Spectrophotometric determination of EDTA in aqueous solution through ferroin formation using sodium sulfite as the reducer

Ferrous iron oxidation by molecular oxygen under acidic conditions: The effect of citrate, EDTA and fulvic acid

“…Phenanthroline was employed in preference to the commonly employed Fe(II) colorimetric agent ferrozine since, at low pH, ferrozine can induce the reduction of Fe(III) and therefore interfere with the reliable measurement of Fe(II) (Anastacio et al, 2008). Furthermore, phenanthroline can be used to quantify the concentration of Fe(II) in the presence of EDTA and citrate, with no interference due to complex formation (Wang et al, 2013) and forms an extremely stable Fe(II) complex with a stability constant of 10 21.3 (Banks & Bystroff, 1959); stronger than that of Fe(II)-EDTA (Morel & Hering, 1993). In the presence of SRFA, multiple background measurements were performed in the presence of phenanthroline and averaged to account for the absorbance of SRFA alone.…”

A new spectrophotometric method for determination of EDTA in water using its complex with Mn(III)

“…Molecular spectroscopy is fast, simple to apply, inexpensive, and offers high sensitivity and accuracy, although it has rarely been used for the quantification of EDTA [22][23][24]. In the work of Hamano et al [23], EDTA was quantified indirectly using 4,7-diphenyl-1,10-phenanthroline-disulfonic acid to displace EDTA from the Fe(III)-EDTA complex, producing a colored complex that absorbed at 535 nm.…”

“…In the work of Hamano et al [23], EDTA was quantified indirectly using 4,7-diphenyl-1,10-phenanthroline-disulfonic acid to displace EDTA from the Fe(III)-EDTA complex, producing a colored complex that absorbed at 535 nm. Wang et al [24] determined EDTA indirectly by the reduction of excess Fe 3+ (that was not complexed with EDTA) to Fe 2+ , with the latter forming a colored complex with the 1,10-phenanthroline ligand.…”

“…The methods that have been developed for this purpose include gas chromatography [7,8], chemiluminescence [9,10], fluorescence [11], ion chromatography [12], high performance liquid chromatography (HPLC) [13][14][15][16][17][18][19][20][21], and molecular spectroscopy [22][23][24].…”

Highly Sensitive Determination of Ethylenediaminetetraacetic Acid Using a Permanganate Chemiluminescence System Catalyzed by Gold Nanoparticles

“…Other methods reported for the determination of EDTA include spectrophotometry, [15][16][17] fluorometry, 6,8,18 mass spectrometry, 19 atomic-absorption spetrometry, 20 electrochemistry, 9,21,22 and capillary electrophoresis. 23,24 Most of these methods are timeconsuming and expensive in terms of reagent consumption and the cost of instrumentation.…”