BACKGROUND

Field of the Disclosure

The disclosure generally relates to research tool and analytical instruments more particularly to instruments utilized in performing magic angle spinning nuclear mass resolution spectroscopy (MAS NMR).

Background Information

When performing MAS NMR in situ sample analysis on a wide variety of specimens has been hampered by an inability to maintain samples under vacuum and at low pressures. In addition, there is difficulty in being able to load specimens under low pressure and perform analysis of them under higher pressures or temperatures. The existing devices for performing MAS NMR simply lack have proven to have various faults and failings in this regard. While a variety of attempts have been made, there are presently no commercially available devices that overcome these failings.

In response to this need a device was created with the intent to fill the gaps left in the prior art and provide a solution for advancing the technology. The present disclosure provides a description of a device that has the capability of maintaining seal under vacuum and enables the preparation of samples at high or low pressures which is an advancement over complementary technologies (i.e. U.S. Pat. Nos. 8,692,548 and 9,835,698). The chamber may also be externally heated (e.g. via hot plate and/or heating tape) for enhanced control over the temperature and pressure of sample preparation. Gases can also be introduced through any of the inlets/outlets through a flow-style manifold, high pressure manifold, or vacuum manifold system. These features provide a substantial advantages over the art in the field.

Additional advantages and novel features of the present disclosure will be set forth as follows and will be readily apparent from the descriptions and demonstrations set forth herein. Accordingly, the following descriptions of the present disclosure should be seen as illustrative of the disclosure and not as limiting in any way.

SUMMARY

The present description provides a description of a sample chamber holder for MAS-NMR capable of operating at both low and high pressures. In one example the sample chamber holder is made up of a sample holder body defining a sample chamber therein, a connector configured to operatively statically hold an in situ rotor within the sample chamber; a coupler configured to operatively connect the sampler holder body to a magnetically coupled rotation member. The magnetically coupled rotation member is configured to engage and rotate a sealing cap from an NMR rotor in such a way so as to allow an NMR cap to be alternatively opened or sealed in-situ while the NMR rotor remains statically positioned in an NMR device.

In one example, the magnetically coupled rotation member includes a magnetically-coupled driver with a cylindrical magnet that maintains a constant preselected pressure within the sample chamber. In another arrangement the sample chamber holder includes at least one additional set of magnets positioned around an outer circumference of the chamber. Preferably, these magnets are placed symmetrically around the outer circumference of the chamber. The positioning of these magnets is intended so that when outside magnet sets are manually rotated, an induced magnetic force inside the chamber makes an internal magnet rotate.

In some application the sample holder chamber is made up of an upper and a lower chamber bodies. Preferably, the lower body is configured to connect with a rotor holder and defines a void space for the gas atmosphere. The upper body is configured to connect to the lower body, preferably in a sealing connection. Viewing windows defined within the chamber body (upper or lower) are positioned and configured to enable observation of an NMR rotor cap while the NMR rotor cap is opened or closed.

The rotor holder is a stage that slides into the lower chamber body to hold the NMR rotor in place during cap manipulation and sample treatment. A securing mechanism, in one embodiment a number if set screws, secure the rotor holder in place.

The upper body of the chamber can be configured to define at least one entry port that enables passage of materials into and out of the chamber. Depending upon the needs of the user a number of items can be connected to these ports including pressure relief valves, thermocouples, gas flow manifolds, liquid inputs or other desired items. The upper body also defines a threaded hole adapted to allow passage for a cap screw-driver mechanism. Which allows access and manipulation of the NMR cap. A bit piece configured to fit and lock on to an NMR drive shaft may also be present.

In use, the NMR rotor is placed within the sample chamber holder and the chamber is sealed. Manipulating the gas composition (such as by purging, flowing, vacuum application, or pressurizing) can then take place and the NMR rotor may be unscrewed within the chamber by the magnetically-coupled cap screwdriver to allow the rotor interior to equilibrate with the chamber gas composition. This enables performing MAS NMR at high or low pressure conditions (e.g. 2,000 psig) or the maximum rating for internal pressure of the NMR rotor. This ability to maintain sealing under vacuum and prepare samples at low pressures and test them at a higher pressure is an advancement over complementary technologies. In addition to enabling variations in pressure, the chamber may also be externally heated (e.g. via hot plate and/or heating tape) for enhanced control over the temperature as well as pressure of the sample. The ability to introduce or remove gases provides additional advantages.

Various advantages and novel features of the present disclosure are described herein and will become further readily apparent to those skilled in this art from the following detailed description. In the preceding and following descriptions I have shown and described only the preferred embodiment of the disclosure, by way of illustration of the best mode contemplated for carrying out the disclosure. As will be realized, the disclosure is capable of modification in various respects without departing from the disclosure. Accordingly, the drawings and description of the preferred embodiment set forth hereafter are to be regarded as illustrative in nature, and not as restrictive.

