Method Validation for the Determination of Mercury, Cadmium, Lead, Arsenic, Copper, Iron, and Zinc in Fish Through Microwave-Induced Plasma Optical Emission Spectrometry (MIP OES)

A simple, sensitive, and selective analytical method was validated for the determination of mercury, cadmium, lead, arsenic, copper, iron, and zinc in fish muscle using microwave-induced plasma optical emission spectrometry (MIP OES) after acid digestion. The procedure for determining linear range, detection and quantification limits, selectivity, trueness, repeatability, reproducibility, and uncertainty of the method is reported. The results of the validation process demonstrate that the method complies with the provisions of the European Commission guidelines for metals mercury, arsenic, copper, iron, and zinc, but for cadmium and lead, it can only be used as a screening method. The SRM 1946 (Lake Superior Fish Tissue) certified reference material was used to evaluate analytical result quality. The recovery varies between 87 and 99.7%. The HorRat value was equal to or lower than 0.67, and the expanded uncertainty was lower than 37%. The method described can be considered adequate for the simultaneous determination and quantification of the chosen heavy metals in fish matrices. For Cd and Pb, the method could only be employed as a screening tool and not for official control of these contaminants.