Development and validation of a liquid chromatography-mass spectrometry method for the determination of...

A new liquid chromatography-mass spectrometry (LC-MS) method is developed and validated for the identification and determination of novel 4,5-diazafluoren-9-one compound. The method employs a Waters XTerra RP-18 column (150 mmx4.6 mm, i.d. 5 microm) with a mobile phase comprised of a (50:50, v/v) mixture of deionized water containing 0.2% acetic acid (solvent A) and methanol (solvent B) at a flow rate of 1 mL/min, at 35 degrees C. The detection is performed with photodiode-array (PDA) set at 210-400 nm and single quadropole mass spectrometer with electrospray ionization (ESI) positive ion mode. The chromatographic separation is achieved in less than 3 min. The linearity is established over the concentration range of 0.1-0.5 mg/mL (r2=1.000). The mean RSD values for intra- and inter-day precision studies are <2%. The recovery of 4,5-diazafluoren-9-one ranged between 99.84 and 99.97%. The limits of detection and quantitation are determined to be 0.58 and 0.1 mg/mL, respectively.