In a recipe we might have: "Flour: 2 cups".
In chemistry, the analog is like: "2 drops of water".
Similarly, In medicine: "Aspirin: 80mg".
The name of the substance by itself has names like "ingredient", "reagent", "medication". Likewise, the amount can be called "amount" or "dosage".
But I need a name for both together and haven't been able to think of what to call it. Is there a word or phrase that means that?
Perhaps it would be used like this: The third ???? in the recipe is "2 cups flour"
EDIT: A word that is really close is the medical usage of "prescription". For example, "The prescription was for 80mg of aspirin."