ABSTRACT
Bioequivalence Studies ................................................................................ 428 18.3 Bioequivalence Study of Carvedilol ............................................................ 429 18.4 Pharmacokinetics Studies of Donepezil, Loratadine, and Cetirizine ......... 429 18.5 Determination of Gabapentin in Human Plasma Using HILIC
with Tandem Mass Spectrometry ................................................................ 434 18.6 Pharmacokinetic Study of the Peptide Drug Taspoglutide ......................... 434 18.7 HILIC-ESI-MS/MS Method for the Quantitation of Polar Metabolites
of Acrylamide in Human Urine ................................................................... 436 18.8 HILIC-MS/MS Technique for Sensitive Monitoring of the Changes
of Urinary Estrogen Conjugates .................................................................. 437 18.9 Combination of HILIC-MS and RPLC-MS for Pro“ling Polar Urine
Metabolites .................................................................................................. 438 18.10 Quanti“cation of Methylmalonic Acid and Homocystein in Serum
and Urine with HILIC-MS .......................................................................... 441 References .............................................................................................................. 441
HILIC or hydrophilic interaction liquid chromatography (originally called hydrophilic interaction chromatography) is a liquid chromatographic technique for the separation of polar and hydrophilic compounds. The expression “aqueous normal phase” is another term that sometimes is used for this technique. Thus, in HILIC, we should have a column with a hydrophilic stationary phase and a solvent (eluent) composed of water, buffer, and a high concentration of a water-miscible organic solvent like acetonitrile or methanol. Typically, in HILIC applications, the mobile phase consists of acetonitrile at a concentration between 50% and 95% in an aqueous buffer such as ammonium formate or ammonium acetate. These buffers are soluble in organic solvents and are volatile, compatible with mass spectrometry (MS) or evaporative light scattering (ELSD) detectors that are used mostly in HILIC applications.
