Liquid chromatography of analgesic drugs on ion-exchange resins

Liquid chromatography of aromatic hydrocarbons on ion-exchange resins

“…High-pressure liquid chromatography (HPLC) with certain reverse-phase systems gave poor resolution of ATC from EATC (8, 9). Shorter analysis times and good resolution of ATC, EATC, TC, (4R)-tetracycline (ETC), and chlortetracycline have recently been reported by isocratic reverse-phase ion-pair HPLC (10) and by gradient-elution reverse-phase HPLC (11)•, however, no evidence was presented to rule out formation of ATC and EATC by partial dehydration of TC and ETC in the highly acidic mobile phases used. Reproducibility data were not given for the ion-pair system, but in the gradient method the relative standard deviation for EATC was only ±6%.…”

“…In our laboratory, we have studied the chromatography of various polar aromatic compounds on anionand cationexchange resins (11,12) and noted, among other effects, the effect of the resin counterions. We have now extended these studies to polycyclic aromatic hydrocarbons and a few of their chlorinated derivatives, using both anionand cation-exchange resins of the polystyrene type.…”

Liquid chromatographic analysis of analgesics on Amberlite XAD-7

“…Several investigators have used pellicular anion exchangers with aqueous buffers as eluents (12)(13)(14), and one group employed a pellicular cation exchanger (15). Walton et al (16) investigated the use of macroporous and conventional gel-type ion-exchange resins for the separation of several analgesics using electrolyte-free alcohol-water mobile phases. Caffeine, phenacetin, ASA, and acetaminophen mixtures have been separated on an octadecylsilyl bonded phase using acetonitrile-water mobile phase containing ammonium carbonate ( I 7 ) , and these four compounds plus salicylamide were analyzed on a column of pellicular silica gel using organic solvent mobile phases (18).…”

Analytical studies and applications of ferroin type chromogens immobilized by adsorption on a styrene-divinylbenzene copolymer

“…Ionic resins of the polystyrene type, closely related to XAD-2, also exhibit pronounced binding properties toward uncharged organic compounds. Various studies, particularly those by Walton and co-workers (10)(11)(12), have revealed that adsorption by polystyrene resins primarily involves the "solvent" action of the polymer matrix for the organic solutes. Ionic groups on the polymer matrix are of secondary importance; their major influence is to promote solvation and swelling of the resin.…”