Filtering by Retention Time

The option “filter_by_rt” (-f) can be used to filter out regions of all chromatograms provided as an input. Not only will PyParse remove any peaks in these regions from consideration, but it will also recalculate all peak percentage areas to reflect the fact that this region was removed.

Usage

To use this option, a range (or multiple ranges) should be provided in the form: “[first_retention_time]-[second_retention_time]”

For example, to filter out all peaks between 0 and 0.4 minutes, you would add the following argument:

Filter out a specific range of the chromatogram

-f 0-0.4

An example chromatogram where a specific range was filtered out.

To filter out multiple ranges, input each range separated by a space:

Filter out a multiple ranges of the chromatogram

-f 0-0.4 1.0-1.1

The result of this filtering is that the purity reported by PyParse is higher:

Top) Original purity value for Product1; Bottom) New purity value for Product1

The purpose of this feature is to enable the user to remove solvent peaks (e.g. DMSO, toluene) from consideration. However, it should be noted that this feature should only be used with extreme caution to avoid misrepresenting the results!