Coupling of capillary electrochromatography to coordination ion spray mass spectrometry, a novel detection method.
Miniaturized separation techniques such as capillary electrochromatography (CEC), pressurized capillary electrochromatography (pCEC) and capillary high performance liquid chromatography (CHPLC) have been coupled to a new detection technique: coordination ion spray mass spectrometry (CIS-MS). Electrospray ionization (ESI) has found widespread applications in mass spectrometry (MS) for the analysis of polar compounds such as peptides or nucleotides. However, for weakly polar or nonpolar substances, ESI-MS yields poor sensitivity since, in the absence of basic or acidic groups, protonation or deprotonation is not possible. CIS is a universal ionization technique capable of detecting these compounds. Through the addition of a central complexing ion, charged coordination compounds are formed, enabling the detection with good sensitivity. Using the coaxial sheath flow interface commonly employed in CE-MS coupling, we were able to separate and detect various important natural compounds such as unsaturated fatty acid methyl esters, vitamins D2 and D3, and four different estrogens. A central ion solution of 100 microg/mL AgNO3 in water was used as sheath flow liquid, resulting in the formation of positively charged coordination compounds.
Rentel
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University of Tübingen, Research Center of Nucleic Acid and Peptide Chemistry, Institute of Organic Chemistry, Germany.
Gfrörer
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Bayer
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D002762:Cholecalciferol / Q000032:analysis; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D019075:Electrophoresis, Capillary / Q000379:methods*; D004872:Ergocalciferols / Q000032:analysis; D004967:Estrogens / Q000032:analysis; D005229:Fatty Acids, Monounsaturated / Q000032:analysis; D005231:Fatty Acids, Unsaturated / Q000032:analysis; D013058:Mass Spectrometry / Q000379:methods*
D004872:Ergocalciferols; D004967:Estrogens; D005229:Fatty Acids, Monounsaturated; D005231:Fatty Acids, Unsaturated; D002762:Cholecalciferol; C068012:methyl palmitoleate