I have a fractional distillation setup. I would like to purify a small mixture ($\pu{\approx 100-150 mL}$) of high boiling point compounds (between $200$ and $\pu{300^\circ C}$). The one that interests me has a b.p. of $80\rm~^\circ C$ at $\pu{13 mmHg}$. I don't know what this mixture is composed of.
Now the tricky part and the one that give me the most headaches is the vacuum pump. I need one that has enough vacuum power to be able to distill at $\pu{13 mmHg}$ and one that is not expensive too.
I also need a system to be able to monitor and control the vacuum pressure too, so the vacuum pressure remains constant.
I figured that a diaphragm pump is not suitable since the ones that have that kind of vacuum power are way more expensive than rotatory vane pumps. Can anyone help?