I would like to investigate the mediation of one variable and for that purpose there are 3 scales I use. For those scales, I apply the CFA for checking the validation of the instruments (which been applied to other researches with different criteria of participant).

My question is can I use the same data (after CFA, if some items were dropped) for analysing/ investigating the mediation? If it's allowed, is there any scientific resources that I can get?

Or I have to collect new data of participants with validated item to investigate the mediation?

Looking forward for the guidance.

Thank you so much for your help.