Dithizone functionalized carbon nanofibers as novel nanomaterial for microextraction and determination of mercury in non-alcoholic beverages

Abstract

In this work, a new nanomaterial obtained by surface functionalization of carbon nanofibers with dithizone (CNF@DTZ) was implemented as adsorbent in the dispersive micro-solid phase extraction technique. Preconcentration and determination of Hg in non-alcoholic beverage samples including fruit juices and drinking water were performed with the proposed method. Important parameters of the extraction and back-extraction steps were optimized. Using 3 mg CNF@DTZ only, an extraction efficiency of 98.0 % was achieved for 30 mL of sample. Quantitative back-extraction was achieved with 600 µL of 12 mol/L HCl. A sensitivity enhancement factor of 50 was obtained. The calibration curve was linear in the range from 0.23 to 4.0 µg/L, the LOD was 0.07 µg/L and the RSD% was 3.5 % (2 µg/L Hg, n = 10). This methodology was successfully applied on spiked samples with recoveries from 96.0 to 100 %. This work reports the first application of CNF@DTZ in the dispersive micro-solid phase extraction technique for trace Hg determination in non-alcoholic beverages.