Application note: Quantitation of polar analytes in high organic solvents and enabling large volume injections on ekspertTM MicroLC 200 using Online-Dilution-and-Refocusing (ODR) (AB SCIEX)
Microflow liquid chromatography is becoming a compelling alternative to conventional UHPLC for many analyses due to its potential for higher throughput, low sample consumption and solvent saving. These benefits are realized while maintaining or enhancing sensitivity in comparison to conventional UHPLC.
The injection of a large sample with high organic content, particularly when the sample solvent is stronger than the mobile phase, can result in peak distortion. This phenomenon is exacerbated in the microflow chromatography due to smaller columns and much lower system dead volumes. In high-throughput quantitation, the goal is to minimize sample preparation time, costs and labor without affecting performance.
In many instances this leads to sample prepared in high organic content. Also, some applications targeting higher sensitivity require injection of larger volume, and in some cases the sample has high organic content too.
The polar compound in high organic solvent may appear as split peak “break-through” when analyzed in microLC. This situation may limit the sample injection volume and ultimately result in no gain in LLOQ normally expected from microLC.
This application note demonstrates the utility of online-dilutingand- refocusing configuration (ODR) to analyze high organic samples, and large volume injection with MicroLC, while maintaining chromatography and sensitivity.
