RESUMO
BACKGROUND: TNO Triskelion has applied its general workflow for the development of quantitative LC-MS methods for proteins in biological matrices to the quantification of infliximab in rat serum using bottom up µLC-MS/MS. Results/methodology: The general workflow consists of sample purification, analyte processing and LC-MS analysis. In the development of a quantitative µLC-MS/MS method for infliximab in rat serum the analyte processing part and the LC-MS part were optimized, in order to meet the different sample requirements of µLC-MS as compared with UPLC-MS. Using the optimized µLC-MS/MS method the LOQ was 75 ng/ml. CONCLUSION: The present study showed that it is possible to gain sensitivity when going to smaller scale LC-MS (UPLC-MS to µLC-MS). Due to the combination of a modified sample preparation approach and the application of µLC-MS a lower LOQ could be achieved for infliximab compared with a previously developed UPLC-MS method.