Acta Facultatis Ecologiae - Technická univerzita vo Zvolene

46deposit is that stripped in off-line system to the graphitecuvette of the electrothermal atomizer.On-line coupling FTC and GFAASOn-line takes advance of coupling of two stepsto one’s. At the first step, analyte is deposited onworking electrode from flowing sample. At the secondstep, the analyte is then quantitatively determinedby the suitable analytical method.The main topic of the preconcentration step is tomaximize the concentration of the analyte with the simultaneouslysuppressing the effect of interference.MATERIALS AND METHODSGFAASThe AAS spectrometer Spectraa 400 with thegraphite furnace atomizer (Varian) was used tomeasure the preconcentrated Sb species.FTCThe flow-through electrochemical analyzerEcaFlow (model GLP 150, Istran, Bratislava) wasused as the preconcentration unit with a two-electrodecell. The working electrode was a RVC electrodecoated with gold (Fig. 1).Scheme of the on-line couplingFTC-GFAASThe 6-way valve was connected with samplingloop with sampling volume 83.9 µl. Thereby onlineconnection of electrochemical analyzer Eca-Flow could by make by coupling with GFAASover the 6-way valve (Fig. 2).Fig. 1 Scheme of the flow-through cell with dual electrode connectionLegend: 1 – working electrode E-53 Au, 2 – inert inset, 3 – auxilliary Pt electrode, 4 – plexi glass body,5 – packing, 6 – screwFig. 2 Scheme of the flow–through system FTC-GFAASLegend: 1 – pump, 2 – valve, 3 – preconcentration cell, 4–6-way valve with sampling loop calibrated to thesampling volume 83.9 µl