Inter-laboratory reproducibility of the LC-ELSD method for the control of composition of sesame oil recently introduced in the Ph. Eur.

Evaporative light-scattering detection (ELSD) is an increasingly important technology for the control of substances for pharmaceutical use. A LC-ELSD method has recently been introduced in the Ph. Eur. monograph for sesame oil, refined to control the composition of triglycerides. A collaborative study was run to assess the reproducibility of the new method and to confirm that it was suitable for pharmacopoeial use.

Evaporative light scattering detection (ELSD): a tool for improved quality control of drug substances.

Thanks to the recent technological advancements, evaporative light-scattering detection (ELSD) is regarded as a valuable alternative to UV detection for liquid chromatographic analysis of substances that do not contain a chromophore. In the field of substances for pharmaceutical use, LC-ELSD appears to be suitable for aminoglycosides, most of which (for ex. gentamicin) are presently controlled in the Ph. Eur. by pulsed amperometric detection. Other substances (ex sugars, triglycerides) presently employing refractometrric detection, could be conveniently analysed by LC-ELSD. ELS detection is regarded as robust and relatively simple, although not particularly sensitive. A key feature of ELSD is that - unlike refractometry - it can operate in gradient mode, thus allowing application of more selective liquid chromatographic methods. ELSD can also be used to set up MS-compatible methods, as the mobile phase constraints are essentially the same. Due to all the above, ELSD is becoming increasingly used in pharmacopoeial methods.