENE DYE USING OPTICAL MEMBRANES BASED ON PVC-DOS MATRIX

Choirul Amri (Environmental Health Department, Health Polytechnics, Jl. Tatabumi, Yogyakarta 55293)
Dwi Siswanta (Chemistry Department, Faculty of Mathematics and Natural Sciences Gadjah Mada University, Yogyakarta 55281)
Mudasir Mudasir (Chemistry Department, Faculty of Mathematics and Natural Sciences Gadjah Mada University, Yogyakarta 55281)

Indonesian Journal of Chemistry
Vol 5, No 3 (2005)

A study of a liquid polymeric membrane based on polyvinylchloride-dioctylsebacate (PVC-DOS) as optical membrane for the spectrophotometric and visual determination of nitrite has been done. The method relied on the formation of a purple colored 4-(4-nitrobenzenazo)-1-aminonaftalen dye in the membrane. The result showed that liquid polymeric membrane can be used as an optical membrane for the determination of nitrite. Optimum conditions of method achieved at a wavelength of 525 nm, reaction pH of 1.7-1.8, and respon time of 45 minutes. This method gave linear range of concentration at 0.0-0.17 mg/L NO2--N, detection limit of 0.004 mg/L NO2--N, and sensitivity of 4.981+0.110 absorbance unit per mg/L of NO2--N. The spectrophotometric and visual optical membrane method by is good for the determination of nitrite at the concentration range of 0.01-0.11 mg/L NO2--N and 0.02-0.60 mg/L NO2--N, respectively.