5. How can I spin a liquid or semi-liquid in a rotor without leaks?
First some liquids can be very challenging to spin without leaks and there will be a limit for most methods to the speed that can be achieved before leaks occur. The Doty MAS sealing cells for XC and DI type spinners are the best starting point for these types of samples. We have a variety of sample volumes available and while some volume is always lost in the use of these cells, they will seal for most liquids and keep the sample centered in the RF coil. There are also two material types that will provide a reasonable susceptibility match to most solvents.
Many aqueous samples where sample volume is not limited and B1 homogeneity is not an issue can be spun with normal Kel-f or even Aurum turbine caps up to about 20% of the maximum rated speed for the rotor.
For some of our earlier spinners, O-ring caps are another possible option and will provide a larger sample volume. These caps will usually not stay in very well when used with oily samples.
In some extreme cases in may be necessary to use normal turbine caps and glue them into the rotor with super glue. Boiling the rotor in water afterward will usually cause the glue to release but there is a high probability of damage to the turbine caps, so this should be a last resort used with the expectation of throwing away the caps after use.
