Maria wiped (at) her purple cheek powder. It didn't come out.
What's the difference between the two?
Both ways give the same information and have the same meaning, as in this example:
In the example 1 "at" is pointing to the "tear", the only preposition used to give a location in the phrase.
Now in this example it would sound strange to use "wiped at", as the preposition "from" is already being used to point a location, the eye.
So I'd just be careful about the second example, check if a preposition pointing a place is already being used in the clause, in this case don't use wiped at.
If you want more examples you can find them here: Concordander