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TNI Standards Guidance

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Module: Quality Systems & Chemistry


Subject: Titrants - Documentation and Verification

Question 1

Is it required to independently verify the concentration/strength of all laboratory titrant solutions?

The laboratory must have a written policy on the use of prepared solutions.  The policy shall address record keeping and documentation requirements for each type of solution.

Considerations are as follows:

  • Titrants used directly in the calculation of the analytical result must be independently verified for concentration. 
  • Regardless of use, all prepared solutions affecting analytical quality and calibration must be traceable to the original chemical source to verify purity, concentration, suitability, specifications, etc.  Traceability must be described in a policy or procedure. 


References:

TNI 2009 V1M4-1.7.3.5 c)

1.7.3.5 Reagent Quality, Water Quality and Checks
a) In methods where the purity of reagents is not specified, analytical reagent grade shall be used. Reagents of lesser purity than those specified by the method shall not be used. Documentation of purity shall be available.
b) The quality of water sources shall be monitored and documented and shall meet method specified requirements.
c) The laboratory shall verify the concentration of titrants in accordance with written laboratory procedures.