Quantification of lead and cadmium in poultry and bird game meat by square-wave anodic-stripping voltammetry

Abstract

A square-wave anodic-stripping voltammetric method for the analysis of lead and cadmium in chicken muscle and liver was developed and validated, and the results of a monitoring study relative to chicken and pigeon meat are reported. The voltammetric method allows the analysis of lead and cadmium at the same time in samples after acid digestion. The use of perchloric acid for digestion and of acetate buffer in the supporting electrolyte are suitable to reduce matrix interferences and obtain limits of quantification which were below 10 ng g⁻¹ for meat and liver samples. The regression between the analytical signal and the concentration of the target analytes in spiked samples and Certified Reference Materials proved to be linear within the 10–100 ng g⁻¹ range for meat and within the 50–500 ng g⁻¹ range for liver. The analytical method was verified using available Certified Reference Materials BCR-184 (cattle meat) and BCR-185R (cattle liver) as well as with spiked chicken samples. Precision (i.e. repeatability and intermediate precision) and accuracy (percentage recovery and bias) were of the order of 0.3–4.5% for both lead and cadmium The level of lead in muscle was in the range between 6.4 and 59.8 ng g⁻¹ in chickens and between 7.9 and 63.6 ng g⁻¹ in farmed pigeons, whereas it was between 8.0 and 84.4 ng g⁻¹ in chicken liver. The cadmium concentration was 0.4–10.4 ng g⁻¹ in chicken muscle, 10.4–90.6 ng g⁻¹ in chicken liver and 2.2–8.0 ng g⁻¹ in farmed pigeons.

Keywords:

• quality assurance
• metals analysis
• stripping voltammetry
• heavy metals
• lead
• cadmium
• meat
• animal products