[1] Tech Univ Cluj Napoca, Fac Sci, 76 Victoriei St, Baia Mare 430122, Romania
[2] Res Inst Analyt Instrumentat, INCDO INOE 2000, 67 Donath St, Cluj Napoca 400293, Romania
[3] Babes Bolyai Univ, Fac Phys, 1 Kogalniceanu St, Cluj Napoca 400084, Romania
[4] Babes Bolyai Univ, Fac Chem & Chem Engn, 11 Arany Janos St, Cluj Napoca 400028, Romania