ICV demonstrates that the instrument is capable of acceptable performance at the beginning of the analytical run. 1) Immediately after each system has been calibrated, the accuracy of the initial calibration must be verified and documented for each target analyte by the analysis of an ICV solution(s). If the ICV %R falls outside of the control limits, the analysis should be terminated, the problem corrected, the instrument recalibrated, and all affected samples reanalysed. 2) If the ICV solution is not available from USEPA, or where a certified solution of an analyte is not available from any source, analyses shall be conducted on an independent standard at a concentration level other than that used for instrument calibration (or the CRI), but within the calibrated range. 3) The ICV solution shall be run at each analytical wavelength used for analysis.

CCV demonstrates that the initial calibration is still valid by checking the performance of the instrument on a continuing basis. 1) To ensure accuracy during the course of each analytical run, the CCV shall be analysed and reported for each wavelength used for the analysis of each analyte. 2) The CCV standard shall be analysed at a frequency of 10% or every two hours during an analytical run, whichever is more frequent. The CCV standard shall also be analysed at the beginning of the run, and again after the last analytical sample. 3) The analyte concentration(s) in the CCV standard(s) shall be different than the concentration used for the ICV, and shall be one of the following solutions at, or near, the mid-range levels of the calibration curve: A. USEPA solutions. B. National Institute of Standards and Technology (NIST) standards; or C. A Laboratory-prepared standard solution (self-prepared or commercially available). 4) The same CCV standard solution shall be used throughout the analysis runs for a Sample Delivery Group (SDG). 5) The CCV shall be analysed in the same fashion as an actual sample. Operations such as the number of replicate analyses, the number and duration of the instrument rinses etc., affect the measured CCV result and are not to be applied to the CCV to an extent greater than was applied to the associated analytical samples. If the %R of the CCV was outside of the control limits, the analysis should be terminated, the problem corrected, the instrument recalibrated, and the preceding 10 analytical samples or all analytical samples analysed since the last compliant calibration verification reanalysed.