Chromatographic determination of polymerized impurities in meropenem

A method for the separation of polymerized impurities in meropenem has been developed by gel filtration chromatography (GFC). The chromatographic conditions included a Superdex peptide HR 10/30 column and the mobile phase consisting of 0.01 mol L−1 sodium phosphate buffer (pH 7.0), at a flow rate of 0.8 mL min−1. The wavelength of UV detector was set at 220 nm. The linear range was 0.08-10 μg (r = 0.9998); relative standard deviation (R.S.D.) = 0.5-1.5%; the LOD and LOQ were 2.4 and 12.4 ng, respectively. Specificity of the GFC was checked by switching the effluent of each peak on the GFC to a C18 trap column and analyzing the effluent by LC-MS. The result shows that for the determination of polymers, the gel filtration chromatography is a rather simple separation mode as compared to RPLC.