ELSD触发制备—适用于4.6mm-75mm内径色谱柱的分流方案

Abstract 

This Technical Overview describes a solution to monitor and trigger the collection of preparative samples with the Agilent 1260 Infinity Evaporative Light Scattering Detector (ELSD) using a flow splitter. The Agilent 1260 Infinity ELSD is the detector of choice to monitor low UV-absorbing compounds or compounds with no UV-chromophore. Furthermore, this detection method is able to detect all compounds less volatile than the mobile phase, suitable for the detection of small molecule mixtures. 

A drug-like sample mixture has been purified on an Agilent 1260 Infinity Preparative-scale Purification System by triggering the fraction collection with the Agilent 1260 Infinity ELSD. 99 % of purity and 91 % recovery were achieved.

Introduction 

For complex mixtures, natural products, small molecules, or low-UV-wavelength absorbing compounds, using an ELSD is a perfect solution to achieve reliable sample purification. In addition, this detection method allows adjustments of the different detector parameters such as light intensity, nebulizer temperature, gas flow, and temperature. This flexibility enhances the detector capabilities for preparative-specific applications. For example, in preparative liquid chromatography, the sensitivity of the detection method is an important criterium. By reducing or increasing the light intensity of the ELSD, the sensitivity of the detector can be adjusted to the concentration used for the sample purification. 

In peptide synthesis, the remaining nonaromatic amino acids cannot be monitored by a conventional UV-detector, thereby requiring an ELSD or a MSD. The Agilent 1260 Infinity ELSD provides the simplest way to monitor or trigger the collection of the target compound without risk of collecting impurities with the collected target peptide fractions1 . Another example is DMSO peak removal by increasing the gas flow or temperature to monitor the compounds underneath of the DMSO signal. 

This Technical Overview describes an easy way to split the preparative flow after UV-detection to the ELSD and fraction collector for fraction collection triggering of the sample mixture. Collecting the sample mixture can be done by ELSD or UV peak-based collection methods (Figure 1). 

The split is achieved by flow restrictions generated by system backpressure after the column. Thus, for different flow rate ranges and systems, different splitter kits are required. Table 1 gives the different splitter configurations depending on purification scales and systems.

Conclusion 

This Technical Overview shows how a simple splitter solution was used to enhance the detection method for the purification of small molecules or non-UV chromphores with the combination of the Agilent 1260 Infinity Preparatives-scale Purification System with the Agilent 1260 Infinity ELSD. 

The splitter kits were high reproducible concerning the purification results. Collection of the target compound was triggered by the ELSD, leading to a recovery of 91 %, and a purity of 99 %.