Lead determination in canned food by square-wave adsorptive cathodic stripping voltammetry

Abstract

A sensitive and rapid method to analyse Pb(II) in canned fish samples was developed using square-wave adsorptive cathodic stripping voltammetry based on the adsorptive accumulation of 8-hydroxyquinoline complexes of Pb(II) onto a hanging mercury drop electrode, followed by reduction of adsorbed species by voltammetric scan with square wave pulse modulation. The optimum conditions were found to be 0.1 M CH 3 COONH 4 as a supporting electrolyte, pH 7.5, 8-hydroxyquinoline concentration of 15 µM, accumulation potential −0.70 V (versus Ag/AgCl), accumulation time 120 s, scan rate 0.3 V/s, and pulse amplitude 20 mV. Under the optimum conditions a linear calibration graph was obtained in the concentration range of 0.5-90.0 µg/l with correlation coefficient 0.9973, a limit of detection of 0.108 µg/l, and a limit of quantification of 0.360 µg/l. The recovery values were obtained in the range 93.7-95.1%. The relative standard deviations (n = 10) at lead concentration 5.0 µg/l was 2%. The method was successfully applied to the determination of lead content in canned fish samples. The concentration of Pb(II) in canned fish samples (wet weight) was found to be in the range of 0.121-0.285 µg/g, which is lower than the limit (1.00 µg/g) issued by the Ministry of Public Health of Thailand.

Complexation-Based Detection of Nickel(II) at a Graphene-Chelate Probe in the Presence of Cobalt and Zinc by Adsorptive Stripping Voltammetry

“…The use of stripping analysis has significantly increased over the last two decades and has proved to be a highly sensitive method for the ultra-trace determination of metal ions. The simplicity and rapidness of the electrochemical analytical techniques, ability for in-situ pre-concentration steps [ 6 , 7 ] and low cost and reliable nature [ 8 ] makes it an attractive alternative to the more common chromatographic and atomic absorption spectrometric methods. Anodic stripping voltammetry (ASV), cathodic stripping voltammetry (CSV) and adsorptive stripping voltammetry (AdSV) are three common examples of conventional stripping methods.…”