Free alcohol

So I’m a casually drinking college student maybe a couple drinks a week And in a student apartment area I found half a bottle of Tito’s on the sidewalk probably left from some trusties. Normally for a Bloody Mary or mule and other drinks I enjoy I use piss cheap vodka and I want to use this free titos but I’m uncertain how to test it’s content to ensure I’m not drinking something else. I tried finding the Total dissolved solids average of vodka since I have a meter and no other idea of how to test it but couldn’t find any data. It smells like Tito’s and tastes the part but if anyone can offer some input on how to ensure the quality I would greatly appreciate not using my liver as the mode of experimentation