Review: "UHPLC - Why all the hype?

<p><a href="http://forums.waters.com/clearspace_community/docs/DOC-1009">"UHPLC - Why all the hype?"</a></p><p>Houghton R, Grace P.</p><p><em>Chromatography Today.</em></p><p>2008 Feb:5-7.</p><p style="height: 8pt"/><p>The authors in the article describe how they have evaluated and implemented ACQUITY UPLC in their organization as well as critically reviewing the benefits UPLC brings to the chromatographic process. HFL are a contract research organization based near Newmarket UK, with LC/MS/MS as the primary analytical platform for their business. As such any improvements in performance of the LC system could increase the productivity of the business and data quality returned to the customers.</p><p style="height: 8pt"/><p>The authors had previously tried techniques such as capillary electrophoresis, turbulent flow LC and monoliths without a major impact. Thus when the "new" technique of UPLC was suggested to them, with claims of speed sensitivity and resolution benefits they were naturally sceptical. These concerns were quickly dispelled, with run times reduced by a factor of 5 and sensitivity in the MS increased by a factor of 3. Two years and thousands of samples later the authors regard UPLC as the "the biggest step forward in main-stream chromatography in the last 25 years".</p><p style="height: 8pt"/><p>To illustrate these benefits the give several examples of how the implementation of UPLC technology has improved the LC/MS performance reducing matrix effects, improving throughput and lowering limits of detection. In a simple example they demonstrate for the analysis of ciprofloxacin (antibiotic) in human plasma a UPLC assay was developed in less than 30 minutes with 6 times the sensitivity and reducing the analysis time from 4 minutes to 0.8 minutes. Perhaps the most striking example of the analytical benefits this increased UPLC is in the reduction of matrix effects. The authors describe how they faced a taxing situation, after developing and validating an assay for ursodexycholic acid in human plasma, the real samples contained elevated levels of an interfering isomeric interference, resulting a need for a new assay. As the authors state with sample awaiting analysis ‘a rapid solution had to be found". By exploiting the ability of the ACQUITY UPLC system to operate at pressures up to 15,000 psi (1000bar) a 15 cm column containing 1.7µm packing material could be used and a new assay was quickly developed, validated and the samples analysed. The extra resolution of the ACQUITY system was used for a sample limited epidemiological study to include data on an analyte (matairesinol) which could not previously be quantified by HPLC/MS due interference peaks in the baseline.</p><p style="height: 8pt"/><p>Its not just in the acquiring the data that the authors have seen benefits of ACQUITY UPLC /MS analysis. The data processing times were also significantly reduced; The "Sharper peaks produced by UPLC resulted in less user intervention" state the authors. Methods development was also simplified compared to HPLC "in most cases it was faster" the authors suggest it's faster to just redevelop the UPLC/MS method rather than transfer an existing HPLC method. Again comparing to current HPLC methods the authors found, that with "good housekeep procedures" column lifetimes, were comparable >2000 injections with improved precision and accuracy.</p><p style="height: 8pt"/><p>When examining the UPLC technology they point to the combination of the sub 2 µm packing material, with a ultra - high pressure low dispersion system was the key to the observed results. They state that conventional HPLC systems return only 65% of the columns performance capabilities whilst UPLC delivers 95%. In conclusion state that UPLC delivers shorter run times, greater instrument utilization and enhanced chromatographic performance "perhaps even eliminating matrix effects" they point to the possibility of GC like performance from this technology in the...