title: Quantitative measurements of small molecule mixtures using laser electrospray mass spectrometry.
abstract: Quantitative measurements of atenolol, tioconazole, tetraethylammonium bromide, and tetrabutylammonium iodide using laser electrospray mass spectrometry (LEMS) reveal monotonic signal response as a function of concentration for single analytes, two- and four-component equimolar mixtures, and two-component variable molarity mixtures. LEMS analyses of single analytes as a function of concentration were linear over ~2.5 orders of magnitude for all four analytes and displayed no sign of saturation. Corresponding electrospray ionization (ESI) measurements displayed a nonmonotonic increase as saturation occurred at higher concentrations. In contrast to the LEMS experiments, the intensity ratios from control experiments using conventional ESI-MS deviated from expected values for the equimolar mixture measurements due to ion suppression of less surface active analytes, particularly in the analysis of the four-component mixture. In the analyses of two-component nonequimolar mixtures, both techniques were able to determine the concentration ratios after adjustment with response factors although conventional ESI-MS was subject to a greater degree of saturation and ion suppression at higher analyte concentrations.
authors: Department of Chemistry and Center for Advanced Photonics Research, Temple University, Philadelphia, Pennsylvania 19122, United States.
authors: Paul M
authors: PM
authors: Flanigan
authors: Johnny J
authors: JJ
authors: Perez
authors: Santosh
authors: S
authors: Karki
authors: Robert J
authors: RJ
authors: Levis
mesh_terms: D001262:Atenolol / Q000737:chemistry; D004867:Equipment Design; D007093:Imidazoles / Q000737:chemistry; D007834:Lasers; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D021241:Spectrometry, Mass, Electrospray Ionization / Q000295:instrumentation* / Q000379:methods; D019789:Tetraethylammonium / Q000737:chemistry
chemical_list: D007093:Imidazoles; D000644:Quaternary Ammonium Compounds; D001262:Atenolol; D019789:Tetraethylammonium; C009405:tetrabutylammonium; C020527:tioconazole