A very sensitive flow-injection spectrophotometric determination method for iron (II) and total iron using 2', 3, 4', 5, 7-pentahydroxyflavone.

In this study, an ultra-sensitive and highly selective, rapid flow-injection spectrophotometric method for the determination of iron (II) and total iron has been proposed. The method was based on the reaction between iron (II) and 2', 3, 4', 5, 7-pentahydroxyflavone in slightly acidic solution with a strong absorption at 415 nm. The carrier solution used was 1 × 10(-5) M 2', 3, 4', 5, 7-pentahydroxyflavone in 0.1 M HAc/Ac(-) buffer solution at pH 4.5. Parameters that affect simultaneously the determination of iron (II) and interfering ions were tested. The relative standard deviation for the determination of 50 µg L(-1) iron (II) was 0.85 % (n = 10), and the limit of detection (blank signal plus three times the standard deviation of the blank) was 3 µg L(-1), both based on injection volumes of 20 µL. The method has been successfully applied to the determination of iron (II) and total iron in water samples and ore samples. The method was verified by analysing a certified reference material Zn/Al/Cu 43XZ3F.

Evaluation of metal concentration and antioxidant activity of three edible mushrooms from Mugla, Turkey.

This study is designed for the determination of metal concentrations, antioxidant activity potentials and total phenolics of Amanita caesarea, Clitocybe geotropa and Leucoagaricus pudicus. Concentrations of four heavy metals (Pb, Cd, Cr, Ni) and five minor elements (Zn, Fe, Mn, Cu, Co) are determined. In the case of A. caesarea, Cr and Ni concentrations are found in a high level. Concentrations of the metals are found to be within safe limits for C. geotropa. In beta-carotene/linoleic acid test, L. pudicus showed the highest activity potential. In DPPH system, A. caesarea showed 79.4% scavenging ability. Additionally, reducing power and chelating capacity of the mushrooms increased with concentration. The strongest super-oxide anion scavenger was A. caesarea. In the case of total phenolics, L. pudicus found to have the highest content.