HPLC is a university year two topic. It is
not easy to explain the concepts to Sec 2 students.
BTW, do you have any research mentors to
guide you into doing the experiments? If not, then this project is
unsuitable for Sec 2 to do it.
A very mickey mouse way of explaining it is that you have a
mixture, you pass the mixture into a HPLC,
then the mixture will be separated into its various components by
using some solvent, then you pass maybe one of the component into a
mass sorter (mass spectrometer) and you find out how many % of the
weight in the mixture is due to the weight of MSG. You get some computer print-outs.
There are many variations and technical details in HPLC.
Regards.