What's the plural form of mass spectrometry? Here's the word you're looking for.
Answer
The noun mass spectrometry can be countable or uncountable.
In more general, commonly used, contexts, the plural form will also be mass spectrometry.
However, in more specific contexts, the plural form can also be mass spectrometries e.g. in reference to various types of mass spectrometries
or a collection of mass spectrometries.