Deep eutectic solvent-based electromembrane hollow fiber liquid phase microextraction for determining Pb in water and food samples

In the present work, the determination of Pb using the electromembrane hollow fiber liquid phase micro -extraction with a deep eutectic solvent and graphite furnace atomic absorption spectrometry detection (DES-EM-HFLPME-GFAAS) was proposed. First, Pb(II) in the sample was converted to the anionic form of Pb-oxyanion under alkali conditions. Then, the electro-assisted technique was applied to facilitate the anion passing through the supported liquid membrane into the phase of deep eutectic solvent mixed with buffer solution. Finally, GFAAS was applied for monitoring the total lead in samples. The important parameters affecting the method efficiency were studied. Under optimized conditions, the linear range was observed in the range 0.036-1.0 ng/mL. The limit of detection and limit of quantitation were 0.011 and 0.036 ng/mL, respectively. Precision as %RSD was obtained from 1.03% to 3.49%. The enrichment factor and the preconcentration factor were 111 and 750, respectively. The proposed method was applied to determine lead in water and food samples (i.e., drinking and tap water, canned food, and vegetables) with acceptable recoveries from 86.70% to 116.0%. The method was successfully applied to determine the amount of lead in the standard reference materials, and the concentrations measured were not significantly different at 95% of confidence level from the certified values.