QCS (Quality Control Standard)

Quality Control Standard (QCS) – a secondary solution used to ensure that measurements and method are performing as expected.

• Second Source ­– standards used for quality control that come from a source independent of the ‘primary’. There are a few different definitions for ‘second source’:
  • Lot number – some customers will accept a second source product that either has a different IV lot number from their primary, or was made from an alternate lot of in-house concentrates. All other aspects of the product remain constant.
  • Alternate source material – some customers require that the type of starting material used differs from the material in the primary. For example, if a customer is looking for a chloride primary and secondary, they may accept a primary made from NaCl and a secondary made from HCl. Alternate starting materials help analysts ensure that their process is not affected or biased by the material of the primary, as both standards should return nearly identical chloride results. 
  • Alternate source provider – many customers require that their second source standard comes from a vendor that is independent from the primary. Customers commonly purchase competitor standards to use as second source checks.  
• Continuing Calibration Verification (CCV) Sample – This is a standard that is tested alongside a sample (such as one of our products) that is being certified in order to validate that the procedure is working as intended. This helps monitor for changes or errors in analysis procedures that may invalidate any results obtained in testing. At IV, we call these Procedural Quality Controls (PQCs).
• Spectral Interference Check (SIC) – a method to check your elements of interest for possible interferences from other elements in your method which may disrupt results if they are not corrected for. This is best completed by preparing high concentration single element solutions for each element of interest and monitoring results to see if other elements of interest show up when looking at each element so that ratio of interference to element of interest response can be determined and used for correction.
• Interference Check Solution (ICS) – standard that contains known concentrations of interference elements (elements the instrument may mistake for one of your elements of interest), used to measure effectiveness of interference correction techniques (which are generally established based on the SIC procedure).