LAUSR

HIGHLIGHTSCharged aerosol detection of S‐lysophosphatidylcholines in phospholipid formulation.HPLC columns were chosen based on the hydrophobic subtraction model for screening.HPLC conditions were selected to give a stability indicating separation.Optimal power function values were different between two systems of identical build.Column effluent only with analytes sent to detector to mitigate response drifts and matrix effects. ABSTRACT A four parameter optimization of a stability indicating method for non‐chromophoric degradation products of 1,2‐distearoyl‐sn‐glycero‐3‐phosphocholine (DSPC), 1‐stearoyl‐sn‐glycero‐3‐phosphocholine and 2‐stearoyl‐sn‐glycero‐3‐phosphocholine was achieved using a reverse phase liquid chromatography‐charged aerosol detection (RPLC‐CAD) technique. Using the hydrophobic subtraction model of selectivity, a core‐shell, polar embedded RPLC column was selected followed by gradient‐temperature optimization, resulting in ideal relative peak placements for a robust, stability indicating separation. The CAD instrument parameters, power function value (PFV) and evaporator temperature were optimized for lysophosphatidylcholines to give UV absorbance detector‐like linearity performance within a defined concentration range. The two lysophosphatidylcholines gave the same response factor in the selected conditions. System specific power function values needed to be set for the two RPLC‐CAD instruments used. A custom flow‐divert profile, sending only a portion of the column effluent to the detector, was necessary to mitigate detector response drifting effects. The importance of the PFV optimization for each instrument of identical build and how to overcome recovery issues brought on by the matrix effects from the lipid–RP stationary phase interaction is reported.