Aqueous Inorganic Solutions Research Articles

Trace organic contaminant concentration by freezing—II: Inorganic aqueous solutions

The presence of dissolved inorganic salts in aqueous solution impairs recovery efficiency of organic solutes by a freeze concentration procedure shown to be effective in the absence of salt. This effect is observed in the recovery of acetophenone and various phenols. Although previous tests demonstrated that mixing rate is not critical in the recovery of trace solutes by freeze concentration of distilled water solutions, it is important when dissolved salts are present. Higher mixing rates increase organic solute recovery. A relationship exists between salt content, mixing rate during the freezing process and organic solute recovery efficiency. Adjustment of sample pH becomes a factor in organic solute recovery. This is increasingly important as volume concentration ratio increases. Recovery is greater from acidic solutions. Freeze concentration of a complex mixture of phenolic materials showed no selectivity. All components were equally concentrated. This suggests the addition of a known quantity of an organic material to field samples as an internal reference. The reference would permit correction of results for losses induced by salt, inadequate mixing, etc. No effect on recovery is observed when iron, calcium, magnesium or copper is added to dilute organic aquesous solutions in excess of theoretical maximum coordination concentrations. Organometallic complexes, if they form, do not alter freeze concentration recovery efficiency. The advantages of combined freeze concentration and gas-liquid chromatographic analyses over conventional analytical procedures for separating and identifying complex mixtures of trace organics at less than 1 mg/l initial concentration is demonstrated with a mineralized industrial waste water.

Trace organic contaminant concentration by freezing—I. Low inorganic aqueous solutions

Freeze concentration of μ/1 and mg/1 concentrations of various organics in aqueous solution may be quantitatively accomplished in single-stage or a cascade of single-stage steps in the absence of dissolved inorganic salts. Mixing is not an important variable at ice-salt temperature of approximately −12°C. Single-stage freezing of 200 ml requires less than 20 min at the ice-salt temperature. Complex mixtures of organics are concentrated without loss of efficiency. For the experimental system used, mechanical-geometric factors limited final volumes of liquid to approximately 30 ml regardless of initial sample volume. At smaller volumes, solute separation was not complete. The organics tested were phenol and various substituted phenols, propionic through caproic volatile fatty acids and acetophenone. No effect on recovery efficiency was found for organic dissociation potential; molecular size or weight; or nature, location and number of substituent groups. Freeze concentration is a valuable laboratory technique, particularly for volatile or reactive compounds which may be chemically altered or selectively separated by thermal or solvent concentration procedures.

The Rates of Reaction of the Hydrated Electron in Aqueous Inorganic Solutions1

The Rates of Reaction of the Hydrated Electron in Aqueous Inorganic Solutions¹

Effects of Inorganic Aqueous Solutions to the Induction Periods of the Reaction of KMnO4-H2C204.2H20

Effects of Inorganic Aqueous Solutions to the Induction Periods of the Reaction of KMnO4-H2C204.2H20

Chemical effects of ionizing radiations on aqueous inorganic solutions

This paper deals specifically with the chemical changes induced in aqueous solutions under irradiation by alpha, beta, gamma, and X-ray radiation.

Reviews-Note on partially miscible aqueous inorganic solutions

Reviews-Note on partially miscible aqueous inorganic solutions

Societies and Academies

LONDON. Chemical Society, March 29.—Annual General Meeting.— Prof. Thorpe, President, in the chair.—After the delivery of the presidential address, a ballot, was held for the election of officers and council for the ensuing year.—At an extra meeting held in the evening, Sir H. E. Roscoe, Vice-President, delivered the Bunsen Memorial Lecture.—April 5.—Prof. J. M. Thomson, Vice-President, in the chair.—The following papers were read:—The liquefaction of a gas by “self-cooling” (a lecture experiment), by G. S. Newth. The author exhibits the liquefaction of nitrous oxide by rapidly passing the gas from the slightly-warmed storage cylinder through a fine copper tube spiral inserted in a vacuum-jacketed test-tube.—Note on partially miscible aqueous inorganic solutions, by G, S. Newth.—The decomposition of chlorates. Part ii. Lead chlorate, by W. H. Sodeau. The slow decomposition of lead chlorate by heat consists of the two independent reactions: (1) Pb(ClO3)2=PbCl2 + 3O2, and (2) Pb(ClO3)2=PbO2+Cl2 + 2O2. The reaction PhO2-hCl2=PbCl2 + O2 simultaneously proceeds to a greater or less extent —The bromination of benzeneazophenol, by J. T. Hewitt and W. G. Aston.—A new glucoside from willow-bark, by H. A. D. Jowett. The author has isolated, from the bark of a species of Salix, the glucoside of metahydroxybenzaldehyde and gives to it the name salinigrin.—Alkylation by means of dry silver oxide and alkyl iodides, by G. D. Lander. Dry silver oxide and ethyl iodide react with acetanilide yielding ethyl i-acetanilide, C6H5N: C(OEt)Me.—The interaction of mesityl oxide and ethyl sodiomethylmalonate, by A. W. Crossley. By the condensation of mesityl oxide with ethyl sodiomethylmalonate, ethyl trimethyldihydroresorcylate, C12H13O4, is obtained; on hydrolysis it yields trimethyldihydroresorcinol,