Preparative and Analytical Requirements for Radiochemistry Quality Control
Effective Date: 07/2008
Point of Contact: Quality Engineer for Regulatory Programs
| Quality Control Parameter | Frequency | Acceptance Criteria | Failure Action |
|---|---|---|---|
Preparative Quality Control |
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| Tracer or carrier | Every sample when required by the method. | Appropriate counting statistics or measurement error if mass yield is determined. | Investigate for analyst error. Investigate use against analyte level present in samples and customer DQRs. Re-prepare and analyze affected samples. Discuss in narrative. |
| PB(a) | 1 per batch | <MDC, <5% sample isotope concentration or <5% decision level. | Investigate, evaluate against DQRs, correct, re-prepare and analyze as applicable. |
| LCS or BS(b) |
1 per batch | 80% to 120% or Statistical(c) Vendor or statistical(c) |
Investigate and evaluate against DQRs. Correct. Re-prepare and analyze affected samples. |
| MS(b) | 1 per batch | 75% to 125% or statistical(c) | Investigate. If laboratory error, re-prepare and analyze. If matrix driven, evaluate against DQRs, notify client if still unacceptable. Discuss in narrative. |
| Duplicate(a) | 1 per batch | <20% relative percent difference when the two results are >5 times the MDA or individual uncertainties are <20%. Or, alternately, the duplicates should agree within 2 standard deviations. | Evaluate. If lab error, re-prepare and analyze. If matrix driven, evaluate against DQRs, notify client if still unacceptable. Discuss in narrative. |
Analytical Quality Control |
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| Counter control source | One per day as the system is used or per batch (alpha/beta and liquid scintillation) One per week or after analytical run, whichever is longer (gamma and alpha spectrometry) | Control limits: 3 sigma or ± 3%, whichever is greater. Monitor resolution, efficiency, and energy calibrations to procedure-specified limits. |
Investigate. Recalibrate if necessary. Readjust if keV/channel drift occurs (gamma and alpha spectrometry) |
| Instrument background (blank for liquid scintillation) | One per day as system is used (alpha beta and liquid scintillation) Minimum of every other week or after analytical run, whichever is longer (gamma spectrometry) Minimum of every 4 weeks or after analytical run, whichever is longer (alpha spectrometry) | Use background for results calculation. Monitor background for potential detector contamination. | Investigate as needed. Clean or replace parts as needed. |
(a) Shall be applied at original preparation stage.
(b) The decision to perform a spike during or after preliminary preparation shall be based on sample activity levels. The MS requirement may be met using a tracer or carrier depending on client requirements.
(c) Lab developed procedures shall either meet specifications or show statistical basis for alternative criteria. Alternative criteria are acceptable if they meet client DQRs.
BS = Blank Spike
LCS = Laboratory control sample
MDA = Minimum detectable activity
MS = Matrix spike
PB = Preparation blank.
Note: Nondestructive radioanalytical techniques do not require a BS or matrix spike; however, a LCS is desirable.