The organic preparative purification and separation steps are followed by the analytical determinations for the characterization and identification of the reaction products. The analyses are usually carried out by separate departments which, beside the NMR and IR techniques, carry out mass spectrometry (MS) tests to determine the structure of molecules arising during the synthesis. However, the chemist doing preparative work can take into account the results generated in this way only during a later synthesis and/or separation. To reduce the loss of time, there has been a growing demand for a technique which is capable of the more accurate characterization of the molecules simultaneously with the separation.
The detection techniques widely used in flash chromatography so far have not been proved to be molecule specific enough, although, during many syntheses, the signals provided by the UV/Vis detectors can be used satisfactorily of the reaction mixture components. The appearance of the miniaturized mass spectrometer accelerates the synthesis work significantly, as the mass selective fraction collection is possible already during the separation. Thus, we can get immediate information concerning the quality of the reaction product.
With the Biotage Isolera flash chromatography instruments the Dalton mass spectrometry detector creates a fully integrated system. The Biotage Spectra software with the touch screen controller provides the setting of the operation parameters and the evaluation of the mass spectra and the UV/Vis Spectra registered during the separation on a unified surface, thus, additional software are not necessary. The fraction collection starts at the control signal provided by the mass detector, thus, the Isolera Dalton flash/MS chromatography system is capable of separating the inactive molecules in the UV/Vis range and identifying the molecules selectively. Due to its small size, the Isolera Dalton flash/MS system can be placed into a fume cupboard with all its accessories. The mass detector has a chip-based electrospray ionization module, a miniaturized quadrupole analyzer and a built-in vacuum pump, thus, it does not need an external vacuum pump for operation. Adequate liquid flow has to be provided for the direct connection of the flash chromatographs and mass spectrometers. In the Biotage Isolera Dalton system the flow connection and the access of the sample into the mass detector is provided by the Nanolink interface, capable of automatic adjustment to the flow rate, developed for this purpose. The Nanolink interface enables the system to use chromatography columns of different type and size, as well as to carry out normal and reverse-phase separation. In order to determine the target weight, it is possible to inject a part of the reaction mixture into the detector with manual injection as a prior step to the separation. In the case of automatic operation, there is a choice between the scan mode and the 4 selected ion-monitoring mode. Thus, fraction collection can be carried out based on the molecule weight, as well as on the combined molecule weight and the UV/Vis signal.
- mass spectrometer: miniaturized quadropol, +/- electrospray ionisation modes
- detection range (mass/charge): m/z 80 – 800
- accuracy: ± m/z 0.5
- sensitivity: 10 pg (s/n=10:1)
- vacuum pump: built-in
- controlled by: Isolera Spektra
- N2 gas pressure: 2-6 bar
- N2 gas consumption: 2.5 l/min
- Isolera Dalton dimensions: 85 x 59 x 62cm, 77 kg.
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Isolera ELSD-1080 light scattering detector is for the detection of non-volatile substances without UV/VIS absorbance or with low absorbance. It has graphic display and multi-function buttons for setting the operation parameters. It can be connected to Isolera systems with analog signal output.
- light source: 480 nm laser diode
- detector: photomultipliertube(PMT)
- evaporating chamber temperature: settable between 10° and 80°C
- nebuliser chamber temperature: settable between 25 – 90 °C
- eluent flow rate 0.2-5 ml/min, with flow split up to 150 ml/min
- for function a supply of auxiliary gas is neccessary (nitrogen with purity better than > 99.5%, 0.9-3.25 l/min, 60-100 psi).
- dimensions: 415x450x200 (HxDxW), 13 kg
Leak detector based on the refractive index change for Isolera Prime and Isolera systems. Its operation can be switched on/off from the software.
3-way injector valve syringe with adaptor for injecting liquid samples.
For fraction collection test tube holders for test tubes of 13×100 mm, 16×150 mm, 18×150 mm, 25×150 mm, also vessel holders for vessels of 120 ml, 240 ml, 480 ml.
DLV (Dry Loading Vessel) kits for solid samples (1-30 g, 10-70 g, 50-500 g) applied on the support. They can be connected directly to columns with luer connector pressure limit: 7 bars.
Column holders (mounted onto the side of the instrument, they provide the vertical placement of the columns) for Biotage SNAP, SNAP Ultra and ZIP flash chromatography columns.
FlashPack holder for standard size syringe type columns, which can be used with Biotage Isolute flash chromatography columns, with other, commercially available columns of the same geometry and with self-loaded columns with the corresponding pistons.