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<br /> <br /> <br /> <br /> <br /> <br /> <br /> <br />0 <br /> <br />ACZ Laboratories, Inc. August 10, 2007 <br />Quality Assurance Plan Version 12 <br />SOPAD018.08.07.12 Page 45 of 96 <br />11.1.3.1 Surrogates <br />Surrogates are organic compounds that are similar to the target analyte(s) in chemical <br />composition and behavior in the analytical process, but are not normally found in <br />environmental samples. Surrogates are included in the scope of Organic methods and are <br />used to evaluate accuracy, method performance and extraction efficiency and shall be added <br />to environmental samples, controls, and blanks, in accordance with the method requirements. <br />Whenever a surrogate recovery is outside the acceptance limits, the corrective action(s) stated <br />in the test SOP must be performed. If corrective actions could not be performed or are <br />ineffective, then the appropriate qualifier is applied to the sample results and reported to the <br />client. <br />11.1.3.2 Matrix Spike Samples <br />A matrix spike sample (however named) is used to determine the level of bias (accuracy) <br />associated with a particular matrix. For the purposes of this document, "MS" designates a <br />matrix spike, and "MSD" designates a matrix spike duplicate. Spikes are prepared by adding a <br />known and appropriate quantity of each target analyte to a replicate aliquot of client sample. <br />The required analytical frequency is specified by the method or other regulating entity and is <br />indicated in the test SOP. Each result is evaluated against the acceptance criteria, and matrix <br />effects are determined and reported to the client. The following evaluation criteria apply to <br />spikes that are subjected to processing steps and post-digestion spikes (analytical spikes). <br />• Percent Recovery (%R) is considered for all spikes. <br />• %R is evaluated only if the theoretical concentration in the spiked aliquot is greater <br />than or equal to the reporting limit; otherwise, each associated client sample must be <br />reported with the appropriate qualifier, regardless of %R. <br />• If %R for the MS and/or the MSD is outside of the acceptance limits, the RPD <br />passes, and all other pertinent prep and instrument QC passes, then each associated <br />client sample may be accepted and reported with the appropriate qualification. <br />11.1.3.3 Matrix Duplicates and Matrix Spike Duplicates <br /> <br />The matrix-specific precision associated with an analysis is determined through the use of a <br />matrix duplicate (DUP) or spike duplicate (MSD), which are performed at a frequency <br />specified by the method or other regulating entity (refer to the specific test SOP). The results <br />are evaluated, and the matrix effect on precision are determined and reported to the client. <br />Relative Percent Difference (RPD) is considered for all duplicates except non- <br />drinking water samples for radiochemical analyses (see 12.4.4). <br />RPD for a spike duplicate is evaluated only if the observed concentration is greater <br />than or equal to the reporting limit; otherwise each associated client sample must be <br />reported with the appropriate qualifier. <br />2773 Downhill Drive 970-879-6590 <br />Steamboat Springs, CO 80487 www.acz.coin