USP Chapter 621 for Chromatography: Calculation of signal-to-noise ratio - Tip316

OBJECTIVE or GOAL

Update concerning the changes to USP Chapter 621 regarding the calculation of signal-to-noise (S/N) ratio. This applies to the EP chapter 2.2.46 as well.

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PROCEDURE

USP Chapter 621 

1. As of 1 December 2022, the revised USP chapter 621 was published. One of the changes is the half-height multiplier for the signal-to-noise ratio changed from 5 to 20 (figure 1).
   
2. After much consideration, the USP has decided that as of 1 April 2023, they will revert to a half-height multiplier of 5 (figure 2). 
   

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EP Chapter 2.2.46

1. As of 1 January 2023, the revised EP Chapter 2.2.46 was published with a half-height multiplier change from 5 to 20 (Refer to figure 1). 
2. The EP has decided to revert to a half-height multiplier of 5 as of 1 January 2024 (Refer to figure 2). 

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Note: What to do until the changes become official? 
By convention it is acceptable to follow the 'future' guidance, however, Waters cannot represent or speak for FDA in this regard. This is a discussion you should have internally with your compliance officer.
 

ADDITIONAL INFORMATION

This can be done with either the Pro or QuickStart interface.

Please see waters response to this change concerning thier SQT product: Should Waters qualification products calculate s/n in the manner detailed in USP621? - WKB241191