Method development for the control determination of mercury in seafood by solid-sampling thermal decomposition amalgamation atomic absorption spectrometry (TDA AAS)

• Published in: Food additives & contaminants. Part A, Chemistry, analysis, control, exposure & risk assessment Vol. 29; no. 4; pp. 625 - 632
• Main Authors: Torres, D.P, Martins-Teixeira, M.B, Silva, E.F, Queiroz, H.M
• Format: Journal Article
• Language: English
• Published: England Taylor & Francis Group 01-04-2012; Taylor & Francis Ltd
• Subjects: ALIMENTO; ALIMENTOS DE ORIGEN MARINO; Animals; ANÁLISE QUÍMICA; Aqueous solutions; CARNE; CHEMICAL COMPOSITION; COMPOSICIA³N QUIMICA; COMPOSITION CHIMIQUE; CONTAMINACIA³N; CONTAMINATION; CONTAMINAÇÃO; environmental contaminants; Fish; fish and fish products; FISH PRODUCTS; Fishes; Food Contamination - analysis; Food Contamination - statistics & numerical data; HEAVY METALS; heavy metals - mercury; http://www.fao.org/aos/agrovoc#c_1794; http://www.fao.org/aos/agrovoc#c_2223; http://www.fao.org/aos/agrovoc#c_28317; http://www.fao.org/aos/agrovoc#c_2930; http://www.fao.org/aos/agrovoc#c_4253; http://www.fao.org/aos/agrovoc#c_4669; http://www.fao.org/aos/agrovoc#c_6905; http://www.fao.org/aos/agrovoc#c_7377; LA©GISLATION; LEGISLACIA³N; LEGISLATION; LEGISLAÇÃO; Limit of Detection; MAR; MA©TAL LOURD; MA©THODE STATISTIQUE; MA©TODOS ESTADA­STICOS; MEAT; Mercury; Mercury - analysis; Mercury - standards; metal determination - AAS; METAL PESADO; METALES PESADOS; method validation; MÉTODO ESTATÍSTICO; PEIXE; PRODUCTOS DERIVADOS DEL PESCADO; PRODUIT AA BASE DE POISSON; PRODUIT ALIMENTAIRE ORIGINE MARINE; PRODUTO DERIVADO DE PESCADO; quality assurance; Reference Standards; seafood; Seafood - analysis; SEAFOODS; Spectrophotometry, Atomic - methods; Spectrophotometry, Atomic - standards; Spectrum analysis; statistical analysis; STATISTICAL METHODS; Tissues; trace elements (toxic); VIANDE
• ISSN: 1944-0049; 1944-0057
• DOI: 10.1080/19440049.2011.642310

A very simple and rapid method for the determination of total mercury in fish samples using the Direct Mercury Analyser DMA-80 was developed. In this system, a previously weighted portion of fresh fish is combusted and the released mercury is selectively trapped in a gold amalgamator. Upon heating, mercury is desorbed from the amalgamator, an atomic absorption measurement is performed and the mercury concentration is calculated. Some experimental parameters have been studied and optimised. In this study the sample mass was about 100.0 mg. The relative standard deviation was lower than 8.0% for all measurements of solid samples. Two calibration curves against aqueous standard solutions were prepared through the low linear range from 2.5 to 20.0 ng of Hg, and the high linear range from 25.0 to 200.0 ng of Hg, for which a correlation coefficient better than 0.997 was achieved, as well as a normal distribution of the residuals. Mercury reference solutions were prepared in 5.0% v/v nitric acid medium. Lyophilised fish tissues were also analysed; however, the additional procedure had no advantage over the direct analysis of the fresh fish, and additionally increased the total analytical process time. A fish tissue reference material, IAEA-407, was analysed and the mercury concentration was in agreement with the certified value, according to the t-test at a 95% confidence level. The limit of quantification (LOQ), based on a mercury-free sample, was 3.0 µg kg
−1
. This LOQ is in accordance with performance criteria required by the Commission Regulation No. 333/2007. Simplicity and high efficiency, without the need for any sample preparation procedure, are some of the qualities of the proposed method.