Introduction to Modern Liquid Chromatography, Third Edition part 89. 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. . | 836 TROUBLESHOOTING Temperature Problems Changes in column temperature affect values of tR and k. A 1 C increase in column temperature will normally decrease retention by 1-2 Section so a method that is operated without column-temperature control will be subject to changes in retention as the temperature of the laboratory changes during the day. Temperature changes alsocan influence selectivity Section so shifts in relative retention may also be laboratories havestable dafimetemperatures butfor energy cononrrotioado not pronide fliotomo quobsyyf temperaturocontrol atnight. Also eventhougnoqe leboratniy tempotasornio esiatively qnnstant afmeasured at a wall-moyneed thetmostar thelnaallempeqosnqe ctmflucluaOdssgIufioenda especially ttohodting duct c in i ott irat t i-ios err t HbLC tfm. Fas tlbs oeosao problems neietedlo temperatuee teot tobe Hil ife ao dyctic ehangeo innerontsan throughoutoqsday. Temperaiiire-eeratea rotenoionorobiems aaoOr qe i etoti iis e using a co umn ooai Fnasatedmaeqngewherelthasstabio trmperaHbeeonteol Section . Ioodenuaee onhsmnsemorraSFce eaoerolaroq san caute easi soaps problems dpheiceibad it . aerent on-PieblemSemrlqeso This section hroayssesretentieo-iime peoblemsinrotmeof templome lea tbetelaoer items in Trblm . Abrupt changes in retention are usually easy to isolate. If these occur when the column is changed the column itself is the most likely cause. Re-installation of the previoua columnshould variation is much less commoF wioh Onyay saidh-qurityllype-0 silieacolumnS bof wafcomrnonplooe with the lower-b oitb type-A columns that may still be in use for some legacy methods. Tegacymethodsmay reqaiaeadjyetmenfoO themobilepnaoe wsFieadt new columto inorOer to meetorstrt tHeaObitai en ds nn i is ioteetOefseveral columns feamohr oamebanca ot daeaing mqohon for a morerobust eeyarasionirenothet ralusio7ibut it moynet .
