Catalytic method for determining traces of selenium

West, Philip W.; Ramakrishna, T. V.

doi:10.1021/ac60262a013

Cited by 54 publications

(8 citation statements)

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“…This procedure has been refined into a sensitive analytical method for the determination of trace amounts of Se (West and Ramakrishna, 1968). Gitler (1958) studied the Secatalyzed reduction of Methylene Blue by cysteine and suggested that this might be an appropriate model for the biological function of Se.…”

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confidence: 99%

Selenium as a catalyst for the reduction of cytochrome c by glutathion

Levander¹,

Morris²,

Higgs³

1973

Biochemistry

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Selenite at 10-5-10-6 M is a n effective catalyst for the reduction of cytochrome c by glutathione (GSH). Selenocystine was more effective and selenate less effective than selenite. Selenomethionine had no catalytic effect. A strong catalysis of selenite on the reduction of cytochrome c was still observed when mercaptoethylamine or cysteine replaced GSH as the thiol, but smaller catalytic effects of Se were seen when thioglycolate or mercaptoethanol was used in lieu of GSH. Cysteine was a more active reductant for cytochrome c than GSH either in the presence or absence of Se. Dithiothreitol and 2,3-dimercaptopropanol were both potent reducing agents for cytochrome c without Se, but a catalytic

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confidence: 99%

Selenium as a catalyst for the reduction of cytochrome c by glutathion

Levander¹,

Morris²,

Higgs³

1973

Biochemistry

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“…The surface chemistry of the modified HSPE fibers was characterized with a Nicolet20SX‐B Fourier transform infrared (FTIR) spectrometer. The content of functional groups on the surface of the fibers was measured by means of a methylene blue absorbing method described in the literature 16…”

Section: Methodsmentioning

confidence: 99%

Grafting of multifunctional groups onto the surface of high‐strength polyethylene fibers and the interface of their composites

Chen

2005

J of Applied Polymer Sci

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High-strength polyethylene (HSPE) fibers were oxidated via chemical reactions in an acidic medium, and the carboxyl group was transferred into the acyl chloride and then reacted with pentaerythritol or diethylene triamine to graft the multifunctional group compounds onto the surface of the HSPE fibers. Subtractive Fourier transform infrared spectroscopy and the methylene blue absorbing method were used to study the functional groups on the surface of the modified fibers and their content. The results show that the polar functional groups, including OCOOH, OOH, and ONH 2 , were introduced onto the surface of the HSPE fibers, and the polar groups improved the wettability. The interface shear stress (IFSS) of the composites that were made from modified fibers and epoxy was measured by means of the microdebond method. The results show that the IFSS was greatly increased by the grafting of pentaerythritol or diethylene triamine onto the HSPE fiber surface.

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“…Catalytic spectrophotometric methods offer excellent alternative choices for the determination of trace concentrations of many elements because of their simplicity and specificity (26)(27)(28)(29)(30). While their detection limits are such that they cannot compete with hydride generation AAS, they are still appropriate to meet many analytical needs (especially when properly optimized).…”

Section: Introductionmentioning

confidence: 99%

“…While their detection limits are such that they cannot compete with hydride generation AAS, they are still appropriate to meet many analytical needs (especially when properly optimized). West and Ramakrishna reported a method based on the reduction of methylene blue by sodium sulfide (27). Kawashima and Tanaka (28) proposed a very sensitive procedure for selenium based on the catalytic reduction of 1,4,6,11-tetraazanaphthacene, but the method is subject to interference from several ions including tellurium.…”

Section: Introductionmentioning

confidence: 99%

“…concentration, the T-T molar absorptivity of the donor need not be known. One could similarly measure the kinetics of heat released by the excited triplet states on a time scale from nanoseconds to microseconds by using photothermal calorimetry methods (20, [26][27][28]. More structurally selective spectroscopies, such as time-resolved ESR (29) and Raman spectroscopy (30), could also be used to discriminate between the decay kinetics of the excited donor and products of the quenching process.…”

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confidence: 99%

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