A microdiffusion method for the determination of fluorides

Frere, F. J.

doi:10.1016/0026-265x(62)90146-7

Cited by 19 publications

(4 citation statements)

References 6 publications

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“…Food samples which ranged from 0.2 to 1.2 g in mass were charred under infrared lamps for 3l / 2 h and then from crucibles with deionized water and perchloric acid in a nitrogen atmosphere to avoid carbonate formation. F was microdiffused from perchloric acid for 13 h at room temperature (23,24) into a NaOH solution and measured with a selective-ion electrode and the known addition technique (25) with a citrate-acetate buffer at pH 5.5.…”

Section: Selection and Preparation Of Samplesmentioning

confidence: 99%

Proton activation analysis for the measurement of fluorine in food samples

Shroy¹,

Kraner²,

Jones³

et al. 1982

Anal. Chem.

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Section: Selection and Preparation Of Samplesmentioning

confidence: 99%

Proton activation analysis for the measurement of fluorine in food samples

Shroy¹,

Kraner²,

Jones³

et al. 1982

Anal. Chem.

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“…Otherwise, the separation of fluoride by diffusion takes place for at least 24 hours at much higher temperatures (usually 60 °C) (2, 4, J). Thus, the use of silicone grease enables quicker separations of fluoride, but there was the possibility of the interference of components of silicone grease and their breakdown products, with subsequent spectrophotometric determinations of fluoride (3,10). It was desirable, therefore, to study the influence of silicone grease (and the products of its decomposition) on various spectrophotometric methods for the determination of fluoride.…”

Section: Figure 8 Egd Curves Of Dioctyl Sebacatementioning

confidence: 99%

“…Ranges of method: 0.5-10 µg(3, 15) and 0.25-10 µg (16, 17) 6. Determinations were made in 5 replicates.A.…”

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Influence of silicone grease on spectrophotometric methods for the determination of fluoride

Tušl¹

1969

Anal. Chem.

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Diffusion methods of the separation of fluoride are of very great importance for the determination of fluorine in biological and other materials. They involve liberating fluoride ions by mineral acids and their absorption in trapping solutions of alkali. As diffusion vessels, polyethylene bottles (1, 2), Conway dishes (3, 4), multicell trays (5), polyethylene stoppers (6), special dishes with two square chambers (7), and plastic Petri dishes (S) are used. In most diffusion methods, silicone grease is used to seal diffusion vessels in order to prevent any leakage of fluoride (4, 5, 7, 9,10). Polyethylene bottles and stoppers only need not be sealed; nevertheless, sealing bottles with wax was also recommended (2). Recently, Taves (10) found that fluoride passes into trapping solutions in the form of methylfluorosi lane if silicone grease is used for sealing; the diffusion of hydrogen fluoride was supposed earlier. In the presence of the simpliest silicone, hexamethyldisiloxane, the separation of fluoride is much more rapid. Therefore, a faster diffusion method for the separation of fluoride was proposed (8). Fluoride was liberated by 25% perchloric acid in the presence of a solution of hexa-

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“…6 The method is a modification of the combustion proDr. Thomas 9 Frere, 10 Hall, 11 ! 12 Schoniger, 13 Singer and Armstrong, 14 ) 15 and Wharton 16 to isolate and collect all the fluoride produced by the combustion.…”

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confidence: 99%