Quantitative Infrared Analysis of Apatite Mixtures

Abstract

air under rather extreme conditions of sulfur content and times of standing.The routine use of this acidic-type solvent is recommended only for mercaptan samples known to contain a relatively large amount of elemental sulfur. For samples containing little or no elemental sulfur the regular titration solvent may be satisfactorily used. In fact, the use of the more basic solvent is mandatory when it is desired to determine both hydrogen sulfide and mercaptans on a sample which does not contain elemental sulfur. It is recommended that a nitrogen blanket be used with both solvents as a precautionary measure.In the experimental studies there were indications that the initial product of the reaction of elemental sulfur and mercaptan sulfur was the monoalkyl disulfide ion, (RSS)-, which decomposed to the sulfide ion on standing.Additional standing time in presence of excess elemental sulfur promoted the formation of inorganic polysulfides.In studies showing the effect of the organic substituent groups of the mercaptan it was indicated that phenyl, n-butyl, and ferf-butyl groups tended to form decreasing amounts of inorganic polysulfides in that order. ACKNOWLEDGMENTThe authors wish to thank Marjorie T. Walker for her very capable technical assistance in carrying out the experimental work and the Humble Oil & Refining Co. for permission to publish this paper.

Clinical Applications of Infrared Spectroscopy. Analysis of Renal Tract Calculi

“…The availability of an infrared recording spectrophotometer in this laboratory and information concerning the successful application of infrared spectroscopy to the identification of inorganic salts (10), minerals, and rocks (5, 6), as well as a recent publication on the infrared spectrophotometric analysis of dental enamel apatite (4) led to the application of this technique to the analysis of urinary tract calculi. Beischer (1) briefly reported analyses of renal calculi by infrared spectropho- Rossie, N. Y.…”

On the influence of etch pits in the overall dissolution rate of apatite basal sections

“…The spectra were obtained with the attenuated total reflectance (ATR) in the "Golden Gate" set-up for a ZnSe crystal (unpolarized light, θ = 45 • ). Spectra were recorded in the 700-1350 cm −1 wave number range with a resolution of 2 cm −1 at room conditions for 100 s. A baseline correction was employed, and data were analysed by the area and intensity methods (Fischer and Ring 1957). The penetration depth of the light was defined as the distance where the evanescent electric field, which penetrates the sample, decreases by a factor of e (Buffeteau et al 1996).…”

Ποιοτικος Και Ποσοτικος Προσδιορισμος Αργιλικων Ορυκτων Και Μαρμαρυ- Γιων Με Φασματα Υπερυθρης Ακτινοβολιας

“…Αρκετοί ερευνητές έχουν ασχοληθεί με την ποιοτική και ποσοτική ανάΚυστ] των ορυκτών με υπέρυθρη ακτινοβολία. Οι περισσότερες αναφορές στη βιβλιογραφία απαντώνται στη δεκαετία του 1950 (Keller 1950, , Winchell 1951, Miller 1952, Stimson 1952, Farmer 1955, Fisher 1957και Lyon 1959. Φαίνεται ότι η σύγχρονη οργανολογία που αναπτύχθηκε, απωθούσε την προσοχή των ερευνητών σε πιο σύγχρονα αναλυτικά όργανα όπως π.χ.…”