Methods for analysis of the mononuclear and binuclear manganese(III) cyano-complexes

López-Cueto, Guillermo; Alonso-Mateos, A.; Ubide, Carlos; Campo-Martinez, G. del

doi:10.1016/0039-9140(88)80185-1

Cited by 5 publications

(4 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Prepared according to the method of Lower and Fernelius. 19 Spectrophotometric assays by the methods previously reported 20 indicated a content of at least 95%. Hexacyanomanganate(iv) solution, 5.2 3 10 23 mol l 21 .…”

Section: Reagentsmentioning

confidence: 79%

Improved selectivity in multicomponent determinations through interference modelling by applying partial least squares regression to kinetic profiles

Kappes¹,

Rodríguez-Medina²,

Ubide³

et al. 1998

Analyst

View full text Add to dashboard Cite

Binary and ternary mixtures of cysteine, tyrosine and tryptophan were used to show how kinetic methods together with partial least squares regression (PLSR) can be used to overcome interferences in multicomponent determinations. Two methods were compared: an equilibrium method which uses the characteristic UV spectra of amino acids and a kinetic method which follows the reaction kinetics of the oxidation of the amino acids by hexacyanomanganate(iv). In both cases, multi-wavelength detection with a diode-array spectrophotometer was used. The results obtained from the two methods are critically compared. Lower concentrations of tyrosine and tryptophan can be determined by the equilibrium method because of their high absorptivities. On the other hand, the kinetic method, in conjunction with PLSR, can be considered an example of how selectivity can be improved. This allowed the resolution of mixtures of tyrosine and tryptophan in the presence of several complex spiked matrices (aqueous extracts of feed samples that interfere to different extents) without any previous separation.

show abstract

Section: Reagentsmentioning

confidence: 79%

Improved selectivity in multicomponent determinations through interference modelling by applying partial least squares regression to kinetic profiles

Kappes¹,

Rodríguez-Medina²,

Ubide³

et al. 1998

Analyst

View full text Add to dashboard Cite

show abstract

“…Prepared according to the method of Lower and Fernelius. 11 Spectrophotometric assays by the methods reported previously 12 indicated a content of at least 95%.…”

Section: Reagentsmentioning

confidence: 80%

Individual Kinetic Determinations Using Partial Least Squares Calibration

López-Cueto¹,

Rodríguez-Medina²,

Ubide³

1997

Analyst

View full text Add to dashboard Cite

The slow oxidation reactions of cysteine, tyrosine and tryptophan by hexacyanomanganate(IV) were used to investigate partial least squares calibration (PLS) as a method to be applied to the kinetic determination of individual species. All the three reactions are first order in hexacyanomanganate(IV) concentration and the reactions with cysteine and tyrosine are first order in amino acid concentration. The stoichiometry was studied in each case. The determination results were always compared with those obtained by applying the initial rate method to the same kinetic runs. When suitable kinetic curves are obtained and the initial rate is easily determined, both methods give similar results; however, when the initial rate is not easily determined (too fast reaction, slope that changes very quickly, etc.) the results obtained with PLS are better (better precision and wider dynamic range). Moreover, and in contrast to the initial rate method, PLS allowed tryptophan to be determined in the presence of some different feed matrices, provided the calibration set was of the same nature as the samples. This advantage is of general application and makes the analytical method more robust. PLS was tested on uncatalysed reactions but it could equally be applied to catalysed reactions.

show abstract

“…Reagents Potassium hexacyanomanganate(II1) was prepared according to the method of Lower and Fernelius (13) and characterized as described previously (14). Nitric acid, sodium nitrate, and manganese(I1) sulfate of analytical reagent grade and distilled, deionized water were used throughout.…”

Section: Apparatusmentioning

confidence: 99%

“…We have been looking for some experimental proof of the existence of the postulated intermediates (steps [12]- [14]), but neither spectral (uv-visible) nor electrochemical (cyclic voltammetry) evidence has been found, probably because the steady-state concentrations lie under their detection limits. Nonetheless, the existence of the intermediates has been postulated to explain the pseudo-first-order kinetics found.…”

Section: Kinetics Of Disproportionationmentioning

confidence: 99%

A voltammetric study of the kinetics of the hexacyanomanganate(III) disproportionation in acidic medium

López-Cueto¹,

Ubide²

1991

Can. J. Chem.

View full text Add to dashboard Cite

GUILLERMO LOPEZ-CUETO and CARLOS UBIDE. Can. J. Chem. 69, 21 12 (1991). The fast disproportionation of hexacyanomanganate(II1) in acidic medium yields Mn(CN)6'--and Mn(H20)6". The reaction has been studied by amperometry, with a rotating platinum-disk electrode, at a 1.0 V (vs. SCE) constant potential, in the acidity range 0.01-2.0 M and at temperatures between -5 and 15°C. A reversible one-electron process takes place with a 0.85 V (vs. SCE) half-wave potential that is not dependent on acidity. The reaction kinetics is pseudo-first order in s-' M-' , respectively. A mechanism is proposed where the three terms of kobs are assigned to pathways involving hexacyanomanganate(II1) in three different states of protonation. From the effect of temperature the activation parameters, AH# and AS#, for each pathway are also reported.

show abstract

Methods for analysis of the mononuclear and binuclear manganese(III) cyano-complexes

Cited by 5 publications

References 10 publications

Improved selectivity in multicomponent determinations through interference modelling by applying partial least squares regression to kinetic profiles

Improved selectivity in multicomponent determinations through interference modelling by applying partial least squares regression to kinetic profiles

Individual Kinetic Determinations Using Partial Least Squares Calibration

A voltammetric study of the kinetics of the hexacyanomanganate(III) disproportionation in acidic medium

Contact Info

Product

Resources

About