hi.
you could go for confirmatory testing for each nitrosamine to see whether each NA is actually found in your final product.
in case >10% then this NA imp should be included in final specs. In case more than one nitrosamines are identified in final product, then you should follow the principles as described under EMA Q&A 10 for Calculation of limit when more than one nitrosamine is identified in the same product
I trust you can also go through
Calculation of limit when more than one nitrosamine is identified - Limits of Nitrosamines - Nitrosamines Exchange
FDA Acceptable intake limit for multiple nitrosamines in one drug product -Calculation - Limits of Nitrosamines - Nitrosamines Exchange
Total impurities limit if more than one nitrosamine impurities are observed in product - Limits of Nitrosamines - Nitrosamines Exchange
Nitrosamine Calculation in Sita + Met Tablets - Limits of Nitrosamines - Nitrosamines Exchange