Measurement of haem and total iron in fish, shrimp and prawn using ICP-MS: Implications for dietary iron intake calculations.

Twenty-five species of fish, shrimp and prawn from local markets in Bangladesh were analysed for concentrations of total Fe, haem Fe and non-haem Fe by ICP-MS. Total Fe and non-haem Fe concentrations were measured in nitric acid-digested samples and haem Fe was extracted using acidified 80% acetone for 60 min. Total Fe concentrations ranged from 0.55-14.43 mg/100 g FW, and haem Fe% ranged from 18%-93% of total Fe. Repeat extractions with 80% acetone recovered additional haem Fe, suggesting that previous measurement by this technique may have underestimated haem Fe content. Calculation of Fe balance (summing Fe in acetone extracts and Fe in the residue after haem Fe extraction) was not significantly different from total Fe, indicating the two processes recovered the different forms of Fe with similar effectiveness.

Reversed-phase liquid chromatographic determination of phytometallophores from Strategy II Fe-uptake species by 9-fluorenylmethyl chloroformate fluorescence.

An HPLC method to quantitate phytometallophores (phytosiderophores) exuded from roots of barley (Hordeum vulgare L.) growing in nutrient solution culture was developed. 9-Fluorenylmethyl chloroformate (FMOC) derivatives of phytometallophores were separated on a C18 reverse-phase column using a sodium acetate (pH 7.2) and acetonitrile-methanol gradient over 20 min followed by fluorescence detection. Detection limits ranged from 15 to 370 pmol depending on the particular phytometallophore. The effectiveness of this method was demonstrated using the response of barley seedlings to Fe-sufficient and Fe-deficient nutrient solution conditions. Phytometallophores collected in root washings of Fe-deficient barley seedlings increased with plant age while phytometallophore release from Fe-adequate roots was negligible.