Don't pitch your ink stained coat.
Depending on the kind of ink, it may be salvageable.
Soak it in isopropyl alcohol (90% if you can get it. 70% will do the trick.) I mean, really soak. Like put it in a 1 gallon size ziplock and pour enough alcohol in to completely saturate it. and still have some fluid sloshing around. Let it soak for an hour or two, then rinse it out. It should draw out a lot of the ink. If it doesn't , then never mind, this isn't going to work. If it does, great! Repeat. More than once if necessary. Don't dry it out in between rinsings. Isopropyl is like $1/liter, so don't be afraid to use plenty of it. After 2-3 soaks in alcohol, do one with vinegar, hydrogen peroxide, or oxyclean. (Don't mix! Always rinse well with water in between each flush with a different agent!)
It may cost $10 or so for supplies, and take 2-3 days of intermittent effort, but you can get even large, saturated ink blotches out of white fabrics. When I was a nursing student, I had no money for new uniforms and had to use this method a few times.
Also, when you get a new or freshly salvaged white coat, get some waterproofing spray from an outdoor supply store... the kind you use to waterproof tents, boots, and other rugged outdoorswear. Follow the instructions and waterproof your coat. (I recommend doing this outdoors, so that you don't get the overspray in places you don't want it. A white coat that repels body fluids, and which has a barrier to keep ink from sinking into the fibers is a coat to be treasured.
