Performance of some evaporative light scattering detectors (ELSD) in the analysis of triglycerides and phospholipids

Three evaporative light scattering detectors (ELSD) have been submitted to a uniform protocol of analysis of triglycerides (TG) from vegetable oils, and of phospholipids (PL) from soy lecithin and pure standards. The three instruments assayed showed different behaviour regarding their repeatability, linearity, sensitivity and detectability. Differences were also noted regarding reliability and assembling performance. The linearity for all the detectors was indicated by regression coefficients (R) greater than 0.98 in the range 0-250 pg TG injected and 0-25 ng for the PL. Their limits of detectability were less than 50 ng for TG and 0.1 ng for PL. All the ELSD instruments showed a sensitivity 200-400 times greater than the refractive index detector (RI).