Simple and Fast Method for Iron Determination in White and Red Wines Using Dispersive Liquid-Liquid Microextraction and Ultraviolet-Visible Spectrophotometry

This work reports the development of a method for Fe extraction in white and red wines using dispersive liquid liquid rnicroextraction (DLLME) and determination by ultraviolet-visible spectrophotometry. For optimization of the DLLME method, the following parameters were evaluated: type and volume of dispersive (1300 mu L, of acetonitrile) and extraction (80 mu L of C2Cl4) solvents, pH (3.0), concentration of ammonium pyrrolidinedithiocarbamate (APDC, 500 mu L of 1% m/v APDC solution), NaCl concentration (not added), and extraction time. The calibration curve was performed using the analyte addition method, and the limit of detection and relative standard deviation were 0.2 mg L-1 and below 7%, respectively. The accuracy was evaluated by comparison of results obtained after Fe determination by graphite furnace atomic absorption spectrometry, with agreement ranging from 94 to 105%. The proposed method was applied for Fe determination in white and red wines with concentrations ranging from 1.3 to 4.7 mg L-1.