|Molecular Weight||172.200 g/mol|
Benzenesulfonic and toluenesulfonic acids are organic acids used in pharmaceutical industry as counter-ions for basic drugs. Both acids are hydrophilic in nature with strong acidic properties. Obtaining separation, retention and good peak shape with traditional reversed-phase columns is a challenging task. We developed robust mixed-mode approach for separation of benzenesulfonic acid and p-toluenesulfonic acid on a Primesep D reversed-phase anion-exchange column. Elution of these compounds is controlled by the amount of ions in the mobile phase and amount of acetonitrile. Both compounds are separated within 4 minutes and can be monitored by UV, ELSD, CAD or LC/MS. This column can be also used to analyze hydrophobic basic drugs by reversed-phase cation-exclusion mechanisms.
Ionic liquid is an ionic compound which is liquid at room (or close to room) temperature. Most of the ionic liquids are in a dynamic equilibrium where at any time more than 99.99% of the liquid is made up of ionic, rather than molecular, species. Room-temperature ionic liquids consist of bulky cation (for example, substituted imidazolium) compounds. A wide range of anions is used as counter ions in ionic liquids: organic and inorganic anions such as chloride, iodide, tetrafluoroborate, hexafluorophosphate, bistriflimide, triflate, tosylate. Ionic liquids are widely used as solvents in organic reactions. When products are isolated from ionic liquids, they need to be analyzed for residual ionic liquid content.
Because both constituents of the ionic liquid are very different in terms of charge and hydrophobic properties, it is impossible to analyze entire ionic liquids by traditional chromatography. An effective and universal method for analysis of ionic liquids is developed on an Obelisc R HPLC column. Components on the ionic liquids are retained based on ionic and hydrophobic interactions. Obelisc R column has both positively and negatively charged ionic groups, making it possible to retain and separate cations and anions of ionic liquids on one column. Method can be used for quantitative of various ionic liquids containing organic and inorganic ions. Retention time of basic component can be effectively adjusted by pH, stronger anionic and hydrophobic counter-ions might require higher buffer concentration. Composition can be monitored by combination of UV and ELSD or by LC/MS.
Organic acids were separated on a HILIC/cation-exchange column in HILIC/anion-exclusion mode. This column can be used for analysis of polar compounds in HILIC mode. If compounds are ionizable, additional mode of interaction can be added (cation-exchange or anion-exclusion).