How is a Mass Spectrum Actually Generated?

There is a flash system on the market with built-in mass detection, called Isolera Dalton. It uses pretty cool technology to produce its final mass spectrum,  compiling data from hundreds of individual mass spectra in real time.

Modern flash chromatography instruments are evolving with the built-in capability of determining masses of individual components in the crude mixture, and allowing separation by molecular mass. The technology producing this result is quite astonishing.

In 2013, Biotage released Isolera™ Dalton, increasing the power and versatility of flash purification by introducing a mass detector, allowing purification of compounds on the basis of their mass. During flash purification with Isolera Dalton, m/z values for parent ions of interest can be either entered manually, or automatically detected from a direct injection of the mixture to be purified. Up to four ions can be monitored in this way, with the option to trigger fraction collection by mass.

Direct Injection

Direct injection of sample mixture is an optional part of the purification procedure. The purpose of this procedure is two-fold:

  • The presence of target compounds in a reaction mixture is readily identified in a single step.
  • The mass of the target is entered into the flash method for separation (alternatively, masses can be entered manually).

During this process, a small amount of the solution of interest is slowly injected into the Isolera™ Dalton Nanolink port at a concentration of typically 1 mg/ml. As the solution passes through the system, aliquots of material are sampled into the mass spectrometer and a spectrum is acquired every second. The sampling of the solution is confirmed during the injection by an increase in the total ion count. After the solution has passed through the system, a wash with pure solvent is performed to clean the tubing. At the end of this process, a accumulated mass spectrum is displayed.

One of the most noticeable features is the way in which data from the direct injection process is captured and displayed, and how it compares to data from an analytical mass spectrometer. The Isolera™ Dalton spectrum is in fact accumulated data from all the spectra obtained during the injection. This is to maximize the possibility of seeing the peak of interest – especially important for flash users.

mass-spectrum-scans

Example Study

To illustrate the unique way in which the data is accumulated and displayed, a single mass spectrum from the direct injection procedure was extracted and viewed using Masscape software. You can download the full paper below.

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