• Home
  • Search Results
  • Hydrophilic interaction chromatography versus reversed phase liquid chromatography coupled to mass spectrometry: effect of electrospray ionization source geometry on sensitivity.

Hydrophilic interaction chromatography versus reversed phase liquid chromatography coupled to mass spectrometry: effect of electrospray ionization source geometry on sensitivity.

Journal of chromatography. A (2014-07-16)
Aurélie Periat, Isabelle Kohler, Aurélie Bugey, Stefan Bieri, François Versace, Christian Staub, Davy Guillarme
ABSTRACT

In this study, the influence of electrospray ionization (ESI) source design on the overall sensitivity achieved in hydrophilic interaction chromatography (HILIC) and reversed phase liquid chromatography (RPLC), was investigated. State-of-the-art triple quadrupole mass analyzers from AB Sciex, Agilent Technologies and Waters equipped with brand specific source geometries were tested with various mobile phase pH on 53 pharmaceutical compounds. The design of the ESI source showed to strongly influence the gain in sensitivity that can be achieved in HILIC compared to RPLC mode. The 6460 Triple Quadrupole LC/MS system from Agilent Technologies was particularly affected by mobile phase settings. Indeed, compared to RPLC conditions, 92% of the compounds had an increased signal-to-noise ratio at a flow rate of 300 μL/min in HILIC mode at pH 6, while this percentage dropped to only 7% at 1000 μL/min and pH 3. In contrast, the influence of flow rate and mobile phase pH on the gain in sensitivity between RPLC and HILIC was found very limited with the API 5000 LC/MS/MS system from AB Sciex, as only 15 to 36% of the tested compounds showed an enhanced sensitivity in HILIC mode. With the Xevo TQ-S instrument from Waters, superior sensitivity in HILIC was noticed for 85% of the compounds with optimal conditions (i.e., pH 3 and 1000 μL/min), whereas at sub-optimal conditions (i.e. pH 6 and 300 μL/min), it represented less than 50%. The gain in sensitivity observed in HILIC was found less significant with the recent LC-MS platforms used in this study than for old-generation instruments. Indeed, the improved ESI sources equipping the recent mass analyzers allow for enhanced evaporation efficiency, mainly for RPLC mobile phases containing high proportion of water and this even at high flow rates.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Water, Nuclease-Free Water, for Molecular Biology
Sigma-Aldrich
Ammonium hydroxide solution, ACS reagent, 28.0-30.0% NH3 basis
Sigma-Aldrich
Water, suitable for HPLC
Sigma-Aldrich
Water, sterile-filtered, BioReagent, suitable for cell culture
Sigma-Aldrich
Ammonium hydroxide solution, 28% NH3 in H2O, ≥99.99% trace metals basis
Sigma-Aldrich
Water, deionized
Supelco
Water, suitable for ion chromatography
Sigma-Aldrich
Water, for molecular biology, sterile filtered
Sigma-Aldrich
Water, for embryo transfer, sterile-filtered, BioXtra, suitable for mouse embryo cell culture
Pure Water Density Standard, UKAS ISO/IEC17025 and ISO Guide 34 certified, density: 0.9982 g/mL at 20 °C, density: 0.9970 g/mL at 25 °C
Supelco
Water, for TOC analysis
Supelco
Water, ACS reagent, for ultratrace analysis
Sigma-Aldrich
Ammonium hydroxide solution, BioUltra, ~1 M NH3 in H2O (T)
Sigma-Aldrich
Water, BioPerformance Certified
Sigma-Aldrich
Water, PCR Reagent
Sigma-Aldrich
Reserpine, crystallized, ≥99.0% (HPLC)
Sigma-Aldrich
Water, for cell biology, sterile ultrafiltered
Sigma-Aldrich
Salbutamol
Sigma-Aldrich
Water, ACS reagent
Sigma-Aldrich
(1S,2S)-(+)-Pseudoephedrine, 98%
Sigma-Aldrich
Terfenadine
Sigma-Aldrich
Reserpine
Sigma-Aldrich
Water, tested according to Ph. Eur.
Sigma-Aldrich
E-Toxate Water, endotoxin, free
Sigma-Aldrich
Water, deuterium-depleted, ≤1 ppm (Deuterium oxide)
Supelco
Water, for HPCE, for luminescence, suitable for UV/Vis spectroscopy
Sigma-Aldrich
Tetracaine, ≥98% (TLC)
Supelco
Reserpine Standard for LC-MS, analytical standard, for LC-MS
Supelco
Density Standard 998 kg/m3, H&D Fitzgerald Ltd. Quality
Sigma-Aldrich
Pindolol, ≥98% (TLC), powder