Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

Chemistry

Chapman University

Series

2009

Articles 1 - 5 of 5

Full-Text Articles in Physical Sciences and Mathematics

Air-Sea Gas Exchange Of Co2 And Dms In The North Atlantic By Eddy Covariance, Scott Miller, Christa Marandino, Warren J. De Bruyn, Eric S. Saltzman Jan 2009

Air-Sea Gas Exchange Of Co2 And Dms In The North Atlantic By Eddy Covariance, Scott Miller, Christa Marandino, Warren J. De Bruyn, Eric S. Saltzman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We report the first simultaneous eddy covariance flux measurements of CO2 and dimethylsulfide (DMS) over the open ocean for two North Atlantic cruises. After normalization for Schmidt number, the two gases give essentially identical gas transfer coefficients and wind speed dependences for the wind speed range 2-10 ms(-1). The data indicate a linear relationship between the gas transfer coefficient and mean wind speed, with measured gas transfer coefficients slightly above the Wanninkhof (1992) parameterization, particularly at low wind speeds. Citation: Miller, S., C. Marandino, W. de Bruyn, and E. S. Saltzman (2009), Air-sea gas exchange of CO2 and DMS in …

Go to article

Liquid Chromatography-Tandem Mass Spectrometry For The Determination Of Methylprednisolone In Rat Plasma And Liver After Intravenous Administration Of Its Liver-Targeted Dextran Prodrug, Shuang-Qing Zhang, Helen R. Thorsheim, Suman Penugonda, Venkateswaran C. Pillai, Quentin R. Smith, Reza Mehvar Jan 2009

Liquid Chromatography-Tandem Mass Spectrometry For The Determination Of Methylprednisolone In Rat Plasma And Liver After Intravenous Administration Of Its Liver-Targeted Dextran Prodrug, Shuang-Qing Zhang, Helen R. Thorsheim, Suman Penugonda, Venkateswaran C. Pillai, Quentin R. Smith, Reza Mehvar

Pharmacy Faculty Articles and Research

A specific and sensitive liquid chromatography (LC)-tandem mass spectrometric method for quantitative determination of methylprednisolone (MP) in rat plasma and liver was developed and validated using triamcinolone acetonide as an internal standard. Liquid-liquid extraction using tert-butyl methyl ether was used to extract the drug and the internal standard from plasma and liver. The separation of MP was performed on a C(18) column with a mobile phase of acetonitrile:0.5% formic acid aqueous solution (85:15, v/v) over 4 min. The assay was based on the selected reaction monitoring transitions at m/z 375 -> 161 for MP in plasma, 375 -> 357 for …

Go to article

A Collection Of Micrographs: Where Science And Art Meet, Vuk Uskoković Jan 2009

A Collection Of Micrographs: Where Science And Art Meet, Vuk Uskoković

Pharmacy Faculty Articles and Research

Micrographs obtained using different instrumental techniques are presented with the purpose of demonstrating their artistic qualities. The quality of uniformity currently dominates the aesthetic assessment in scientific practice and is discussed in relation to the classical appreciation of the interplay between symmetry and asymmetry in arts. It is argued that scientific and artistic qualities have converged and inspired each other throughout millennia. With scientific discoveries and inventions enriching the world of communication, broadening the space for artistic creativity and making artistic products more accessible than ever, science inevitably influences artistic creativity. On the other hand, the importance of aesthetic principles …

Go to article

Open Ocean Dms Air/Sea Fluxes Over The Eastern South Pacific Ocean, C. A. Marandino, Warren J. De Bruyn, S. D. Miller, E. S. Saltzman Jan 2009

Open Ocean Dms Air/Sea Fluxes Over The Eastern South Pacific Ocean, C. A. Marandino, Warren J. De Bruyn, S. D. Miller, E. S. Saltzman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Air/sea fluxes of dimethylsulfide (DMS) were measured by eddy correlation over the Eastern South Pacific Ocean during January 2006. The cruise track extended from Manzanillo, Mexico, along 110 degrees W, to Punta Arenas, Chile. Bulk air and surface ocean DMS levels were also measured and gas transfer coefficients (k(DMS)) were computed. Air and seawater DMS measurements were made using chemical ionization mass spectrometry (API-CIMS) and a gas/liquid membrane equilibrator. Mean surface seawater DMS concentrations were 3.8 +/- 2.2 nM and atmospheric mixing ratios were 340 +/- 370 ppt. The air/sea flux of DMS was uniformly out of the ocean, with …

Go to article

A Chemical Ionization Mass Spectrometer For Continuous Underway Shipboard Analysis Of Dimethylsulfide In Near-Surface Seawater, Eric S. Saltzman, Warren J. De Bruyn, M. J. Lawler, Christa Marandino, C. A. Mccormick Jan 2009

A Chemical Ionization Mass Spectrometer For Continuous Underway Shipboard Analysis Of Dimethylsulfide In Near-Surface Seawater, Eric S. Saltzman, Warren J. De Bruyn, M. J. Lawler, Christa Marandino, C. A. Mccormick

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

A compact, low-cost atmospheric pressure, chemical ionization mass spectrometer ('mini-CIMS') has been developed for continuous underway shipboard measurements of dimethylsulfide (DMS) in seawater. The instrument was used to analyze DMS in air equilibrated with flowing seawater across a porous Teflon membrane equilibrator. The equilibrated gas stream was diluted with air containing an isotopically-labeled internal standard. DMS is ionized at atmospheric pressure via proton transfer from water vapor, then declustered, mass filtered via quadrupole mass spectrometry, and detected with an electron multiplier. The instrument described here is based on a low-cost residual gas analyzer (Stanford Research Systems), which has been modified …

Go to article