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<br />ACZ Laboratories, Inc. August 10, 2007 <br />Quality Assurance Plan Version 12 <br />SOPAD018.08.07.12 Page 34 of 96 <br />9.2 Instrument Calibration <br />The accuracy of all instrument-generated data is ultimately dependent upon the proper initial calibration of the <br />instrumentation used for any particular analysis. In order to perform quantitative measurements, the initial <br />calibration must be established and verified, at the frequency required by the method or by the manufacturer <br />(whichever is more stringent), before samples are analyzed. In general, calibration or standardization involves <br />defining the relationship between instrument response and the amount or concentration of analyte introduced <br />into the instrument. The graphical depiction of this relationship is referred to as the calibration curve. <br />Calibration frequency must be performed in accordance with the manufacturer's guidelines, test method or <br />other regulatory requirements, or client contract stipulations, whichever is most stringent. Every calibration <br />or standardization must meet the acceptance criteria stated in the SOP and must be subsequently verified by <br />analyzing an initial calibration verification standard (ICV) or other control standard (if specified in the SOP) <br />that contains all target analytes and has been prepared or obtained from a different source than the one used to <br />prepare the calibration standards.' Whenever possible, calibration standards and the second-source <br />verification standard should be prepared on different days. If they are prepared concurrently, then another <br />qualified analyst should prepare the second-source verification standard. This eliminates the possibility of the <br />same analyst preparing both solutions incorrectly, an error difficult to detect. <br />A continuing calibration verification standard (CCV) containing all analytes of interest must be analyzed at the <br />frequency stated in the test SOP to ensure the stability of the initial calibration curve has not varied over time <br />due to any change in the analytical instrument and its detection system, such as instability of standards, <br />instrument cleanliness, column performance, matrix effects, flow changes, and changes within the laboratory <br />environment. <br />For applicable methods, all initial and continuing calibration steps must be clearly detailed in the test SOP. <br />Additionally, each test SOP must specify the frequency and acceptance limits for the calibration and subsequent <br />verification (ICV and CCV). In general, acceptance criteria are method-specific; however, the SOP may also <br />include requirements of other regulatory agencies. Prior to resuming sample analysis, immediate corrective <br />action must be taken if the calibration, ICV, or CCV is outside of the acceptance criteria. Technical corrective <br />actions are described in the individual test SOPs. Refer also to section 11.2 for additional information. <br />General calibration guidelines are listed below and detailed information is provided in ACZ's SOP Maintenance <br />and Control of Calibration and Test Equipment (SOPAD013). <br />• Understand the method requirements for calibration (minimum number of standards, etc.) <br />• Use the correct calibration model (linear, second-order, etc.) <br />• Include all target analytes in the calibration standards and second-source standard <br />• Analyze a calibration standard with a concentration less than or equal to the reporting limit.'` <br />• Do not remove points from the middle of the calibration (only high or low standard may be dropped). <br />• Calibration is a single-event process. A retest of a calibration standard must be performed immediately. <br />• Documentation and resolution of calibration abnormalities is absolutely critical <br />1 If a second source standard is not available then a different lot(s) of the same standard(s) may be used. If a different <br />lot is not available then an analyst who did not prepare the calibration standards may prepare the calibration <br />verification standard. The latter is an exception, and an attempt must first be made to purchase a different lot from the <br />same vendor whenever a second-source standard is not commercially available. <br />'` In general, the concentration of the low calibration standard is equal to the reporting limit, because lesser values are <br />qualified as estimated; however, actual lab practice may differ and must be stated in the test SOP. <br />2773 Downhill Drive 970-879-6590 <br />Steamboat Springs, CO 80487 www.acz.com <br /> <br /> <br /> <br /> <br />1 <br /> <br /> <br /> <br /> <br /> <br />1 <br /> <br /> <br />1 <br /> <br /> <br /> <br />