Development of a flotation method for preconcentration-separation of trace amounts of some metal ions in plant tissues prior to their FAAS determinations

Abstract

Recebido em 29/5/09; aceito em 30/7/09; publicado na web em 11/1/10 An efficient flotation method based on the combination of flame atomic absorption spectrometry (FAAS) and separation and preconcentration step for determination of Cr , Fe 3+ and Pb 2+ ions in various real samples by the possibility of applying bis(2-hydroxyacetophenone)-1,4-butanediimine (BHABDI) as a new collector was studied. The influence of pH, amount of BHABDI as collector, sample matrix, type and amount of eluting agent, type and amount of surfactant as floating agent, ionic strength and air flow rates i.e. variables affecting the efficiency of the extraction system was evaluated. It is ascertained that metal ions such as iron can be separated simultaneously from matrix in the presence of 0.012 mM ligand, 0.025% (w/v) of CTAB to a test sample of 750 mL at pH 6.5. These ions can be eluted quantitatively with 6 mL of 1.0 mol L -1 HNO 3 in methanol which lead to the enrichment factor of 125. The detection limits for analyte ions were in the range of 1.3-2.4 ng mL -1. The method has been successfully applied for determination of trace amounts of ions in various real samples.

Old and New Flavors of Flame (Furnace) Atomic Absorption Spectrometry

“…Finally, the precipitate is collected and dissolved in a small volume and further determined. This method was applied by Ghaedi et al [211] for preconcentration of several elements (Cd, Co, Cr, Cu, Fe, Ni, Pb, and Zn) in digestates of plant materials with LODs in the range of 1.3 to 2.4 ng/mL.…”

Membrane Filtration of Lead, Cobalt, and Nickel in Water and Fertilizer Samples for Enrichment/Separation and Flame Atomic Absorption Spectrometric Determination

“…The negative or positive effects of the main components of real samples on the analyte signals for the spectroscopic determination are called "Matrix Effects" (49)(50)(51)(52)(53). Therefore, sample pretreatment is required prior to analysis to reduce matrix effects.…”

Combination of flotation and flame atomic absorption spectrometry for determination, preconcentration and separation of trace amounts of metal ions in biological samples

“…[13][14][15][16][17][18][19][20] Among the various applicable procedures for separation and preconcentration, including filtration or centrifugation, inconveniences such as lengthy separation, time consumption for high sample volume, multi-stage, lower enrichment factor and consumption of organic harmful solvents can be overcome by the replacement of flotation. [17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35][36] Flotation/preconcentration method with unique advantages such as rapidity and excellent recoveries as well as simple and inexpensive equipments is able to analyze and enrich analyte from large volumes of sample solution to small amount of eluent to obtain a greater preconcentration factor compared with conventional carrier precipitation technique. In this technique, a small amount of surfactant and tiny air bubbles are required to perform a proper flotation procedure to prevent serious contamination risks, which could be manifested by the high blank value.…”

“…13–20 Among the various applicable procedures for separation and preconcentration, including filtration or centrifugation, inconveniences such as lengthy separation, time consumption for high sample volume, multi-stage, lower enrichment factor and consumption of organic harmful solvents can be overcome by the replacement of flotation. 17–36…”