2017-6. Method Adjustment the USP Way

When you want to adjust a United States Pharmacopoeia (USP) method for a different size column or to meet system-suitability criteria that fail, how much of a change can you make without revalidating the method? LCGC 35(6) 368-373 (2017) John W. Dolan  

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2013-5. Gradient Elution, Part III: Surprises

Sometimes when changes are made to gradient conditions, the result isn’t what was expected. LCGC 31(5) 382-389 (2013) John W. Dolan ERRATUM: The last word on p. 388 should be “decrease” not “increase.” A change in particle size from 3 microns to 5 should reduce the pressure, not increase it.

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2009-8. Too Many Changes

Remember the Rule of One — change just one thing at a time LCGC 27(8) 606-610 (2009) John W. Dolan Erratum: LCGC 27(6), p 478. Table 1, in the third column, the next to last line should read 403913, not 36827, and the 36827 should shift down one row.

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2008-5. How Do I …?

Are you stuck on which step to take next? LCGC 26(5) 440-446 (2008) John W. Dolan Erratum: equation 1, February 2007, LCGC 25(2), 142-152 contains an error summarized at the end of this article.

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