In-Process Revision of USP General Chapter 31

Apr 15, 2011

Bjoern_CarleThe United States Pharmacopeia is currently revising General Chapter 31 “Volumetric Apparatus.” The proposed changes to this chapter include a closer alignment of the specifications for volumetric apparatus to those described in the appropriate ASTM standards. For example, drain rates for pipettes and burettes have been removed from Chapter 31 as these did not reflect the ASTM regulations. Further, data tables for accuracy requirements, which are now referenced in Chapter 31, are excerpts from the corresponding ASTM standards and are limited to the most common apparatus sizes. Readers are directed to the corresponding ASTM standards for complete listings of all volumes. This means the full range of pipettes, including micropipettes, are now included in this chapter.

Another noteworthy change is the inclusion of “automatic apparatus” in this chapter. This means the revised Chapter 31 would allow the use of piston-operated pipettes and robotic pipetting equipment (e.g., automated liquid handlers) to manipulate volumes, as long as their tolerances meet or exceed those specified in USP General Chapter 31 for Class A volumetric apparatus.

While the accuracy specifications described in Chapter 31 refer to Class A glass volumetric apparatus, this revision continues to include plastic volumetric apparatus, for which it stipulates Class B capacity tolerances.

The proposed revision to USP General Chapter 31 can be reviewed online, for free, in the Pharmacopeial Forum.  Learn more

Public review of these revisions is encouraged, and comments can be submitted to the USP until 31 May 2011, as explained on the website.


About the Author

Bjoern Carle, Ph.D.

A. Bjoern Carle, PhD, is the PCS Product Manager at Artel, where he supports product development, scientific marketing, and technical training efforts. Dr. Carle earned his Vordiplom (B.S.) in Chemistry at the University of Stuttgart (Stuttgart, Germany), his M.S. and PhD in Organic Chemistry at the University of Cincinnati (Cincinnati, OH), and performed post-doctoral research at Harvard Medical School / Massachusetts General Hospital (Boston, MA). He can be contacted at 207-854-0860.