A new procedure for the voltammetric determination of toxic (As, Cd, Pb) and essential (Se, Cu, Zn, Fe) elements in various biologically active food additives (FAs) based on phytopreparations has been developed. Sample preparation includes the acid (HNO3 + H2O2) or UV destruction of interfering substances followed by the reduction of As(V) and Se(VI) to the corresponding electroactive As(III) and Se (IV) forms. The elements Zn, Cd, Pb, and Cu are simultaneously determined using a mercury film electrode; As and Fe are determined sequentially, and Se is analyzed separately using a gold/graphite electrode and an appropriate supporting electrolyte. The content of elements in various analyzed FAs varied in a broad range of concentrations (mg/kg): Zn, 0.3 - 10000; Cd, 0.001 - 0.5; Pb, 0.001 - 0.5; Cu, 0.1 - 200; As, 0.01 - 1.0; Fe, 20 - 2000; and Se, 0.1 - 50. Metrological attestation performed with a large number of samples (above 400) showed a repeatability of 9%, a reproducibility of 13%, and an accuracy of 30%. The proposed analytical procedure is included into the Federal Register of Methods issued by the State Standard Pharmacological Committee of the Russian Federation, which includes methods admitted for use in the field of State Metrological Control and Supervision, and is recommended for use in laboratories of FA producing plants, state sanitary-epidemiological supervision offices, etc.
ASJC Scopus subject areas
- Drug Discovery