Exploiting guava leaf extract as an alternative natural reagent for flow injection determination of iron

Flow Injection Determination of Iron Ions with Green Tea Extracts as a Natural Chromogenic Reagent

“…Second, diluted HCl pH 4.8 was tested, as this pH was reported to be suitable for Fe(III)-polyphenol complex formation. 5 Third, acetate buffer pH 4.8 was also tested and results were compared with those of diluted HCl to investigate if it was necessary to maintain the pH of the solution with a buffer. Both Fe(II) and Fe(III) concentrations of 10 and 100 ppm were used.…”

“…We have performed the study on the reducing effect of green tea extract, using 1,10-phenanthroline to test for the color complex formation of Fe(III) before and after mixing with the extract, similarly to what was described in the same study with guava extract. 5 It was found that both guava and green tea extracts have reducing power to convert Fe(III) to Fe(II). However, at this stage, finding the exact mechanisms of the formation of complexes between iron and the green tea extract have not been further attempted.…”

“…As compared to the fresh guava leaves extract, 5 green tea extract prepared from commercial dry leaves could be a better alternative source of reagent because it can be found in a convenient store and its availability does not depend on season. The combination of natural reagents, which are easily available, with a low cost FI system should provide both environmental and economical benefits.…”

“…4 The semiautomatic features of the flow injection (FI) system, where an analyte to be determined goes through the system in exactly the same conditions (flow rate/detection time/mixing degree) as that of the standard, allow the use of natural reagents that are not necessarily pure. 2,5 In addition, the sample throughputs can be significantly improved. 6 Some examples of natural reagents employed with FI-system have been reported.…”

“…Guava leaf extract was used for determination of iron in water samples with a simple FI system. 5 Plant extracts have also been used as enzymatic sources. Polyphenol peroxidase found in sweet potato root was ultilized in FI-spectrophotometric determination of sulfite.…”