A capillary column high-performance liquid chromatography (CapLC) method and a laser desorption ionization-time of flight (LDI-TOF)-MS method are described for the determination of quinapril, an angiotensin-converting enzyme inhibitor. Effective separation was achieved by using a C18 capillary column at a flow rate of 10 microL/min. For CapLC, quinapril and 7-hydroxycoumarin (internal standard) were detected at 210 and 320 nm, respectively. Phenformin replaced 7-hydroxycoumarin as the internal standard for the LDI-TOF-MS method successfully developed to detect quinapril. The calibration curves showed good linearity in the range of 1-100 micro/mL in these two methods. For high throughput purposes, the LDI-TOF-MS method was simpler and faster than the CapLC method. Both green methods were suitably validated and successfully applied to determine quinapril in commercial tablets.