Hi. A unit of enzyme activity is expressed in 'mol amount/time (in min or second)'. To compare your data with others, it will be necessary to obtain specific activity, i.e., 'mol amount/time/protein amount (usually in milligrams)'. Probably in literatures the activity is expressed in this way (e.g. nmol/min/mg protein). You need to convert your value (mM, concentration) into the proper unit by considering the time of reaction and the amount of protein of your sample.

Can I know , how determination of NADH oxidase in the seum by simple method?

Thank you