Cooling Process Cryogenic Equipment

Two of the process steps require cryogenic temperatures (<-70 °C), necessitating specialized equipment and energy-intensive cooling. Furthermore, three other steps require cooling to —30 to 0 °C. 

Probes usually have variable temperature control to run experiments at temperatures selected by the analyst. Cryogenically cooled probes can improve the resolution of a system, so that a 600 MHz spectrometer equipped with such a probe can provide resolution equivalent to a 700-800 MHz instrument. In some systems, samples can be heated up to 80°C. New probe designs with flowthrough sample holders are commercially available for use in coupled HPLC-NMR instruments, HPLC-NMR-MS instruments, and online process control analyzers. These hyphenated instruments and process instruments are discussed under applications later in the chapter. 

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