Chromatography data processing

• Reliable identification of compounds using chromatographic analysis techniques usually requires a substantial amount of effort and attention. Variations in retention time, caused by various degrees of variation in chromatographic conditions, can have the effect of shifting peaks in each chromatogram. By using wide identification windows this can usually be dealt with, but not always. By choosing narrow windows, the chance of misidentifying can be reduced, at the risk of also missing peaks which should have been identified.

  The task of finding accurate settings is often very time-consuming. Success is not guaranteed, often some doubt remains about the window choices. In practical use, the dilemma remains of either finding optimum settings for a specific set of results, or proceeding with lower reliability to process large amounts of data. This dilemma can be avoided.

• MetaChrom is a powerful software solution which offers an optimal form of processing.

  Large numbers of analyses can be processed, even with several critically resolved pairs. The quality of identification and quantification can actually be improved with a larger number of measurements.

  This is made possible because of a new concept; the Frequentogram provides insight in the distribution of all measured retention times in an entire dataset and enables you to optimize identification settings. A powerful algorithm is applied to compensate for drifts in retention time, controlled by a small number of parameters. When adjusting these parameters, (re-) identification of all peaks is performed in a matter of seconds, even with tens of compounds in hundreds of analyses. The result of this identification process, which includes quality indicators, can be presented on the screen in a variety of graphical formats and can be inspected in more detail where needed.

• Quantification of compounds, both individual and grouped by response factor, is based on curve-fits as calculated by MetaChrom. Here too, the adjustment of parameters will cause immediate recalculation of the affected quantification results. Again, several quality measures can provide clues about problems with specific measurements and aid in dealing with individual situations.

  Along with an indication of the reliability of each analysis, the quality measures are also suitable to evaluate the stability of the analytical systems used. Optimization can be iterated to gradually generate more and better results; once acceptable, all final results can be exported in a single step.

• MetaChrom can process analysis results from any standard integrator or chromatography package and can use a variety of detector response curves. Results from more than one source can be combined as a multi-system analysis. Any standard spreadsheet package can be used for the input of identification and quantification parameters.

  A project document is used to store all settings related to the processing of a specific set of data files. This file also contains information about the origin of measurment data. All major decision are tracked in an ‘audit trail’ and are uniquely identified by a signature tag which allows you to trace back to each of these decisions. Each exported data file can also be tagged with such a signature, to conform to Good Laboratory Practice (GLP) guidelines.

  Detailed reports of all analysis results, as well as their quality measures, can be exported in a variety of file formats, for use in spreadsheets, databases, statistical- and word-processing applications.

• Since the first version of MetaChrom, which was released in 1990 by Meta Four Software, many customers have selected this system. These include researchers from companies such as RIVM (Bilthoven, The Netherlands), JRC (Ispra, Italy), EPA (RTP, USA) and Battelle (Columbus, USA).

  It has been shown that the productivity is enhanced to such a degree, that hundreds of analyses with tens of compounds can be processed by one chromatographer, often in just a matter of hours. Also, in large projects a substantial set (10-20%) of all identifications in complex samples will succeed better with MetaChrom than can be achieved by conventional chromatography software.

For more information, look at the product sheet.