Flame atomic absorption spectrometric determination of zinc after colloid precipitate flotation with hydrated iron(III) oxide and iron(III) tetramethylenedithiocarbamate as collectors

Colloid flotation of zinc from fresh water with a combination of two collectors, hydrated iron(III) oxide (Fe2O3 . xH(2)O) and iron(III) tetramethylenedithiocarbamate (Fe(TMDTC)(3)), permits rapid separation of the precipi tate before its atomic absorption spectrometric (AAS) analysis. All important parameters necessary for the successful flotation like optimal mass of collectors, pH of the medium, electrokinetic potential of the collector particle surfaces, type of tenside, induction time etc., were checked. At the optimal pH value of medium (5.5) establishing by recommended procedure, zinc was separated quantitatively (97.4-98.8%) with 5 mg Fe(III) as constitutive element of the two collectors used. The content of zinc was determined by flame atomic absorption spectrometry (FAAS). These results were compared with the results obtained by inductively coupled plasma--atomic emission spectrometry (ICP-AES). The FAAS detection limit for zinc is 9.4 mu g l(-1). The proposed method is simple, rapid and applicable to the zinc separation at mu g l(-1) levels from a large volume of water. (C) 1997 Elsevier Science B.V.