Monitoring leachables from single-use bioreactor bags for mammalian cell culture by dispersive liquid-liquid microextraction followed by ultra high performance liquid chromatography quadrupole time of flight mass spectrometry

- DLLME as extraction technique for determination of leachables from single-use bags.
- Sample treatment was optimised using design of experiments (Box-Behnken design).
- DLLME is an ideal solution for leachable preconcentration and matrix simplification.
- UHPLC-QToF-MS was used for the identification of leachables from single-use bags.
- Analytical method was validated for determination of antioxidants in culture media.

A method for the identification of leachables in chemically defined media for CHO cell culture using dispersive liquid-liquid microextraction (DLLME) and UHPLC-MS is described. A Box-Behnken design of experiments (DoE) approach was applied to obtain the optimum extraction conditions of the target analytes. Performance of DLLME as extraction technique was studied by comparison of two commercial chemically defined media for CHO cell culture. General extraction conditions for any group of leachables, regardless of their specific chemical functionalities can be applied and similar optimum conditions were obtained with the two media. Extraction efficiency and matrix effects were determined. The method was validated using matrix-matched standard calibration followed by recovery assays with spiked samples. Finally, cell culture media was incubated in 7 single use bioreactors (SUBs) from different vendors and analysed. TBPP was not detected in any of the samples, whereas DtBP and TBPP-ox were found in all samples, with bDtBPP detected in six SUBs. This method can be used for early identification of non-satisfactory SUB films for cultivation of CHO cell lines for biopharmaceutical production.