Determination of ferrous and total iron in silicate rocks by automated colorimetry

Whitehead, D. L.; Malik, S. A.

doi:10.1021/ac60353a054

Cited by 14 publications

(6 citation statements)

References 7 publications

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“…Fe(II)/total Fe ratios (Fe(II)/ΣFe) in the spinels were determined colorimetrically. 39,40 In this method, used for characterization. The initial set was used for XRD and XAFS studies.…”

Section: Methodsmentioning

confidence: 99%

“…Chemicals were ACS grade or better and were used as received. Fe(II)/total Fe ratios (Fe(II)/ΣFe) in the spinels were determined colorimetrically. , In this method, V(V) is reduced to V(IV) by Fe(II) during dissolution of the sample in acid. When 2,2′-bipyridyl (bipy) and buffer are added, V(IV) quantitatively reduces Fe(bipy) 3 3+ to red Fe(bipy) 3 2+ , which is measured spectrophotometrically.…”

Section: Methodsmentioning

confidence: 99%

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Incorporation of Technetium into Spinel Ferrites

Lukens

Magnani

Tyliszczak

et al. 2016

Environ. Sci. Technol.

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Technetium (Tc) is a problematic fission product for the long-term disposal of nuclear waste due to its long half-life, high fission yield, and to the environmental mobility of pertechnetate, the stable species in aerobic environments. One approach to preventing Tc contamination is using sufficiently durable waste forms. We report the incorporation of technetium into a family of synthetic spinel ferrites that have environmentally durable natural analogs. A combination of X-ray diffraction, X-ray absorption fine structure spectroscopy, and chemical analysis reveals that Tc(IV) replaces Fe(III) in octahedral sites and illustrates how the resulting charge mismatch is balanced. When a large excess of divalent metal ions is present, the charge is predominantly balanced by substitution of Fe(III) by M(II). When a large excess of divalent metal ions is absent, the charge is largely balanced by creation of vacancies among the Fe(III) sites (maghemitization). In most samples, Tc is present in Tc-rich regions rather than being homogeneously distributed.

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“…Fe(II)/total Fe ratios (Fe(II)/ΣFe) in the spinels were determined colorimetrically. 39,40 In this method, used for characterization. The initial set was used for XRD and XAFS studies.…”

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Incorporation of Technetium into Spinel Ferrites

Lukens

Magnani

Tyliszczak

et al. 2016

Environ. Sci. Technol.

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show abstract

“…Fe(II)/Fe(total) ratios were determined colorimetrically using a manual adaptation of the method described by Whitehead and Malik, and have an absolute uncertainty of 0.4%. 20,21 Two groups of borosilicate glasses were investigated. The first group, crucible glasses, was prepared in a vertical tube furnace by suspending a Pt / 4% Au crucible in the center of the tube.…”

Section: Methodsmentioning

confidence: 99%

Research program to investigate the fundamental chemistry of technetium

McKeown¹,

Buechele²,

Lukens³

et al. 2007

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“…However, with the development of studies on the speciation of elements and efforts to use the information on their levels (the geochemical 'fingerprint') to monitor processes taking place in the environment Niedzielski, 2009, Kozak et al, 2012), the interest in iron speciation has increased. Determinations of the levels of various forms of iron rely on colorimetric methods that utilise their selective ability to form colour complexes with sulphocyanateions (in the case of Fe(III), Tarafder and Thakur, 2005) and with 2,2'-dipyridyl (in the case of Fe(II), Whitehead and Malik, 1975), thus competing with the latest combined techniques (Gonzalvez et al, 2009). In determinations of total iron content, colorimetric methods have practically been replaced by spectrometric ones (Hosseinimehr et al, 2007).…”

Section: Introductionmentioning

confidence: 99%