General Chapter/Section(s): <467> Residual Solvents/Pressurization Time
Expert Committee(s): General Chapters
No. of Commenters: 1
Comment Summary #1: The commenter requested two changes to the Pressurization
time section: 1) increase the syringe temperature range 5 to 10ºC higher than the
equilibration temperature and 2) add the phrase “if appropriate” because equilibration
temperatures are typically used for injectors with a transfer line. Pressurization time is
not applicable to syringe-based injectors.
Response: Comment incorporated.
General Chapter/Section(s): <1010> Analytical Data-Interpretation and Treatment/
Multiple Sections
Expert Committee(s): Statistics
No. of Commenters: 3
Comment Summary #1: The commenter indicated that in the Sampling Considerations
section, systematic random sampling is recommended as a sampling scheme that may
be preferred to simple random sampling in certain situations. While the stated reasons
are valid, there are analytical issues with variance estimation associated with data
collected via systematic sampling. Although the last sentence of the sub-section states
that the tests discussed in the remainder of the chapter assume that simple random
sampling was performed, the commenter recommend including an additional statement
recommending consultation with a statistician to identify the optimal sampling strategy.
Response: Comment incorporated.
Comment Summary #2: The commenter indicated that in Appendix C, the
recommended approach assesses the data first for a single outlier (correctly), then tests
the reduced dataset again, using the same approach, to ensure there are no other
outliers on the same side of the mean. The commenter viewed this as incorrect
because there are outlier tests designed for more than one outlier on the same side of
the mean. However, the commenter noted the warning in the conclusion and suggested
making the warning more prominent at the end or beginning of Appendix C.
Response: Comment incorporated. The following text was added under the Dixon-Type
Tests subsection: "Dixon provides for testing for two outliers simultaneously; however,
these procedures are beyond the scope of this Appendix. The stepwise procedure
discussed below is not an exact procedure for testing for the second outlier as the result
of the second test is conditional upon the first. Because the sample size is also reduced
in the second stage, the end result is a procedure that usually lacks the sensitivity of
Dixon's exact procedures.” The conclusion paragraph was replaced with the following
text: “Therefore, 95.7 is declared to be an outlier but 99.5 is not an outlier.”
Comment Summary #3: The commenter indicated that Appendix E, Sample Size
section, the formula for 2
L σ should be revised throughout the entire chapter from “RSD”
to “%RSD.”
Response: Comment incorporated.
Expert Committee-initiated Change #1: Under Appendix B, the Expert Committee
members proposed to revise the sentence from “Nevertheless, many statistical software
packages can easily handle unequal replication" to “Many statistical software packages
can easily handle unequal replication.”