Affiliation: Department of Analytical Chemistry, University of Valencia, 50 th Dr. Moliner St., E-46100 Burjassot, Valencia, Spain.
In the present study, two analytical methodologies, one based on direct thermal degradation of samples followed by atomic absorption analysis (TDA-AAS), and another one, which consists on acid microwave-assisted digestion (MAD) followed by cold vapour atomic fluorescence determination (CV-AFS), have been applied to determine mercury in mushrooms. Both methodologies found the same concentration values, from 258 to 570 ng g-1 (dry weight), for nine samples. Analysis based on thermal degradation provided a limit of detection of 3 ng g-1 similar to that found by CV-AFS, and a relative standard deviation of 3 %, three times higher than that of CV-AFS. However, the direct analysis of untreated samples agrees well with green analytical principles because it involves less reagents consume and reduces waste generation. In fact, at analytical Eco-Scale, TDA-AAS procedure involves a green score of 92 points in front of the 59 points obtained for CV-AFS method.