Development of Direct Serial Coupling of Hydrophilic Interaction Liquid Chromatography and Reversed-Phase Columns for the Simultaneous Analysis of Anti-Tuberculosis Drugs

The use of HPLC-MS and -UV systems are preferred methods for the detection of pharmaceutical drugs. In this study, direct serial coupling of HILIC to a reversed-phase column via a zero-volume union was applied to resolve a mixture of first-line anti-tuberculosis drugs, including rifampicin (RIF), isoniazid (INH), pyrazinamide (PZA), ethambutol (EMB), and streptomycin (STP). These analytes, detected by either UV or MS, were chosen for their wide range of polarities and their analysis was achieved in a single HPLC injection with a 16 min runtime per sample and a flow rate of 0.6 mL/min. In addition, optimization of the chromatographic conditions required to separate the antibiotics in the direct serial coupling setup are also discussed.