Determination of Lead in Ice by Stripping Potentiometry

Abstract

In order to determine the amounts of lead in ice by stripping potentiometry, the 400 ml matrix modifying solution was added to an ice sample of total volume 30 ml in an electrochemical cell. The modified solution was 800.00 mg/l Hg(II) in 1.30 M hydrochloric acid. The working electrode was a glassy carbon disc, with Ag/AgCl as a reference electrode, and a platinum rod as a counter electrode. Stripping potentiometry was used on sample solutions and standard solutions which were electrolyzed for 3 min at −1.00 V. The peak potentials were set around −0.38 to −0.42 V. The concentrations of lead (II) standards were 0.10, 0.40, 0.70 and 1.00 mg/l. The calibration plot between peak areas and concentration of lead (II) standards was obtained with a correlation coefficient of 0.9969. A detection limit of 0.023 mg/l or 23.00 ng/l (3SD) was shown with a precision of 5.50 % RSD for a 2.0 mg/l standard (n = 5). The percentage recovery was found to be 95.50 %. The concentration range of lead (II) in ice samples was determined to be 0.09 to 0.53 mg/l.

Keywords

• Lead
• ice
• stripping potentiometry
• mercury film