Introduction to Modern Liquid Chromatography, Third Edition part 30. High-performance liquid chromatography (HPLC) is today the leading technique for chemical analysis and related applications, with an ability to separate, analyze, and/or purify virtually any sample. Snyder and Kirkland's Introduction to Modern Liquid Chromatography has long represented the premier reference to HPLC. This Third Edition, with John Dolan as added coauthor, addresses important improvements in columns and equipment, as well as major advances in our understanding of HPLC separation, our ability to solve problems that were troublesome in the past, and the application of HPLC for new kinds of samples. . | 246 THE COLUMN Table Approximate Plate Number for Well-Packed Columns under Optimized Test Conditions Particle Type Particle Diameter pm Column Length mm a Plate Number N Totally porous 5 30 2 500-3 000 Totally porous 5 50 4 500-5 000 Totally porous 100 8 000-10 000 Totally porous 5 150 12 000-1 5 000 Totally porous 5 250 20 000-25 000 Totally porous 35 30 3 000-4 000 Totally porous 35 50 5 500-7 000 Totally porous 35 100 10 500-14 000 Totally porous 35 150 17 000-21 000 Fused-core 30 7 000-8 000 Fused-core 50 9 000-11 000 Fused-core 100 18 000-22 000 Fused-core 150 28 000-34 000 Totally porous 30 6 000-7 000 Totally poroue 50 10 000-12 000 Totally porous 100 20 000-25 000 Note Small neutral test-solute low viscosity mobile phase ambient temperature measured at the plate-height minimum s Estimated valnssfor . columns. bAn average forsommersitlluavailable sub-2-pm particles. new columnthatmetthe manufacturer problemsareencountered with a routine method that might be caused by the column values of N and either As and TF rault compauedwith priotvalues for a good column. In this way a bad columocaebn cnufrinedasthecoeteof ths proldcni. Every column used for a routine method has a finite lifetime number of injected samples be-orecolmmifanma that dfpundsonsepaeationconditions espfc-a--y mobile-phaso pH undtemofsaturc. R r inmb kof 1000 te 20 1- analyses should b apo ssiblefoimcetsftiaa-0asfdcchlmn1-pastiaularlcrevessudphase aolumns. othersamples with minimoescmple preparation suah as extraats of blood plansor eeiueat tictuetO0 etd Oh thOiaaysoasii-a oi eld iacl aolumn lifetime. COLUMN HANDMNG The perfoemudae andlife of the aolumn depend on how it is used and handled. During heavy use with dirty samples espeaially samples from biologiaal sources aolumns aan develop severe peak tailing Fig. or double peaks for eaah component Fig. usually the result of a partly bloaked frit a .
