UHPLC/UPLC performance

Alternatively, ultraperformance—ultrahigh-performance LC (UPLC— UHPLC) systems have the benefit over conventional LC of increased peak resolution, which may be sufficient to separate some of the analytes of interest from matrix components. The validated method of Badawi et al. [90] is an example of the application of a matched UHPLC—UPLC— tandem MS system to the analysis of oral fluid for DUID purposes. The additional benefits of higher peak sensitivity and the ability to shorten the run time of the analysis offered by UPLC systems make them ideal for DUID testing. To take full advantage of UHPLC—UPLC, fast tandem—MS instruments are required to obtain sufficient data points across such narrow peaks. 

Figure 9.3 shows an impurity separation under conventional pressures with a 5 /mi particle, 2.1 x 150 mm column, and the same separation performed via UPLC using a 2.1 x 50 mm column with 1.7 /im particles. The run time was improved by a factor of six, with overall resolution comparable to that of the original separation on the 5 /an column. The application of UHPLC technology to impurity profile analysis can exert a significant impact on laboratory productivity by achieving a... 

Ultra high performance liquid chromatography (UHPLC) or ultra performance liquid chromatography (UPLC) is a quite novel technique, but it is one of the most popular nowadays, due to the fact that it is much more rapid than conventional LC. UHPLC systems can work at very high pressures and are compatible with stationary phases with particle sizes of around two micrometers or even smaller. Thus, the development of UHPLC methods [69,77, 80] or the conversion of HPLC to UHPLC methods is a current trend, due mainly to the speed of analysis and low solvent use. 

Most frequently, high-pressure liquid chromatography (HPLC) is used in LC-MS work, while more recently ultrahigh-pressure liquid chromatography (UHPLC or ultra performance liquid chromatography, UPLC, as it is termed by one manufacturer) has come into use. For very low saiiple amounts, nanoLC, i.e., capillary LC, can directly be interfaced to nanoESI. 

---