title: Improving the universal response of evaporative light scattering detection by mobile phase compensation.
abstract: Mobile phase compensation, first reported for the charged aerosol detector (CAD), was used as a suitable method to overcome problems related to the mobile phase-dependent response of the evaporative light scattering detector (ELSD). Mobile phase compensation was effectively performed both in the flow injection- and in gradient modes. Without compensation, the response factors of the ELSD for six sulfonamide drugs differed by a factor of two when varying the mobile phase composition between 10 and 90% acetonitrile. This change could be effectively eliminated using the technique of mobile phase compensation, where a secondary pump with a reversed gradient was used to provide the detector with a constant composition of the mobile phase. For identical experimental conditions, the ELSD showed a nearly constant, albeit somewhat reduced, response with compensation. This indicates that under such conditions, the ELSD behaved as a concentration-sensitive detector. The analysis of sulfonamides drugs at 0.05% level using gradient UPLC-ELSD separation with mobile phase compensation is demonstrated.
authors.affiliation: Pfizer Analytical Research Centre, Ghent University, Krijgslaan 281 S4-bis, B-9000 Ghent, Belgium.
authors.forename: André
authors.initials: A
authors.lastname: de Villiers
authors.forename: Tadeusz
authors.initials: T
authors.lastname: Górecki
authors.forename: Frédéric
authors.initials: F
authors.lastname: Lynen
authors.forename: Roman
authors.initials: R
authors.lastname: Szucs
authors.forename: Pat
authors.initials: P
authors.lastname: Sandra
mesh_terms: D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods; D008027:Light; D012542:Scattering, Radiation