How are the signal-to-noise ratio and imprecision related? LCGC 27(4) 306-312 (2009) John W. Dolan Erratum: In Figure 1, the signal, S, should be measured from the middle of the noise band to the top of the peak, not from the top of the noise band.
Read More →With trace analysis, a lower limit of detection is always welcomed. LCGC 25(2) 142-152 (2007) John W. Dolan Errata: There is an error in equation 1 of this month’s column. See LCGC 26(5) (2008) for complete explanation. In the November installment of “LC Troubleshooting” [LCGC 24(11) 1184-1190 (2006)], the y […]
Read More →Excess variability is not acceptable in a pharmaceutical method. LCGC 24(12) 1274-1278 (2006) Nastaran Sigari and John W. Dolan Erratum: Note that equation 5 for USP tailing factor is not correct. It should read: TF = w(total)/2*w(front).
Read More →How is the detection limit determined? LCGC 23(12) 1256-1260 (2005) John W. Dolan
Read More →Chromatographers can use a simple set of tests to check system performance. LCGC 20(9) 842-848 (2002) Gerald Hall and John W. Dolan Note that there are several errors in this document. The y-axis scale on Figure 1 should be microvolts, not millivolts. The calculations for Figure 1 are OK, but […]
Read More →Electronic noise can be one of the most frustrating chromatographic problems. LCGC 14(5) 378-382 (1996) John W. Dolan
Read More →Readers’ Questions and Tips LCGC 3(10) 868-874 (1985) John W. Dolan
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