Analysis of drugs in biological samples by direct injection method using the 'Co-sense for BA LCMS' system

摘要

In the studies of pharmacokinetics and metabolism, it is important to remove proteins from biological samples prior to instrumental analyses, and it is required to minimize labor in such deproteinization procedures. This report refers to the Shimadzu "Co-Sense for BA IC/MS" system, which has been specifically developed for direct analyses of drugs in plasma. This system is equipped with an automated sample pretreatment device using a Shim-pack MAYJ-ODS column packed with packing material of a restricted access media type. Sample pretreatment and analytical conditions are optimized so that high selectivity is ensured in mass spectrometry. The net results are high throughput analytical runs, including deproteinization and gradient LC analysis, can be conducted in a 5-minute cycle. Evaluation test using mixture solution of metoprolol, propranolol, lidocaine, dibucaine, and bupivacaine showed higher than 90 recovery, better than 3 repeatability, and better than 0.999 linearity. The entire IC/MS system is expected to ensure high reliability in routine analyses: chromatographic patterns showed only little variation in 300-time repetitive injections of a plasma sample spiked with target compounds. This report also refers to our studies to compare the Shim-pack MAYI-ODS column and a conventional pretreatment column, and to the development of a semi-micro IC/MS system.