The same sensor may be used with a wide range of tubing.
Thus, it is preferred to design the study to only reflect the extractables of the sensor.
For flow-through sensors, it will be necessary to use tubing to achieve enough volume for analysis as only the inner surface of the sensor is wetted. This requires a separate study setup of tubing to subtract the extractables associated with the tubing.
Express the results as µg/cm2. When there are no other sensors in the component family the results can be expressed as µg/sensor.