So I will reply to myself on this topic, in case someone is interested.
It turns out that the “MCR” technic is a NMF technic performed most of the time using an ALS algorithm, but with specific conditions: closure (sum of the component fractions = 1), uni-modality (components vary in a logical way along a chemical profil, for instance), and of course non-negativity.
So it is quite easy to use Julia NMF algorithm to implement such chemometric technic.
A good paper to read about that is
de Juan, A., and R. Tauler (2006), Multivariate Curve Resolution (MCR) from 2000: Progress in Concepts and Applications, Critical Reviews in Analytical Chemistry, 36(3–4), 163–176, doi:10.1080/10408340600970005.
Best,
C.