Investigate the copper spike recovery failure

What is going on

Nonconformance NCR-26-071 records a copper matrix spike recovery of 68 percent in metals batch M-2609-03 against a limit of 80 to 120 percent. Fourteen client samples are on hold and none have been reported. Priya Venkatesan wants a proper root cause investigation rather than a rerun, because a similar copper result was seen in July and dismissed as a one-off. The batch data, the spike solution preparation record, the certified reference material certificates, the instrument maintenance log and the analyst's worksheet are all available. The quality meeting is on Thursday and the client is asking for results.

Your brief

Investigate the failure using the nonconformance procedure, establish the root cause with evidence, decide the fate of the fourteen samples, define corrective actions with owners and dates, update the register and prepare a one page summary for the section manager.

Work through it

You do not need to do it all. Doing a few of these will show you what the work is like. Your ticks and notes stay on this device.

• Read the nonconformance procedure and the register entry for NCR-26-071, and list every record you need to examine.
• Review the batch data for calibration, blank, duplicate and control sample results and confirm whether the failure is isolated to the spike or affects other quality control.
• Examine the spike solution preparation record, stock standard certificate, expiry and dilution calculation, and the balance and pipette check records used on that day.
• Check the instrument maintenance log and the July batch data for any earlier copper anomaly, and interview the analyst about the batch.
• Apply a structured root cause method such as the five whys and document the most probable cause with the supporting evidence and any alternatives ruled out.
• Decide whether the fourteen samples can be reported, must be re-digested or must be reanalysed, and record the decision and its justification.
• Record the root cause, corrective actions with owners and due dates, and the verification method in the nonconformance register, and update the sample register for the affected samples.
• Write a one page summary for Priya Venkatesan for the quality meeting.

What someone in this role would produce

• Root cause analysis with evidence
• Decision record for the fourteen samples
• Updated nonconformance register entry
• Sample register updates
• One page summary for the section manager