The results obtained from these preliminary studies indicate the potential use of guava leaf extract as an alternative reagent for quantification of iron in samples with simple matrices. The detection limit may possibly be improved by increasing the concentration of the guava leaf extract.No samp letreatment I sneeded for iron concentrations at orbelow 30ppm since Fe (III) and Fe (II) absorbances are similar, probably due to complete reduction of the Fe (III) by some chemicals naturally present in the guava leaves. Higher concentrations might be measured by adding a reducing agent such as hydroxylamine to convert the Fe (III) to Fe (II). Further studies are needed. Prior to applying the guava leaf extract in studies of samples containing complicated matrices, further studies should be Fig. 4. Characteristics of the signals obtained from the reverse FIA system. made.