Comparison between charged aerosol detection and light scattering detection for the analysis of Leishmania membrane phospholipids

The performance of charged aerosol detection (CAD) was compared to evaporative light scattering detection (ELSD) for the analysis of Leishmania membrane phospholipid (PL) classes by NP-HPLC. In both methods, a PVA-Sil column was used for the determination of the major Leishmania membrane PLs, phosphatidic acid, phosphatidylglycerol, cardiolipin, phosphatidylinositol, phosphatidylethathanolamine, phosphatidylserine, lysophosphatidylethathanolamine, phosphatidylcholine, sphingomyelin and lysophosphatidylcholine in the same analysis. Although the response of both detection methods can be fitted to a power function, CAD response can also be described by a linear model with determination coefficients (R2) ranging from 0.993 to 0.998 for an injected mass of 30 ng to 20.00 μg. CAD appeared to be directly proportional when a restricted range was used and it was found to be more sensitive at lowest mass range than ELSD. With HPLC-ELSD the limits of detection (LODs) were between 71 and 1195 ng and the limits of quantification (LOQs) were between 215 and 3622 ng. With HPLC-CAD, the LODs were between 15 and 249 ng whereas the limits of quantification (LOQs) were between 45 and 707 ng. The accuracy of the methods ranged from 62.8 to 115.8% and from 58.4 to 110.5% for ELSD and CAD, respectively. The HPLC-CAD method is suitable to assess the influence of miltefosine on the composition of Leishmania membrane phospholipids.