Validación de un método de espectroscopia de absorción atómica con vapor frio e inyección de flujo para la medición de mercurio total en productos de la pesca.

Introduction: mercury (Hg) accumulates in large predatory species in marine ecosystems, such as tuna, swordfish, or various sharks species. Objective: to validate, through additions, a method of atomic absorption spectroscopy with cold vapour and flow injection system for the measurement of total Hg in seafood products. Material and methods: a total of 18 samples of different seafood products were analysed, spiking them to 4 ranges: low (0.1 mg/ kg); intermediate (0.5 and 1.0 mg/kg) and high (2.0 mg/kg). These were digested in a microwave oven and analysed with an atomic absorption spectrometer. Results: the diversity of the samples and the good accuracy and precision of the results confirmed the selectivity of the method. The working range of the method was established between 0.10-0.32 mg/kg of Hg in the sample and the limit of quantification at 0.10 mg/kg. All calibration lines fitted the linear regression model with statistical significance (p < 0.05). The trueness was 4.28%; 3.20 %; 12.28 % and 0.84% respectively for the 0.1 mg/kg; 0.5 mg/kg; 1.0 mg/kg and 2.0 mg/kg ranges, respectively. The average recovery of the method was 102.54 %. Horrat reproducibility (HorratR) values were 0.41; 0.30; 0.37 and 0.66 and Horrat repeatability (Horratr) values were 0.48; 0.35; 0.11 and 0.47 for the 0.1 mg/kg; 0.5 mg/kg; 1.0 mg/kg and 2.0 mg/kg spiking ranges, respectively in each case. The relative uncertainty values in each range were lower than the fixed limit of 25 %. Conclusion: our method was validated by fulfilling the regulatory requirements and the previously established acceptance criteria. [ABSTRACT FROM AUTHOR]