Spectrophotometric Determination of Iron in Strong Alkali Media 4,7-Dihydroxy-1,10-phenanthroline as Iron(II) Organic Chelation Report

The spectrophotometric determination of dissolved oxygen and other uses of 4,7-dihydroxy-1, 10- phenanthroline

“…The absorption spectra between 350 and 650 nm. of the iron(II) and iron(III) compounds are shown in Figure VIII-2.The wavelength of maximum absorbance of the iron(II) compound, 520 nm., and molar absorptivity, e = l4,800 liter-mole"^-cm"^, found were the same as reported earlier by Schilt and co workers(60). These workers showed that the molar absorptivity of the iron(II) compound is independent of the concentration of alkali; in the present study this was shown to be true also in ammonia buffers as dilute as 0.2 M NH4OH plus 0.1 M NH4CI (pH = 9.1).…”

“…Of the compounds listed in Table II A -synthesis; B -colorlmetrlc study; C -reduction potential; D -formation constant of Iron compound; E -pH markers In Isoelectric focusing; F -NMR spectrum; G -infrared spectrum; H -determination of copper; I -determination of iron; J -acid dissociation constants; K -Mossbauer spectrum; L -decomposition of metal derivatives by acid or base; M -catalyst; N -kinetics of oxidation of ferrous derivative with peroxydisulfate; 0 -mixed-llgand compounds; P -solubility of perchlorate. A (14,66); B (26); C (31); E (52); G (29,65); I (29,60); J (42); K (18); L (11,13); M (17,57); N (11); 0 (68); P (12) A (14,54,66) A (14,66) to determine the reduction potentials of the iron (III,II) couples. Mixed-ligand compounds such as these, and the simple tris-chelated iron derivatives of other hydroxyphenanthrolines should provide a host of indicators with reduction potentials lower than 0.8 volt.…”

“…When Schilt, Smith, and Heimbuch first introduced the use of ^,7-dihydroxy-l,10-phenanthroline as a reagent for the colorimetric determination of iron in strong alkali, they noted that commercial grades of sodium hydroxide invariably contain appreciable amounts of iron, and it is preferable to use the reagent in solution form in carefully measured amounts and to correct for the iron in these solutions by carrying through a blank determination (60). They also noted that iron may be removed from solutions of sodium hydrosulfite by extraction as tris(4,7-diphenyl-l,10-phenanthroline)iron(II) into n-hexyl alcohol, that is, as the ferrous derivative of bathophenanthroline.…”

Removal of iron, copper, cadmium, cobalt, and nickel from sodium hydroxide by precipitation and extraction with phenyl-2-pyridyl ketoxime

“…Reduction of iron(III) with hydrogen proceeds slowly at room temperature, but the rate is considerably increased at 100 °C. After the purification procedure (without removal of dissolved palladium) was carried out on solutions initially containing 7 X 10"5 M iron(III), the iron which remained in solution was estimated spectrophotometrically using 4,7-dihydroxy-l,10-phenanthroline (7) with 10-cm cells. Figure 1 shows absorbance as a function of time and temperature.…”

In dialyzed squid axons oxidative stress inhibits the Na+/Ca2+ exchanger by impairing the Cai2+-regulatory site

“…In (25,41,42,45,46). Actually, phenanthroline has already been used in studies of redox modifications of Na ϩ /Ca 2ϩ exchange activity in mammalian heart sarcolemmal vesicles (41).…”