@article {724,
	title = {Characterization of copper-complexing ligands in seawater using immobilized copper(Il)-ion affinity chromatography and electrospray ionization mass spectrometry},
	journal = {Marine Chemistry},
	volume = {83},
	number = {1-2},
	year = {2003},
	note = {ISI Document Delivery No.: 743RZTimes Cited: 13Cited Reference Count: 44Ocean Sciences Meeting 2002FEB 11-15, 2002HONOLULU, HAWAII},
	month = {Oct},
	pages = {47-58},
	type = {Proceedings Paper},
	abstract = {Electrochemical studies show that copper and other bioactive trace metals are associated almost exclusively with dissolved organic ligands in surface seawater. Some of these ligands may be released by photosynthetic marine organisms to control metal uptake. However, new analytical approaches are needed to determine the chemical composition and ecological significance of these compounds. We have combined immobilized metal-ion affinity chromatography (IMAC) with electrospray ionization mass spectrometry (ESI-MS) to selectively extract and characterize copper-complexing ligands in seawater. Samples taken from British Columbia coastal waters were filtered through mixed cellulose membranes (0.45 mum) using nitrogen overpressure. Compounds with an affinity for copper were then extracted using Cu(II)-IMAC and eluted in acidified seawater. The eluant was monitored using UV absorption (255 nm), which showed that IMAC extracts from river and surface waters contained the highest concentrations of U-V-absorbing organic matter. Fractions were collected and analyzed by flow-injection (FI) negative ion ESI-MS using a custom made XAD-16 column, which gave 82\% recovery and a detection limit of 1.6 pmol for salicylic acid in acidified seawater. Low-molecular-weight compounds containing nitrogen were detected in the IMAC extracts of highest UV absorbance. These compounds followed an elution profile similar to the corresponding UV chromatogram. Measured masses of 265 and 259 Da are consistent with peptides containing, respectively, one thiol and two primary amino groups, characteristics associated with copper-complexing ligands detected in marine algal cultures and surface seawater using other methods. However, the absence of positive ions under experimental conditions suggests that the extracted compounds are predominantly acidic, and may therefore be hydroxamic acids or other nitrogen-containing compounds. The use of alternative resins and FI solvents to improve recovery, increase ionization efficiency, and permit structural (MS/MS) analysis of compounds extracted by IMAC is now being investigated. (C) 2003 Elsevier B.V All rights reserved.},
	keywords = {CHROMATOGRAPHY, COMPLEXATION, CU, DISSOLVED COPPER, electrospray ionization, ESTUARINE WATER, iron, LIGANDS, marine environment, MARINE-BACTERIA, MASS SPECTROMETRY, OCEAN, organic compounds, ORGANIC-LIGANDS, PHYTOPLANKTON, SPECIATION, stress},
	isbn = {0304-4203},
	url = {<Go to ISI>://000186588500006},
	author = {Ross, A. R. S. and Ikonomou, M. G. and Orians, K. J.}
}
@article {3431,
	title = {STRUCTURAL DETAILS FOR THE CU(110)-C(6X2)-O SURFACE DETERMINED BY TENSOR LEED},
	journal = {Surface Science},
	volume = {339},
	number = {1-2},
	year = {1995},
	note = {ISI Document Delivery No.: RV213Times Cited: 18Cited Reference Count: 28},
	month = {Sep},
	pages = {151-158},
	type = {Article},
	abstract = {A tenser LEED analysis has been made for the Cu(110)-c(6 x 2)-O surface structure using intensity versus energy curves measured for 13 diffracted beams at normal incidence. A good level of correspondence between experimental and calculated intensities has been reached (R(p) = 0.271) for the model type (2/3 monolayer coverage of O) proposed for this surface by Feidenhans{\textquoteright}l et al. This analysis provides direct information on the structural details, and it is indicated that they support the view that the driving force for this structure relates to sufficient O being incorporated in order to stabilize the surface as a modified (211) plane of bulk Cu2O. This structure is composed of double-stranded chains built from 12-membered rings formed by alternating O and Cu atoms. The chains are flattened on the surface, and alternating chains are laterally displaced by half a repeat unit compared with the bulk (211) plane. However, the three-atom O-Cu-O fragments essentially maintain their bulk form in the surface structure. The average O-Cu bond length in Cu(110)-c(6 X 2)-O is indicated to equal 1.90 Angstrom, in exact agreement with the values determined for the half monolayer structures formed by O on Cu(110) and Cu(100).},
	keywords = {copper, CRYSTAL SURFACES, CU, CU(110), ENERGY-ELECTRON-DIFFRACTION, LOW ENERGY ELECTION DIFFRACTION (LEED), LOW INDEX SINGLE, OXYGEN, OXYGEN-CHEMISORPTION, SURFACE RELAXATION AND RECONSTRUCTION, X-RAY-DIFFRACTION},
	isbn = {0039-6028},
	url = {<Go to ISI>://A1995RV21300017},
	author = {Liu, W. and Wong, K. C. and Mitchell, K. A. R.}
}
