The influence of NaCl and Na2SO4 as supporting electrolyte on analysis of lead (II) in seawater by stripping voltammetry using hanging mercury drop electrode

Abstract

The influence of NaCl and Na2SO4 as supporting electrolyte on lead (II) analysis in seawater by stripping voltammetry was studied. The instrumental parameters obtained in this recent study were deposition potential -1000 mV, deposition time 150 s, and stirring rate 2000 rpm. The concentration of supporting electrolyte used was 300 µg/L NaCl and 1800 µg/L Na2SO4. The detection limit and sensitivity of the method using NaCl as supporting electrolyte were 0.1483 µg/L and 29.207 nA L/µg, respectively. The precision in the range of 1-5 µg/L of lead (II) was 1.01-6.37%. Lead (II) analysis voltammetrically using Na2SO4 as supporting electrolyte resulted in the analytical performance as follow: detection limit of 0.5498 µg/L, sensitivity of 8.037 nA L/µg, precision of 0.34-5.9 %. Analysis of lead (II) by stripping voltammetry using NaCl and Na2SO4 as supporting electrolyte resulted in recovery of 99.90 % (n=3) and 104.2 % (n=3), respectively. The presence of both NaCl and Na2SO4 slightly amplified the lead (II) current signal. ________________________________________GRAPHICAL ABSTRACT