Evaluation of a sensitive GC-MS method to detect polysorbate 80 in vaccine preparation

Polysorbates are the most versatile and common surfactants used as protein stabilizers. Analysis of residual polysorbate 80 (PS 80) in conjugate vaccine is challenging due to complexity of conjugate matrices and heterogeneity of the structure of the PS 80 analyte. The direct approach using high-performance liquid chromatography-evaporative light scattering detector (HPLC-ELSD) and gas chromatography-mass spectrometry (GC-MS) that is based on oleic acid methyl ester formation followed by transesterification have been evaluated to quantitate residual PS 80 in meningococcal serogroups A, C, W, Y and X bulk conjugates. HPLC-ELSD method was observed to be less sensitive in comparison to the GC-MS method. The GC-MS method showed promise for quantitation of residual polysorbate 80 with advantages of higher sensitivity, simple sample preparation and mass spectral characterization compared to methods reported to literature. The oleic acid methyl ester was solubilized in hexane and injected in GC-MS to separate on highly polar capillary CP-WAX 52 CB Column. The mass spectral analysis showed characteristic ions at m/z 180, 222 and 264. The method was validated with linearity r² > 0.99 over the concentration range of 0.5 to 100 μg/mL with LOD and LOQ of 0.3 and 0.91 respectively using PS 80 standard. The GC-MS method provides a simple, fast and label free technique for the precise quantitation of residual PS 80 in meningococcal bulk conjugate vaccine sample, achieved with accuracy between 85-105%.