Focused, concentrated, specialized…they have different implications. If you say you were dedicated, it means in the sense of being solemnly devoted, almost in a religious sense.

On the other hand, it is logical to use focus or concentrate…

During my time as head of the institution, I focused on research and technical issues for the oil and gas industry, but this all changed when in 1999 …

or

During my time as head of the institution, I concentrated on research and technical issues for the oil and gas industry, but this all changed when in 1999 …

The inference in the two options I gave you is that you made a logical choice where you were going to place your time and attention.

However: ‘I was dedicated’ is gramatically correct in this context.

I would change ‘the research’ by omitting ‘the’.