UV-Visible Spectroscopy in the analysis of sodium chloride in potato chips
NaCl solution as you know is almost transparent in the VIS region, UV-VIS spectroscopy can be used to determinate concentration of soluble salt see J. Phys. Chem. A 2008, 112, 2242-2247 however UV part of the spectra is used instead of VIS part, so this does not fit the restrictions of your question.

Surely AAS has a greater sensibility and so is the best technique to use in this case.