Sonochemical Synthesized Manganese Oxide Nanoparticles as Fluorescent Sensor for Selenium (IV) Quantification. Application to Food and Drink Samples.

Manganese oxide nanoparticles (MnO Nps), sonochemical synthesized and characterized in our laboratory, are proposed as fluorescent sensor for selenium (Se) determination. The new methodology has been developed based on the enhancing effect of the Se(IV) on fluorescent emission of MnO Nps. Experimental variables that influence on fluorimetric sensitivity were optimized. The calibration graph using zero order regression was linear from 0.189 ng L to 8.00 × 10 µg L, with correlation coefficient better than 0.99. Under the optimal conditions, the limits of detection and quantification were of 0.062 ng L and 0.189 ng L, respectively. The trueness of the methodology was assessed through standard addition method obtaining recovery near to 100%. This method showed good tolerance to foreign ions, particularly to Se(VI), and was applied to determination of Se(IV) trace in food and drink samples with satisfactory results. With the intention of preserving the environment from harmful effects, a degradation study of the used nanomaterials has been included for their subsequent disposal.