ph值在液相色谱中的影响-英文.pdf

Ana@~a Ch~imcu Am, 250 (1991) 1-19 Elsewer Snence Pubhshers B V , Amsterdam Effects of pH in reversed-phase liquid chromatography Peter J Schoenmakers *, Sylvle van Molle ‘, Carmel M G Hayes * and Louis G M Uunk Phdrps Research Laboratorres, P 0 Box SlXW0, 5000 JA Emihoven (Netherlands) (Received 23rd May 1991) AbStl%Ct The effects of conconutant vanahons m pH and orgamc mfler concentration on retention, efflclency and peak symmetry are umsldercd for reversed-phase liquid chromatography (RPLC) on octadecyl-modified ska (ODS) columns A number of factors are d~ussed, which make the systematic exploltatlon of pH effects m RPLC more comphcated than the optmuzatlon of solvent composltlon If the pH 1s vaned, a second factor (usually the concentration of orgamc modlfler) \ki111need to be vaned sunultaneously to mamtam retention (capacity factors) m the optunum range When pH is considered as a parameter m RPLC, not only its effects on retention, but also the vanatlons m efflclency (plate count) and peak shape (asymmetry) need to be considered These parameters turn out to vary drastically between mldual solutes and between different expenmental conhons The results of a study mvolvmg a number of acuk, basic and neutral solutes, two different ODS columns and nuxtures of either methanol or acetomtrde urlth aqueous buffers are reported