Yep i do Salters and I did the concentration of aspirin in tablets too
It's highly recommended by the exam board as it gives you access to the higher marks but does not involve an overly complicated method
I also synthesised my own aspirin (rather more complicated but still doable) and tested the purity of that too
I did titrations, iron III chloride solution, TLC plates... that sorta thing
If you want to look over my stuff then after Aug 18th when i get my grade i'll happily send you some stuff