Open Access. Powered by Scholars. Published by Universities.®
Physical Sciences and Mathematics Commons™
Open Access. Powered by Scholars. Published by Universities.®
Articles 1 - 3 of 3
Full-Text Articles in Physical Sciences and Mathematics
Involvement Of Free Radicals In Peroxidatic Reactions Catalyzed By Chloroperoxidase, David P. Provencal
Involvement Of Free Radicals In Peroxidatic Reactions Catalyzed By Chloroperoxidase, David P. Provencal
Senior Scholar Papers
The mechanism of chloroperoxidase (CPO)-catalyzed peroxidatic reactions of several substituted hydroquinones was studied at various hydrogen peroxide concentrations. The pathway was studied using cytochrome c as the radical trapping agent. As the hydroquinones became more hindered there was a difference in the amount of radicals trapped. For hydroquinone, 59.3% radical pathway, and methylhydroquinone, 81.4% radical, the difference in radicals trapped is due to a difference in pathway. For 2,3-dimethylhydroquinone (75.4%), trimethylhydroquinone (44.5%), and t-butylhydroquinone (0%) other non-peroxidatic reactions are noticed. Thus, for the more substituted hydroquinones the difference in radicals trapped can not be assigned to a difference in radical …
Paleoenvironmental Analysis Of Three Subfossil Coleopteran Faunas From The Toklat River Drainage, Central Alaska, Lisa L. Churchill
Paleoenvironmental Analysis Of Three Subfossil Coleopteran Faunas From The Toklat River Drainage, Central Alaska, Lisa L. Churchill
Senior Scholar Papers
Three sediment samples were collected from exposures along the Tok lat River. Central Alaska and analyzed for subfossil Coleopteran remains. Two samples arc Holocene in age (650 ± b.p .. and submodem) and the other is believed to be laic Pleistocene in age, based on stratigraphic interpretations. The Pleistocene fauna was representative of a tundra environment adjacent to a fluvial system. The older Holocene sample was indicative of a point bar deposit wi rh sl ightly moister conditions. although rhe occurrence of several tundra species was also noted. These tundra species were evidently able to make the transition from their …
Characterization And Implementation Of A Continuos Flow Trace Metal Preconcentration System For Inductively Couples Plasma Atomic Emission Spectrometry, Robert N. Sibley
Characterization And Implementation Of A Continuos Flow Trace Metal Preconcentration System For Inductively Couples Plasma Atomic Emission Spectrometry, Robert N. Sibley
Senior Scholar Papers
A continuous flow pre-concentration system for analysis of trace metals in natural waters was characterized and used to determine the copper(II) and lead(II) concentrations in seawater from Penobscot Bay, Maine. Pre-concentrated samples were analyzed by inductively coupled plasma atomic emission spectrometry (ICP-AES). System characterization involved elucidation of the thermodynamic complexation constants, KCu(II) and KPb(II), for Cu(II) and Pb(II) with the pre-concentration column chromatographic material. This was done in aqueous media of known pH and ionic strength. The column contained 8-hydroxyquinoline immobilized on Toyopearl HW-75 fractogel chromatographic resin. The buffer system used for metal binding experiments was an equimolar mixture of …