HPLC Separation of Chlorate and Bromate Ions
Primesep B2 separates chlorate and bromate by an ion-exchange mechanism. The anion-exchange properties of the column allow retention of hydrophilic compounds, and these properties can be adjusted by simply changing the ammonium formate buffer concentration. The HPLC separation uses a mobile phase of water, acetonitrile (MeCN, ACN) and ammonium formate with evaporative light scattering detection (ELSD).
BromateChlorateSodium BromateSodium Chlorate
HPLC Analysis of Basic Drugs and Acidic Counter-Ions by Mixed-Mode Chromatography
The majority of drugs in the pharmaceutical industry are administered in salt form. The presence of two counter-ions very often necessitates the use of two methods. The nature of these counterparts in drugs can be an inorganic cation and organic acid, inorganic anion and organic base, and organic cation and organic anion. Furthermore, the properties of the molecules will result in a differing stoichiometry. The task of simultaneous quantitation of counter-ions can be achieved by using mixed-mode columns. The general approach for analysis is based on properties of corresponding counter-ions. Hydrophobic basic drugs, like dextromethorphan, verapamil, trimipramine, and corresponding acidic counter-ions (chloride, chlorate, bromide, bromate, perchlorate, maleate, fumarate,tartrate, succinate, phosphate, citrate, benzosulfonate, toleuensulfonate) can be separated and quantitated in the same run on reversed-phase anion-exchange column. Basic hydrophobic drugs are retained by the reversed-phase mechanism, and counter-ions are retained by the reversed-phase and anion-exchange mechanism. Some polar counter-ions are retained only by the anion-exchange mechanism. Retention time and selectivity of HPLC separation of drugs and counter-ions can be achieved by changing the amount of acetonitrile and the amount of ions in the mobile phase. The detection technique depends on the properties of the counter-ions. In case of low or no UV activity, ELSD can be employed if the counter-ion forms a non-volatile salt with the mobile phase additive (ammonium formate). This HPLC method can be used for simultaneous quantitation of other basic drugs and counter-ions. The presence of two mechanisms of retention allows control over retention times of drug and counter-ion independently, and even allows a change of order of elution when necessary.
Benzenesulfonic AcidBromideChlorateChlorideCitric AcidDextromethorphanFumaric AcidMaleic AcidOrganic AcidsPerchloratePhosphoric AcidPyrilamineSuccinic AcidTartaric AcidVerapamilp-Toluenesulfonic Acid (PTSA)
Separation of Chlorate, Perchlorate, and Phosphonate Ions
The ionic forms of Chlorate, Perchlorate, and Phosphonates are useful in many industries including medicine, paper and use in explosives. Due to their lack of UV activity, an ELSD was used to detect both the anions and cations of all three sodium salts. The ions were retained on both Primesep D and Obelisc R columns. Primesep D is a reverse phase column with embedded basic ion-pairing groups. Obelisc R is also a reverse phase column, but can be additionally tuned due to embedded ionic groups and a hydrophobic chain.