Iron® picolinate

Clement and Paris [17] have devised a pair of methods for the determination of cobalt in steels, especially materials encountered in the nuclear industry. In the first technique, suitable for the analysis of solutions containing 8 to 160 mM cobalt(II), iron(III) is used to oxidize cobalt(II) in a picolinic acid medium, after which the resulting iron(II) is titrated po-tentiometrically with a standard solution of cerium(IV). An alternative procedure, for concentrations of cobalt(II) below 8 mM, involves a constant-current coulometric titration with electrogenerated cerium (IV) to measure the iron(II) that arises from the original reaction between cobalt(II) and iron(III). 

Information of the Gif system has been summarized,1055 1123 and new results, including new oxidants such as bis(trimethylsilyl) peroxide,1124 the synergistic oxidation of saturated hydrocarbons and H2S,1125 studies with the Fe3+-picolinate complex encapsulated within zeolites,1126 and the use of Udenfriend s system under Gif conditions1127 were disclosed. Gif-type oxidations were found to be moderately stereoselective.1128 Iron/zinc-containing species involved in Gif-type chemistry were synthesized, and their reactivity and catalytic behavior were studied.1129... 

Related to amino acids is picolinic add (8), which is present at high concentrations in dormant tissues such as plant seeds and whose involvement in the quiescent state may involve iron chelation. Also mugineic acid (9) possesses strong Fe111 chelating properties. This amino acid derivative has been isolated from the roots of rice plants and has been found to have a strong stimulatory effect on Fe uptake. The crystal structure of a complex of Co111 shows that the anion of (9) can function as a hexadentate chelate.38... 

Campbell WW, Beard JL, Joseph LJ, et al. 1997. Chromium picolinate supplementation and resistive training by older men Efects on iron-status and hematologic indexes. Am J Clin Nutr 66 944-949. 

The bis(picolinate)iron(II) complex [Fe (PA)2 PAH = picolinic acid, 2-pyridinecarboxylic acid] in combination with hydrogen peroxide (HOOH) is an effective Fenton reagent for organic substrates, and has reactivities and product profiles that are closely similar to those for traditional aqueous Fenton reagents. This system reacts with hydrocarbon substrates (c-CeHu) via an intermediate that results from the nucleophihc addition by HOOH to the electrophilic Fe (PA)2 center (equation 78). ... 

The rate of electron transfer between the tris(dithiocarbamato) complexes Fe(Me2dtc)3 and [Fe(Me2dtc)3]BF4 has been measured by the line-broadening technique to be (1-5 + 04) x 10 dm moP s at - 57 C. (328) A similar electron transfer study involving tris-phenanthroline-iron(ii) and -iron(iii) complexes has been performed. (329) The exchange kinetics of Ni(di-R,R -dtc)2 with various nitrogen bases yield rate constants at 5°C of 12-5 x 10" s and 6-2 X 10 s for 3-picoline and 4-picoline respectively. (330)... 

Some new lanthanide porphyrin complexes of general formula Ln(iii)TAP(/i-diketonate), where TAP = tetraarylporphine, have been prepared (468,469) and their shift reagent capabilities assessed. The complexes of the early lanthanides (Pr, Nd, Sm, Eu) induce very small shifts whereas the complexes of Tb, Dy, and Ho produce quite large low frequency shifts in y-picoline. Analogous shift reagents based on silicon, germanium, low-spin iron, (517, 518) and cobalt (519) have been reported. 

Other kinetic studies of complexation using relaxation techniques can be found in Bridger et al. (1983) [hydroxo and chloro complexes of Fe(III)], Bridger et al. (1982) [complexation of Fe(III) by picolinic and dipicolinic acids], Strahm et al. (1979) (complexation of aqueous iron chloride), and Patel and Taylor (1973) (complexation of magnesium pyrophosphates). 

Bridger, K., R.C. Patel, and E. Matijevic. 1982. Thermodynamics and kinetics of iron (III) ion by picolinic and dipicolinic acids. Polyhedron 1 269-275. 

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