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R.G. Milkey

Publications and source records attributed to R.G. Milkey.

8 recordsLinked to original sources
USGS2002

Stability of dilute solutions of uranium, lead, and thorium ions

Standard solutions and samples containing a few micrograms of metallic ions per milliliter are frequently used in determination of trace elements. It is important to know whether the concentrations of such solutions remain constant from day to day. The stability of dilute solutions of three metallic ions-uranium, lead, and thorium-has been investigated. Solutions containing concentrations of metallic ions, ranging from 1000 to 0.1 γ per milliliter, were allowed to stand for approximately 2.5 months, and then the metallic ion content of those solutions that had lost strength was determined. Both adsorption and hydrolysis variously influenced the solute loss, but the minimum pH at which loss of concentration of lead and uranium occurred seemed to coincide with the pH at which the hydrolyzed metal ions began to precipitate. No increase in the stability of the solutions was obtained by substituting polyethylene containers for borosilicate glass. The solutions that lost strength could not be restored promptly to the original concentration by manual means, such as shaking them vigorously for several minutes.

Analytical Chemistry↗
USGS2002

Spectrophotometric study of the thorium-morin mixed-color system

A spectrophotometric study was made of the thoriummorin reaction to evaluate the suitability of morin as a reagent for the determination of trace amounts of thorium. At pH 2, the equilibrium constant for the reaction is 1 x 10 6 , and a single complex having a thorium-morin ratio of 1 to 2 is formed. The complex shows maximum absorbance at a wave length of 410 m μ , and its absorbance obeys Beer's law. The absorbance readings are highly reproducible, and the sensitivity is relatively high, an absorbance difference of 0.001 being equivalent to 0.007 γ of ThO 2 per sq. cm. The effects of acid, alcohol, and morin concentration, time, temperature, and age of the morin reagent as well as the behavior of morin with zirconium(IV), iron(III), aluminum(III), ytterbium(III), yttrium(III), uranium(VI), praseodymium(III), lead(II), lanthanum(III), and calcium(II) ions are discussed. A method is presented for the determination of thorium in pure solutions. Appropriate separations for the isolation of thorium may extend the usefulness of the method and permit the determination of trace amounts of thorium in complex materials.

Analytical Chemistry↗
USGS2002

Potassium bromide method of infrared sampling

In the preparation of potassium bromide pressed windows for use in the infrared analysis of solids, severe grinding of the potassium bromide powder may produce strong absorption bands that could interfere seriously with the spectra of the sample. These absorption bands appear to be due to some crystal alteration of the potassium bromide as a result of the grinding process. They were less apt to occur when the coarser powder, which had received a relatively gentle grinding, was used. Window blanks prepared from the coarser powders showed smaller adsorbed water peaks and generally higher over-all transmittance readings than windows pressed from the very fine powders.

Analytical Chemistry↗
USGS2002

A fluorimetric study of the thorium-morin system

Thorium reacts with morin to yield a yellow complex that fluoresces when irradiated with ultraviolet light. The effect on the fluorescence of such variables as concentration of acid, alcohol, thorium, morin, and complex; time, temperature and wave length of exciting light are studied to determine experimental conditions yielding maximum fluorescence. The effects of Zr+4, Al+3, Fe+3, Ca+2 and La+3 are discussed. The fundamental relationships between light absorption and fluorescence are expressed in a general equation that applies to a three-component system when the fluorescence is measured in a transmission-type fluorimeter. This general equation is used to obtain an expression for the fluorescence of the thoriummorin system. Equations, derived from experimental data, relate both the fraction of thorium reacted to form complex and the fraction of unquenched fluorescence to the concentration of uncombined morin. These functions, when combined with the general equation, give an expression whichrelates the total net fluorescence to the amount of uncombined morin in the solution. This last equation can be used to determine the one region for the concentration of uncombined morin that gives maximum sensitivity for the system. Calculated standard curves are in good agreement with experimental curves.

Journal of the American Chemical Society↗