In his final column before retirement, John Dolan reminisces about his years as the author of “LC Troubleshooting,” and some of the hcanges that have taken place in liquid chromatography (LC) technology during that time. LCGC 35(10) 746-750 (2017) John W. Dolan *ed. notes: (1) This is John Dolan’s last […]
Read More →The silica-based packing in reversed-phase columns is not inert. Here we consider what happens when the mobile-phase pH is too high or too low. LCGC 34(2) 106-113 (2016) John W. Dolan
Read More →Particulate matter from the sample or the system can cause havoc in the chromatogram. LCGC 33(12) 894-899 (2015) John W. Dolan Errata: Note that there was a transposition error in this and two associated articles. In the referenced table, the words “Symptom” and “Cause” have been reversed. That is, “Cause” […]
Read More →The potential causes are considered for peak distortion for the first two peaks in the chromatogram. LCGC 33(7) 464-469 (2015) John W. Dolan
Read More →Both the volume of the sample injection and the solvent in which the sample is dissolved can affect the appearance of the chromatogram. LCGC 32(10) 780-785 (2014) John W. Dolan
Read More →Why do some peaks front and others don’t in the same method? LCGC 31(12) 992-997 (2013) John W. Dolan
Read More →The solvent chosen for injection can affect the appearance of chromatograpic peaks. LCGC 30(10) 898-902 (2012) Bandar Alshli and John W. Dolan Erratum: (from 30(12): equation 2 should read: w = 4 tR / N^0.5.With this change, all the calculated values of peak widths and recommended injection volumes should be […]
Read More →Retention-time drift, temperature control, and broad peaks from a new column are the topics in this month’s discussion. LCGC 30(8) 634-636 (2012) John W. Dolan
Read More →What do you do when the peak shape changes? LCGC 30(7) 564-569 (2012) John W. Dolan Erratum: see 30(5)
Read More →What do you do when an unexpected peak appears in the chromatogram? LCGC 30(5) 392-400 (2012) John W. Dolan Erratum: (from 30(7), on p 394, the calculation showed that 0.1% x 0.1% = 0.01%, when in fact is should have been 0.1% x 0.1% = 0.0001%
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