Potentiometric stripping analysis of bismuth based on carbon paste electrode modified with cryptand (2.2.1) and multiwalled carbon nanotubes

摘要: Abstract An electrochemical method based on potentiometric stripping analysis (PSA) employing a cryptand [2.2.1] (CRY) and carbon nanotube (CNT) modified paste electrode (CRY–CNT-PE) has been proposed for the subnanomolar determination of bismuth. The characterization surface carried out by means scanning electron microscopy (SEM), cyclic voltammetry (CV), impedance spectroscopy (EIS) chronocoulometry (CC). It was observed that CRY–CNT-PE, 9-fold enhancement in PSA signal (dt/dE) as compared to plain (PCPE). Under optimized conditions, dt/dE (s/V) proportional Bi(III) concentration range 5.55 × 10−8 9.79 × 10−11 M (r = 0.9990) with detection limit (S/N = 3) 3.17 × 10−11 M. practical analytical utilities were demonstrated bismuth pharmaceutical formulations, human hair, sea water, urine blood serum samples. prepared showed several advantages, such simple preparation method, high sensitivity, very low limits excellent reproducibility. Moreover, results obtained commercial real samples using CRY–CNT-PE those atomic absorption (AAS) are agreement at 95% confidence level.