On-line determination of iron(II) and iron(III) using a spectrophotometric sequential injection system

New method for simultaneous determination of Fe(II) and Fe(III) in water using flow injection technique

“…The most common analytical method applied to Fe speciation is UV/Vis spectrophotometry [1][2][3][4][5][6][7][8][9][10][11]; however, examples of application of other techniques, e.g. differential pulse anodic stripping voltammetry [12], amperometry and differential pulse polarography [13,14], ICP [15], AAS [16,17] as well as combination of spectrophotometry and AAS [18,19] were also reported.…”

“…In particular, Fe(III) and total iron are proposed to be determined before and after oxidization of Fe(II) to Fe(III). The reagent used for this purpose is usually tiron [1,2]. The ammonium thiocyanate reagent was used in ingenious systems with solid-phase extraction module incorporated [4] and with optrode coupled to multi-syringe flow injection system with anionexchanged disk [5].…”

Electrochemical technique to measure Fe(II) and Fe(III) concentrations simultaneously

“…Due to these complexities, researchers are working on modified methods [12]. Pozdniakova et al [13] applied the capillary zone electrophoresis (CZE) method to determine the concentrations of Fe(II) and Fe(III) simultaneously using 1,10-phenanthroline and EDTA, which selectively form complexes with Fe(II) and Fe(III) ions, respectively. The detection limits (DL) are 1.0 9 10 -6 M for Fe(II) and 2.0 9 10 -6 M for Fe(III).…”

Flow-Injection Spectrophotometric Analysis of Iron (II), Iron (III) and Total Iron

“…The spectrophotometric detector based on measuring the absorbance of colored complexes formed with various chromogenic reagents is one of the most frequently used detectors for the determination of iron in many kinds of samples (Yegorov et al, 1993;Yamamura and Sikes, 1966;Ampan et al, 2002;Bruno et al, 2002;Tesfaldet et al, 2004;Van Staden and Kluever, 1998;Mulaudzi et al, 2002;Pojanagaron et al, 2002;Araujo et al, 1997;Udnan et al, 2004;Alonso et al, 1989;M¨uller et al, 1990;Themelis et al, 2001;Kass and Ivaska, 2002;Weeks and Bruland, 2002). A large number of flow-injection spectrophotometric methods have been developed for the determination of iron using desferal (Yegorov et al, 1993), 1,10-phenantroline (Yamamura and Sikes, 1966;Ampan et al, 2002;Bruno et al, 2002;Tesfaldet et al, 2004), tiron (Van Staden and Kluever, 1998;Mulaudzi et al, 2002), ferrozine , norfloxaxin (Pojanagaron et al, 2002), thiocyanate (Araujo et al, 1997), DMF , and salicylate (Udnan et al, 2004) as chromogenic reagents. However, many of the proposed methods have a high limit of detection (Alonso et al, 1989;M¨uller et al, 1990), suffer from many interfering metal ions, such as Zn and Co (Guo and Baasner, 1993), have a short linear dynamic range (Themelis et al, 2001;Kass and Ivaska, 2002), tedious procedures (Pons et al, 2005b), or low sampling rates (Teixeira and Rocha, 2007;Lunvongsa et al, 2006a).…”