A new application of pH-dependent/charge transfer-sensitive spectrophotometer: Enhanced selective extraction of trace acrylamide in the selected foods by triplet quenching of Phenosafranine in presence of Sn(IV).

In this study, a new method, based on pH-dependent charge transfer (CT), was developed for the selective extraction of acrylamide (AAm) from the sample matrix prior to its analysis. The method is based on CT-sensitive ion-pair formation among AAm, Phenosafranine (PSF), and Sn(IV) at pH 5.0, and extraction with polyethylene glycol tert-octylphenyl ether (Triton X-114). The ion-pair was enriched, diluted to 0.4 mL with methanol, and monitored at 640 nm by spectrophotometer. The variables affecting extraction efficiency were evaluated and optimized. Under optimal conditions, a recti-linear relationship, being 2.0-fold more sensitive below 10 μg L-1, was obtained in the range of 1-10, 10-180 μg L-1, with limits of detection and quantification (LODs and LOQs) of 0.20 and 0.67 μg L-1. From extraction of 25-mL sample solution, a sensitivity improvement and pre-concentration of 27.3 and 62.5-folds, respectively, were obtained. The recovery rate was in range of 95.2-103.6%, with a lower RSD than 5.5%. After the validation, the method was successfully applied to the analysis of the selected food samples.