Accurate and Reliable Fraction Collection Using the LCMS-2020 Single Quadrupole Mass Spectrometer
Mass-directed preparative chromatography provides higher sensitivity and more specificity than traditional UV-based detection. Utilizing patented ultrafast (UF) technology, such as a scanning speed of 15,000 u/sec and a 15 msec polarity switching speed, the single quadrupole LCMS-2020 mass spectrometer delivers more information about your preparative runs, and enables you to collect the right peak. When combined with the Nexera Prep HPLC, you’ll achieve the ultimate in separation performance and productivity.
MS Detection for Correct Peak Collection
To isolate and purify components, chromatographic systems utilize a fraction collector which is dependent on a detector signal to collect peaks when their retention time is not precisely known. Traditionally, a UV signal is monitored at a particular wavelength, and any peak exceeding a predetermined threshold is collected. But many compounds lack strong UV chromophores, and thus produce poor UV signals. Furthermore, UV identification is highly dependent on known retention times.
Mass-directed fractionation offers many benefits and more reliable performance. Mass detection can easily be 100 times more sensitive than UV, but more importantly, in Scan Mode, the mass detector delivers unambiguous molecular information about every peak. Thus, the user can program peak collection based on a specific molecular property – the molecular weight, or more specifically, the mass to charge ratio – to collect the correct peak of interest.
Combine Detector Signals for High Purity Collection
Shimadzu’s new FRC-40 fraction collector has the capability to simultaneously monitor multiple detector signals, and apply logical rules to start and stop collection based on different signals. These signals can come from UV or other common LC detectors as well as a mass spectrometer. Different wavelengths or different m/z values can provide important distinctions in the selection of the correct peak.
In the example below, the m/z value of target component A was used to trigger the start of fraction collection. The m/z signal from closely eluting impurity B was used to stop collection. The application of logical rules, easily accessible to the user through LabSolutions software, makes it possible to collect fractions of very high purity.