Abstract Qualification of analytical instruments has been a complex undertak- ing, not because the process of qualifying instruments is complex, but because several opinions abound on how to perform a successful qualification. Recently, the United States Pharmacopeia issued General Chapter <1058> to provide guidance for Analytical Instrument Qualification (AIQ). The draft chapter has been published in Pharmacopeial Forum (latest in PF 32:6) and has gone through multiple cycles of public comments. The chapter is scheduled to become official in 2008 (USP 31). The purpose of this chapter is to provide general guidance for the qualification of analytical instrument establishing a common terminology and defining roles and responsibilities of those associated with an instrument’s qualification. 1. Introduction Analytical instrumentation plays a critical role in the analytical information generation process. The USP has established several chapters to guide the process from the sample receipt to reportable data. These chapters include the use of weights and balances Chapter <41>, the use of volumetric apparatus Chapter <31>, validation of compendial procedures Chapter <1225>, verification of compendial procedures Chapter <1226>, and analytical data interpretation and treatment Chapter <1010> among others. These help the user assure the quality and the compliance of the analytical data generated. The USP has developed the Analytical Instrument Qualification (AIQ) Chapter <1058>. This report summarizes the chapter and its recommended process for setting instrument qualification tolerances. 2. Analytical Instrument Qualification Process Prior to the use of an analytical instrument for the generation of reportable data, it is imperative to provide documented evidence that the instrument is capable of performing its intended function. A qualified analytical instrument provides Chapter 13 Setting Tolerances for Instrument Qualification USP Chapter <1058> Horacio N. Pappa and Kim Huynh-Ba From: Pharmaceutical Stability Testing to Support Global Markets: Pharmasp, Edited by: K. Huynh-Ba, DOI 10.1007/978-1-4419-0889-6_13, © 2010 American Association of Pharmaceutical Scientists 93