Development of a gas chromatography-mass spectrometry method for determination of β-propiolactone (BPL) residues in inactivated covid-19 vaccines

Abstract β-propiolactone (BPL) is a common inactivator agent used in vaccines. Due to BPL carcinogenicity, complete hydrolysis of it is necessary to prevent cytotoxicity in mammalian cells. As a result, more attention should be paid to it at the clinic and it is important to measure its trace amounts. BPL analysis is challenging due to its instability. A simple and fast gas chromatography-mass spectrometry (GC-MS) method was developed for quantitation of residual BPL in inactivated covid-19 vaccines. Caprolactone was used as internal standard in samples solutions, the analysis was performed after extraction of analyte from vaccine media by ethyl acetate. The validity of the method was studied with a linearity of r 2 > 0.99 over the concentration range of 0.2–20 µg/mL with the limit of detection and the limit of quantification of 0.68 and 2.06 µg/mL, respectively. The target analyte BPL was not detected in the samples, demonstrating the test samples were qualified. The established method can be used for quality control of inactivated covid-19 vaccines.