Whit only one C-18 column several isomers cannot be resolved. Several of the following papers used two column in series. Best results are obtained on C-30 RP column in respect to C-18. You may take a look at the following papers:
Chauveau-Duriot et al, Simultaneous quantification of carotenoids, retinol, and tocopherols in forages, bovine plasma, and milk: validation of a novel UPLC method. Anal Bioanal Chem. 2010 May;397(2):777-90. doi: 10.1007/s00216-010-3594-y
Franke et al, Simultaneous analysis of circulating 25-hydroxy-vitamin D3, 25-hydroxy-vitamin D2, retinol, tocopherols, carotenoids, and oxidized and reduced coenzyme Q10 by high performance liquid chromatography with photo diode-array detection using C18 and C30 columns alone or in combination.J Chromatogr A. 2013 Aug 2;1301:1-9. doi: 10.1016/j.chroma.2013.05.027.
Gentili et al, Comprehensive profiling of carotenoids and fat-soluble vitamins in milk from different animal species by LC-DAD-MS/MS hyphenation. J Agric Food Chem. 2013 Feb 27;61(8):1628-39. doi: 10.1021/jf302811a.
Gentili A, Caretti F., Evaluation of a method based on liquid chromatography-diode array detector-tandem mass spectrometry for a rapid and comprehensive characterization of the fat-soluble vitamin and carotenoid profile of selected plant foods. J Chromatogr A. 2011 Feb 4;1218(5):684-97. doi: 10.1016/j.chroma.2010.12.001
Gentili et al, Screening of Carotenoids in Tomato Fruits by Using Liquid Chromatography with Diode Array-Linear Ion Trap Mass Spectrometry Detection. J Agric Food Chem. 2015 Aug 26;63(33):7428-39. doi: 10.1021/acs.jafc.5b02910.
It depends on which carotenoids you want to determine (isomers, free or esterified carotenoids...). Usually, C30 columns are a better choice for carotenoid analysis by HPLC. Other option, as stated in the previous answer, is the use of two C18 columns in series. In any case, you can have a look at the following reviews (attached) to get a clearer idea according to your needs.
It does depend on which carotenoids you are measuring - beta carotene is the most abundant. There is an evidence based best practice guideline (we produces in Australia) to help.
Cheers
Ronda
Article Laboratory Medicine Best Practice Guideline: Vitamins A, E a...
Agreed with Alessandro Venditti, It depends on your sample matrix and analysis objectives. it its for qualitative & quantitative analysis of a particular carotenoid then yes but if you would like to do analysis of all relative isomers then either use C30 column or try to resolve ions by MS/MS technique for best qualitative and quantitative results.
Takaichi, S., 2000. Characterization of carotenes in a combination of a C18 HPLC column with isocratic elution and absorption spectra with a photodiode-array detector. Photosynthesis Research, 65(1), pp.93-99.
If is the only column that you have available you may try. Cheers!