Abstract
Multiwalled carbon nanotubes (MWCNTs) have been functionalized as glycerol plasticized-starch/citric acid (GPS-CA@MWCNTs) and used as a new potent sorbent for lead (Pb) extraction prior to its quantification by flame atomic absorption spectrometry (FAAS). Relevant experimental parameters were optimized prior to the validation and application of the developed extraction technique. It was observed that under optimal conditions, GPS-CA@MWCNTs expressed excellent stability even after more than 100 adsorption/desorption cycles performed with 97% analyte recoveries. The predicted method detection limit and method quantitation limit were estimated to be 0.0325 and 0.0975 µg L
−1
, respectively. The validation of the developed procedure has been carried out via certified reference materials analysis (TMDA-54.4 fortified lake water) and confirmed its precision (relative standard deviations less than 20%) and accuracy (relative error less 11%) under day-to-day conditions. The uncertainty has been estimated via "bottom-up" approach for the extraction of Pb.