Effect of experimental parameters on the ESI FT-ICR mass spectrum of fulvic acid

被引:144
作者
Brown, TL [1 ]
Rice, JA [1 ]
机构
[1] S Dakota State Univ, Dept Chem & Biochem, Brookings, SD 57007 USA
关键词
D O I
10.1021/ac9902087
中图分类号
O65 [分析化学];
学科分类号
070302 ; 081704 ;
摘要
Fulvic acid (FA) is a heterogeneous mixture of organic macromolecules found in the waters, soils, and sediments of the earth's surface. The ability of electrospray ionization (ESI) to effectively transfer large ions from the solution phase to the gas phase and the coupling of ESI to the high-mass-resolution capabilities of Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) provide a potential method for the mass spectrometric analysis of FA. Positive- and negative-ion ESI FT-ICR MS analyses of four reference international Humic Substances Society FAs were performed. The spray solution composition was found to have a dramatic effect on the ion distributions, with high-mass aggregates (m/z -2000-4000) being formed in less polar spray solutions. Positive-ion spectra for each FA obtained under optimum conditions resulted in number-average molecular weights ranging from 1700 to 1900. The mass spectra were extremely complex, with ion distributions on the order of m/z similar to 500-3000. The presence of more than one ion at each nominal mass was routinely observed. Negative-ion ESI analysis of the FA samples resulted in the observation of multiply charged ions whose distributions could be affected by the acidification of the spray solution. Solution parameters which have been reported to affect molecular weight distributions of FA such as pH, ionic strength, and concentration of multivalent cations were found to have little or no effect on the observed m/z distributions.
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页码:384 / 390
页数:7
相关论文
共 49 条
[1]   MOLECULAR-WEIGHT OF AQUATIC FULVIC-ACIDS BY VAPOR-PRESSURE OSMOMETRY [J].
AIKEN, GR ;
MALCOLM, RL .
GEOCHIMICA ET COSMOCHIMICA ACTA, 1987, 51 (08) :2177-2184
[2]  
AVERETT RC, 1989, 87557 USGS OFR US GP
[3]  
BARBER M, 1982, ANAL CHEM, V54, pA645
[4]   ION TRAPPING AND MANIPULATION IN A TANDEM TIME-OF-FLIGHT-FOURIER TRANSFORM MASS-SPECTROMETER [J].
BEU, SC ;
LAUDE, DA .
INTERNATIONAL JOURNAL OF MASS SPECTROMETRY AND ION PROCESSES, 1991, 104 (02) :109-127
[5]   CHARACTERISTICS OF SOIL ORGANIC-MATTER IN TEMPERATE SOILS BY CURIE-POINT PYROLYSIS-MASS SPECTROMETRY .1. ORGANIC-MATTER VARIATIONS WITH DRAINAGE AND MULL HUMIFICATION IN A-HORIZONS [J].
BRACEWELL, JM ;
ROBERTSON, GW .
JOURNAL OF SOIL SCIENCE, 1984, 35 (04) :549-558
[6]   PREPARATION, HOMOGENIZATION, AND STORAGE OF EARTH STANDARDS USED AND DISTRIBUTED BY THE INTERNATIONAL-HUMIC-SUBSTANCES-SOCIETY [J].
CAMPBELL, WL ;
MALCOLM, MJ .
ORGANIC GEOCHEMISTRY, 1985, 8 (01) :109-109
[7]  
CHOWDHURY SR, 1990, INT J MASS SPECTROM, V78, P37
[8]  
COOPER AR, 1989, DETERMINATION MOL WE, P1
[9]  
Dubach P., 1963, Soils and Fertilizers, V26, P293
[10]  
FELBECK G. T., 1965, ADVANCE AGRON, V17, P327, DOI 10.1016/S0065-2113(08)60417-4