@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 {3000,
	title = {BIOACCUMULATION AND EXCRETION OF ARSENIC COMPOUNDS BY A MARINE UNICELLULAR ALGA, POLYPHYSA-PENICULUS},
	journal = {Applied Organometallic Chemistry},
	volume = {8},
	number = {4},
	year = {1994},
	note = {ISI Document Delivery No.: PD643Times Cited: 27Cited Reference Count: 43},
	month = {Jul},
	pages = {313-324},
	type = {Article},
	abstract = {Polyphysa peniculus was grown in artificial sea-water in the presence of arsenate, arsenite, monomethylarsonate and dimethylarsinic acid. The separation and identification of some of the arsenic species produced in the cells as well as in the growth medium were achieved by using hydride generation-gas chromatography-atomic absorption spectrometry methodology. Arsenite and dimethylarsinate were detected following incubation with arsenate. When the alga was treated with arsenite, dimethylarsinate was the major metabolite in the cells and in the growth medium; trace amounts of monomethylarsonate were also detected in the cells. With monomethylarsonate as a substrate, the metabolite is dimethylarsinate. Polyphysa peniculus did not metabolize dimethylarsinic acid when it was used as a substrate. Significant amounts of more complex arsenic species, such as arsenosugars, were not observed in the cells or medium on the evidence of flow injection-microwave digestion-hydride generation-atomic absorption spectrometry methodology. Transfer of the exposed cells to fresh medium caused release of most cell-associated arsenicals to the surrounding environment.},
	keywords = {ARSENIC BIOACCUMULATION, ARSENIC METYLATION, arsenic species, ARSENIC UPTAKE, COMPOUNDS, CONTAINING RIBOFURANOSIDES, ENVIRONMENT, IDENTIFICATION, KELP ECKLONIA-RADIATA, METABOLISM, METHYLATION, NON-REDUCIBLE ARSENICALS, ORGANOARSENIC, PHYTOPLANKTON, POLYPHYSA-PENICULUS, RIVER BEAULIEU, SPECIATION},
	isbn = {0268-2605},
	url = {<Go to ISI>://A1994PD64300004},
	author = {Cullen, W. R. and Harrison, L. G. and Li, H. and Hewitt, G.}
}
