Premium
Ionization efficiency ladders as tools for choosing ionization mode and solvent in liquid chromatography/mass spectrometry
Author(s) -
Rebane Riin,
Kruve Anneli,
Liigand Jaanus,
Liigand Piia,
Gornischeff Artur,
Leito Ivo
Publication year - 2019
Publication title -
rapid communications in mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.528
H-Index - 136
eISSN - 1097-0231
pISSN - 0951-4198
DOI - 10.1002/rcm.8545
Subject(s) - atmospheric pressure chemical ionization , chemistry , direct electron ionization liquid chromatography–mass spectrometry interface , mass spectrometry , electrospray ionization , chromatography , ion source , ionization , chemical ionization , analytical chemistry (journal) , desorption electrospray ionization , ion suppression in liquid chromatography–mass spectrometry , analyte , liquid chromatography–mass spectrometry , acetonitrile , ion , organic chemistry
Rationale The choice of mobile phase components and optimal ion source, mainly electrospray ionization (ESI) or atmospheric pressure chemical ionization (APCI), is a crucial part in liquid chromatography/mass spectrometry (LC/MS) method development to achieve higher sensitivity and lower detection limits. In this study we demonstrate how to rigorously solve these questions by using ionization efficiency scales. Methods Four ionization efficiency scales are used: recorded with both APCI and ESI sources and using both methanol‐ and acetonitrile‐containing mobile phases. Each scale contains altogether more than 50 compounds. In addition, measurements with a chromatographic column were also performed. Results We observed a correlation between calibration graph slopes under LC conditions and log IE values in ESI (but not APCI) thereby validating the use of log IE values for choosing the ion source. Most of the studied compounds preferred ESI as an ion source and methanol as mobile organic phase. APCI remains the ion source of choice for polycyclic aromatic hydrocarbons. For APCI, both acetonitrile and methanol provide similar ionization efficiencies with few exceptions. Conclusions Overall the results of this work give a concise guideline for practitioners in choosing an ion source for LC/MS analysis on the basis of the chemical nature of the analytes.