1. PHOTOMETRIC DETERMINATION OF BIURET IN MELTED UREA USING FLOW INJECTION ANALYSIS. Authors: FRENŢIU TIBERIU, MICHAELA PONTA, EUGEN DARVASI, LADISLAU KÉKEDY-NAGY, IOAN MĂRGINEAN, EMIL A. CORDOŞ.2. FLAME ATOMIC EMISSION DETERMINATION OF POTASSIUM IN NATURAL WATERS WITH THE METHANE-AIR FLAME AS EXCITATION SOURCE. Authors: LADISLAU KÉKEDY-NAGY, EMIL A. CORDOŞ.3. FLAME ATOMIC ABSORPTION DETERMINATION OF ZINC IN NATURAL WATERS USING THE METHANE - AIR FLAME. Authors: LADISLAU KÉKEDY-NAGY, EMIL A. CORDOŞ.4. FLAME ATOMIC EMISSION SPECTROMETRIC DETERMINATION OF BARIUM USING THE METHANE - AIR FLAME. OPTIMIZATION OF THE FLAME AND INSTRUMENTAL PARAMETERS. Authors: LADISLAU KÉKEDY-NAGY, EMIL A. CORDOŞ.5. OPTIMIZATION OF THE FLAME ATOMIC EMISSION DETERMINATION OF MAGNESIUM IN THE METHANE - AIR FLAME. Authors: LADISLAU KÉKEDY-NAGY, EMIL A. CORDOŞ.6. FLAME ATOMIC EMISSION DETERMINATION OF CALCIUM IN NATURAL WATERS USING THE METHANE-AIR FLAME. Authors: LADISLAU KÉKEDY-NAGY, EMIL A. CORDOŞ.