Evaporative light scattering detection (ELSD) is rapidly becoming the preferred concentration detection method for liquid chromatography, either as the ideal substitute for, or supplement to, traditional HPLC detectors. ELSDs offer the following key benefits over more conventional UV and RI detectors:
PL Varian's ELSDs are ideal detectors for many compounds, including those with no UV chromophore or widely differing extinction coefficients. When UV detection is used to monitor the separation of equal amounts of aspirin and phenacetin, different responses are recorded due to variable extinction coefficients at 280nm. Clearly, a more uniform response is obtained when ELSD is used.
KEY
1. Aspirin
2. Phenacetin
For the analysis of sugars, UV detection is inappropriate as carbohydrates have no UV chromophore, therefore, for this type of isocratic separation, RI has been commonly used despite its drawbacks. ELSD detection is the perfect alternative to RI detection, providing higher sensitivity and dramatically improved baseline stability.
KEY
1. Stachyose
2. Sucrose
3. Glucose
4. Fructose
5. Sorbitol
As the operational requirements for LC-MS and ELSD are very similar, PL ELSD methods can be directly transferred to MS, saving valuable LC-MS development time. PL's evaporative light scattering detectors can be used in parallel with any standard LC-MS system to obtain concentration information for all compounds, irrespective of whether or not they are UV active.
KEY
1. Verapamil
2. Diazepam
