Final answer:
The expiration of stability on an open vial of Quality Control solution is determined by conditions such as room temperature stability, post-preparative stability, and response to freeze-thaw cycles, and it must meet the requirement of maintaining the mean concentration within ± 15% of the nominal value.
Step-by-step explanation:
Understanding the expiration of stability on an open vial of Quality Control solution involves evaluating various factors including short-term stability at room temperature, post-preparative stability, and the stability of the solution through freeze-thaw cycles. Typically, the stability of an open vial of Quality Control solution is dependent on the recommended conditions provided by the manufacturer which details long-term storage conditions and handling procedures. For instance, the mean concentration of the solution must remain within ± 15% of the nominal concentration for the solution to be considered stable.
In early study phases like the detection and chromatographic condition stage, stability assays of stock solutions are necessary. These include evaluating former sample extraction procedures, ensuring selectivity to avoid interferences, and establishing a calibration curve with a low number of standards (n = 3-5) to confirm reasonable precision and accuracy. The solution's stability is also subject to conditions such as the duration for which it remains at a sample processing temperature or at room temperature after preparation and how it withstands successive freeze-thaw cycles.