Generally, the amount of catalyst used is relatively small, such as 1%.
Even if there is relatively strong adsorption, it is negligible for the total reaction volume.
If the influence of this must be taken into account, after the catalyst is separated, it can be extracted with analytical reagents, and the extract and the reaction liquid can be combined to calculate the amount of product.
If one time is not enough, you can repeat it several times to achieve better results