Geology topics

Marvin C. Goldberg

Publications and source records attributed to Marvin C. Goldberg.

7 recordsLinked to original sources

USGS2008

The aqueous photolysis of ethylene glycol adsorbed on geothite

Suspensions of goethite (α-FeOOH) were photolyzed in aerated ethylene glycol-water solutions at pH 6.5, with ultraviolet light in the wavelength range300–400 nm. Under these conditions, formaldehyde and glycolaldehyde were detected as photoproducts. Quantum yields of formaldehyde production ranged from 1.9 7times; 10 -5 to 2.9 × 10 -4 over the ethylene glycol concentration range of 0.002-2.0 mol/ℓ, and gave evidence that the reaction occurred at the goethite surface. Quantum yields of glycolaldehyde were 20% less than those of formaldehyde, and displayed a concentration-dependent relationship with ethylene glycol similar to that of formaldehyde. Immediately after photolysis, Fe 2+ was measured to be 4.6 × 10 -7 mol/ℓ in an aerated suspension containing 1.3 mol/ℓ ethylene glycol, and 8.5 × 10 -6 mol/ℓ in the corresponding deoxygenated suspension. Glycolaldehyde was not generated in the deoxygenated suspensions. These results are consistent with a mechanism involving the transfer of an electron from an adsorbed ethylene glycol molecule to an excited state of Fe 3+ (Iron[III]) in the goethite lattice, to produce Fe 2+ and an organic cation. In a series of reactions involving O 2 , FeOOH, and Fe 2+ , the organic cation decomposes to form formaldehyde and the intermediate radicals “OH and” CH 2 OH. OH reacts further with ethylene glycol in the presence of O 2 to yield glycolaldehyde. Aqueous photolysis of ethylene glycol sorbed onto goethite is typical of reactions that can occur in the aquatic environment.

Photochemistry and Photobiology↗

USGS1992

The aqueous photolysis of α-pinene in solution with humic acid

Terpenes are produced abundantly by environmental processes but are found in very low concentrations in natural waters. Aqueous photolysis of solutions containing α-pinene, a representative terpene, in the presence of humic acid resulted in degradation of the pinene. Comparison of this reaction to photolysis of α-pinene in the presence of methylene blue leads to the conclusion that the reactive pathway for the abiotic degradation of α-pinene is due to reaction with singlet oxygen produced by irradiation of the humic material. The initial product of single oxygen and α-pinene is a hydroperoxide. Since humic materials are prevalent in most natural waters, this mechanism of photodecomposition for α-pinene probably also applies to other terpenes in surface waters and may be reasonably considered to contribute to their low environmental concentration.

Journal of Contaminant Hydrology↗

USGS1985

AQUATIC PHOTOLYSIS OF OXY-ORGANIC COMPOUNDS ADSORBED ON GOETHITE.

Organic materials that will not absorb light at wavelengths longer than 295 nanometers (the solar wavelength cutoff) may nevertheless, undergo electron transfer reactions initiated by light. These reactions occur when the organic materials are adsorbed as ligand complexes to the surface of iron oxy-hydroxide (goethite). The adsorbed materials can be either inner or outer coordination sphere complexes. Goethite was chosen as the iron oxyhydroxide surface because it has the highest thermodynamic stability of any of the oxyhydroxides in water and it can be synthesized easily, with high purity.

Conference Paper↗

USGS1984

PHOTOLYSIS OF GOETHITE WITH SORBED LOW MOLECULAR WEIGHT CARBOXYLATES.

Goethite ( alpha -FeOOH) is a common mineral constituent of suspended and bed sediments in aquatic environments. Many types of naturally-occurring organic molecules, including organic carboxylates, are known to sorb to its surface. Carboxylates should be susceptable to photo-oxidation. An experimental program was conducted with systems containing adsorbed films of oxalate, citrate, tartrate, glycolate, formate, maleate, fumarate, butanoate, and benzoate on Goethite, respectively. Photolytic effects were observed at pH 6. 5 and 5. 5.

Conference Paper↗

USGS1980

Extraction and concentration of phenolic compounds from water and sediment

Continuous liquid-liquid extractors are used to concentrate phenols at the ??g l-1 level from water into dichloromethane; this is followed by Kuderna-Danish evaporative concentration and gas chromatography. The procedure requires 5 h for 18 l of sample water. Overall concentration factors around 1000 are obtained. Overall concentration efficiencies vary from 23.1 to 87.1%. Concentration efficiencies determined by a batch method suitable for sediments range from 18.9 to 73.8%. ?? 1980.

Analytica Chimica Acta↗

USGS1977

Feasibility and technology for making remote measurements of solutes in water

An indepth evaluation of the available technology in the field of laser-Raman spectroscopy indicates that a TV-type detector, a single monochromator with a holographic grating, an entrance slit filter blocking the Rayleigh light, and a pulsed laser coupled to signal averaging electronics is the best combination of commercial equipment that is presently available for building a remote water-quality sensor. The resultant sensor would be capable of measuring oxyanions in water at concentrations from 10 to 50 milligrams per liter at distances from ground level to 30 meters above the sample. The main interferences would be ambient light, bioluminescence, and natural fluorescence, all of which are minimized when taking advantage of the signal generating and readout capability contained in this equipment package.

Journal of Research of the U.S. Geological Survey↗

USGS1973

Fluorescent spectroscopy, a technique for characterizing surface films

A relationship is established between fluorescent spectra obtained by using a light path through the liquid solution and the fluorescent spectra obtained by a direct reading of surface reflection (remote sensing). A brief review of quantum fundamentals provides the necessary information to conclude that "see-through" and reflectance spectra are identical in wavelength response. Many floating films contain fluorescent materials; thus fluorescent spectroscopic techniques were used to obtain the fluorescent spectra of lube oil, crude oil, and lignosulfonie acid in an effort to detect, identify, and quantify these representative fluorescent materials in water solutions. For each material tested the emission maximum was established. The emission maximum was then held constant while the absorption spectrum was recorded and the absorption maximum established. The complete spectral curves are presented.

Journal of Research of the U.S. Geological Survey↗