PERTANIKA JOURNAL OF TROPICAL AGRICULTURAL SCIENCE

A comparative study of the determination of iron in a wide variety of foods was carried out using the atomic absorption spectrophotometric (AAS) and phenanthroline colorimetric methods. A total of 156 foods, belonging to 8 food groups were studied. For each food (determined in duplicate), ash solution was prepared and an aliquot subjected to AAS analysis, while another aliquot was determined by the phenanthroline method. Mean values for duplicate analysis of each food determined by the two methods were tabulated according to food groups. Results obtained by the AAS and phenanthroline methods showed good general agreement, with a correlation coefficient of 0.987. Statistical analysis using paired t-test showed that for 5 food groups, there was no significant difference (p < 0.05) in results given by the two methods. Although a significant difference was observed for the remaining 3 groups, the t-statistic calculated was just above the significance level. Recovery values given by the two methods were satisfactory, and were not significantly different. Variance for the phenanthroline method was, however, slightly higher. Results of the study suggest that both methods can be used satisfactorily far the analysis of this mineral.