Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1218423 | Journal of Food Composition and Analysis | 2012 | 11 Pages |
Powdered, thawed composited, and fresh frozen fish tissues were analyzed for Hg, Se, As, and Br. Experiments were designed to measure or estimate upper limits of long-term storage, drying, and instrumental neutron activation analysis (INAA) irradiation-related analyte losses. Tissue was analyzed as received (dried, if necessary, for INAA) and treated with l-cysteine to determine if such treatment reduces analyte loss, especially for Hg. Untreated tissues experienced large (23–49%) volatile Hg losses during irradiation. l-Cysteine treatment followed by freeze drying reduced Hg losses to 0.9–3.5%. Desiccation over Mg(ClO4)2 and oven drying at 40 °C of treated tissues were less successful at reducing Hg irradiation loss. Irradiation losses for volatile Se, As, and Br species were smaller, ranging from 0.06–0.4%, <0.01–0.11%, and 0.02–1.0%, respectively. Treated tissue drying losses for Hg, Se, As, and Br ranged from about 3–20%, ≤2–6%, <0.2–6%, and <0.3–3%, respectively, depending on drying method. There was some evidence that, unlike for Hg, l-cysteine treatment enhanced Se drying loss. There was little evidence of element loss during long-term storage at −80 °C, except for an 8% loss from Hg in desiccator dried, l-cysteine treated powdered fish protein.
► Up to half of untreated fish tissue Hg lost as volatile during neutron irradiation. ► l-Cysteine treatment, freeze drying reduced Hg irradiation loss by up to factor of 26. ► l-Cysteine treatment with desiccator or oven drying less effective for Hg retention. ► Se, As, and Br irradiation losses from fish tissues much lower (<0.01–1.0%) than for Hg. ► Up to 20% of Hg, 1% of Se, 6% of As, and 3% of Br lost during drying procedures.