|
This spectrometer is suitable to the study of small molecules, proteins that do not require very high-fields and to exploratory work with samples to be analyzed in the 800 MHz spectrometer. Therefore, this spectrometer also performs high resolution liquid NMR spectroscopy (HR-NMR) and high-resolution magic angle spinning NMR spectroscopy (HRMAS-NMR). As a HR-NMR spectrometer the AvanceIII 500 is equipped with a 5 mm QXI-Z C/N/P probe-head and a 10 mm QNP C/N/P probe-head; while working as a HRMAS-NMR spectrometer it is equipped with a 4mm HR MAS Triple H/P/C probe-head.
Time devoted to the National NMR Network: 30%
Description and history of the equipment:
The spectrometer was acquired by the Rede Nacional de RMN (National NMR Network) in November 2006, and its installation completed in December of the same year. The equipment, controlled via Topspin V.2.1 software installed in a PC with the LINUX operating system, comprises a double bay console model AVANCE II+ and a 500 MHz Ultra-Shield Magnet with 54 mm diameter standard bore. The 5 Gauss magnetic field safety line is described by an ellipsoid with a horizontal and vertical radius of 1.3 m and 1.9 m apart from magnetic center, respectively.
Two systems are available for low temperature operation:
1. BCU-05 – a nitrogen gas cooling system (exit gas temperature of ‑20ºC) allowing working temperatures down to 0ºC (approximately);
2. A nitrogen gas cooling system operating by heat exchange with liquid nitrogen allowing working temperatures down to ‑120ºC.
Table of sensivities (signal to noise ratios) for probeheads:
|
