CSlogo1.gif (9302 bytes)

HPLC HINTS & TIPS for Chromatographers

Tip# 113: How Do C18 Phases Differ ?

Reversed phase HPLC columns which utilize the octadecyl functional group often differ in many ways. Besides the particle size, shape of the stationary phase (irregular or spherical) and the coating chemistry used, two other  very important ways that columns can differ from one another are in their available surface area and the extent to which those surfaces are covered with the phase coating (i.e. covalently bonded, non-covalently coated and the total carbon %). When comparing columns for use in validated methods, be sure and consider these factors to minimize the number of changes to your method. Always test several columns of the same type to determine the reproducibility of batch to batch variation too. Some manufacturers have mastered the art of preparing and packing columns which achieve high batch to batch reproducibility. After all, what good is a column in your method if the results are not reproducible when you purchase another one some time later?

> Bill Letter, 07/18//2011.

HINT's & TIPS Back to the Table of Contents

   WB01343_.gif (1341 bytes)

Chiralizer™ Services, L.L.C., Newtown, PA   USA

Copyright 2011, Chiralizer™ Services, L.L.C. All Rights Reserved. Chiralizer, Column Swapper & LC Spiderling are trademarks of Chiralizer Services, Newtown, PA   USA. *These "Hints & Tips" are protected by copyright and are not to be copied or duplicated in whole or part without the written permission of Chiralizer Services, LLC.