Inorganic Analytical Quality Control Requirements
Effective Date: 07/2008
Point of Contact: Quality Engineer for Regulatory Programs
| Quality Control Requirements | Frequency | Acceptance Criteria | Failure Action |
|---|---|---|---|
Inductively Coupled Plasma Spectrometer (ICP) and Flame Atomic Absorption (FLAA) |
|||
| ICV | Immediately after calibration (typically mid-range) | 90% to 110% | Investigate failure for analytes of interest. Recalibrate for analytes of interest. |
| ICB | After ICV | <EQL | Investigate failure for analytes of interest. Recalibrate for analytes of interest. |
| CCV | After every 10 samples and at the end of analytical run | 90% to 110% | Investigate failure for analytes of interest. Recalibrate for analytes of interest. Reanalyze samples, as appropriate. |
| CCB | After every CCV | <EQL | Investigate failure for analytes of interest. Recalibrate for analytes of interest. Reanalyze samples, as appropriate. |
| LLS | At the beginning of the analysis (but not before the ICV or ICB) | Recommended: 75% to 125% |
Investigate. Discuss in narrative. |
| Interference check standard (ICP only) | After the ICV, after the ICB and at the end of the run | 80% to 120% | Investigate. Reanalyze all samples. |
| Serial dilution | 1 per batch as required or needed | <10%, when analyte >10 times IDL after 5-fold dilution | Investigate. Re-prepare/Re-analyze as necessary. Discuss in narrative. |
| Post spike | MS fails or new and/or unusual matrix is being analyzed | Recommended: 75% to 125% | Investigate. Re-prepare/Re-analyze as necessary. Discuss in narrative. |
Inductively Coupled Plasma Spectrometry/Mass Spectrometry (ICP/MS) |
|||
| ICV | Immediately after calibration (typically mid-point region) | 90% to 110% | Investigate failure for analytes of interest. Correct. Recalibrate for analytes of interest. |
| CCV | Every 10 samples and at the end of the run | 90% to 110% | Investigate failure for analytes of interest. Correct. Recalibrate for analytes of interest. |
| ICB | After ICV | < EQL | Investigate failure for analytes of interest. Correct. Recalibrate for analytes of interest. |
| CCB | After each CCV | < EQL | Investigate failure for analytes of interest. Correct. Recalibrate for analytes of interest. |
| Interference check standard | After ICV and ICB and every 12 hours | Monitor for interferences which will impact samples | Investigate. Correct/Reanalyze/Flag. |
| Quality Control Requirements | Frequency | Acceptance Criteria | Failure Action |
| Serial dilution | 1 per batch of samples prepared or when internal standard criteria failure occurs | ± 10% difference when analyte > 100 times IDL | Investigate for analyst error. Discuss performance in narrative. |
| Post spike | When MS fails or when new or unusual matrix is encountered | 75% to 125% | Investigate for analyst error. Discuss performance in narrative. |
| Internal standard | Every sample, QC sample, blank, and standard | 30% to 120% | Perform serial dilution. Evaluate. Correct/Report. |
Mercury, Cold Vapor Atomic Absorption (CVAA) |
|||
| ICV(a) | Immediately after calibration (typically mid-range) | 80% to 120% | Investigate. Correct. Recalibrate. |
| ICB | After ICV | < EQL | Investigate. Correct. Recalibrate. |
| CCV | After every 10 samples and at the end of analytical run | 80% to 120% | Investigate. Recalibrate. Reprepare and reanalyze samples, as appropriate. |
| CCB | After each CCV | < EQL | Investigate. Recalibrate. Reprepare and reanalyze samples, as appropriate. |
| LLS | After ICV and ICB | Recommended: 75% to 125% | Investigate for analyst error. Discuss in narrative. |
Cyanide (Spectrophotometric) |
|||
| ICV(a) | Immediately after calibration (typically mid-range) | 85% to 115% | Investigate. Recalibrate. |
| ICB | After ICV | < EQL | Investigate. Recalibrate. |
| CCV | After every 10 samples and at end of analytical run | 85% to 115% | Investigate. Recalibrate. Reanalyze samples, as appropriate. |
| CCB | After every CCV | < EQL | Investigate. Recalibrate. Reanalyze samples, as appropriate. |
| LLS | After ICB | Recommended: 75% to 125% | Investigate. Discuss in narrative. |
| Quality Control Requirements | Frequency | Acceptance Criteria | Failure Action |
Graphite Furnace Atomic Absorption (GFAA) |
|||
| ICV | Immediately after calibration (typically mid-range) | 90% to 110% | Investigate. Recalibrate. |
| ICB | After ICV | < EQL | Investigate. Recalibrate. |
| CCV | After every 10 samples and at the end of analytical run (may be undistilled) | 80% to 120% | Investigate. Recalibrate. Reanalyze samples, as appropriate. |
| CCB | After every CCV | < EQL | Investigate. Recalibrate. Reanalyze samples, as appropriate. |
| LLS | After ICB | Recommended: 75% to 125% | Investigate. Discuss in narrative. |
| Post Spike | When MS fails | 75% to 125% | Investigate for source of error. Re-prepare/reanalyze as necessary. Discuss in narrative. |
Ion Chromatography (IC) |
|||
| ICV | After initial calibration (typically mid-range) | 90% to 110% | Investigate. Recalibrate. |
| ICB | After ICV | < EQL | Investigate. Recalibrate. |
| CCV | At the beginning of the analytical sequence when initial calibration is not run, after every 10 samples, and at the end of analytical run | 90% to 110% | Investigate. Recalibrate. Reanalyze samples, as appropriate. |
| CCB | After every CCV | < EQL | Investigate. Recalibrate. Reanalyze samples, as appropriate. |
| LLS | After ICB | Recommended: 75% to 125% | Investigate for analyst error. Discuss in narrative. |
pH |
|||
| ICV | Immediately after calibration | ±0.1 pH unit | Investigate. Recalibrate. |
| CCV | After every 10 samples and at the end of analytical run | ±0.1 pH unit | Investigate. Recalibrate. Rerun all samples since last valid CCV. |
Ion Specific Electrode and Colorimetric/Spectrophotometric Methods |
|||
| ICV | Immediately after calibration for working curve technique, prior to analysis of samples for all other techniques | 90% to 110% | Investigate. Recalibrate. |
| ICB | After ICV | < EQL | Investigate. Recalibrate. |
| CCV | After every 10 samples and at end of the run (not applicable to titration methods) | Based on long term statistical performance | Rerun all samples since last valid CCV. |
| CCB | After each CCV | < EQL | Rerun all samples since last valid CCB. |
Titrimetric Methods (e.g., Ammonia, Hexavalent Chromium) |
|||
| ICB | 1 per batch | < EQL | Investigate. Correct. Reanalyze. |
| Titrant Verification | 1 per batch | 80% to 120% | Investigate failures. Correct. Re-standardize titrant and reanalyze samples. |
(a)If the ICV is representative of the sample matrix and prepared with the samples, then the ICV may be used as both the BS and ICV.
AS = Analytical spike
CCB = Continuing calibration blank
CCV = Continuing calibration verification
ICB = Initial calibration blank
ICV = Initial calibration verification
LLS = Low-level standard
MS = Matrix spike.