Monolithic Spin Column Extraction in LC‐MS Bioanalysis

Recently, microextraction by packed conventional sorbents in column or tip format has been developed and used for extraction of analyte(s) of interest from biological samples. The technique is effective in extracting analyte(s) from small sample volumes; however, the amount of the analyte(s) extracted is dependent on the amount of conventional sorbents packed, which limits the application of the microextraction. Therefore, a technique that is suitable for the extraction of analyte(s) of interest with a wide concentration range in complex biological samples is desirable. With this regard, microextraction with spin column packed with monolithic materials has become one of the most interesting techniques because of the high capacity of the monolithic materials. By using this technique, the analyte(s) of interest with a wide concentration rage in biological samples can be extracted with a small amount of the monolithic materials packed and eluted with a small volume of a solvent. Furthermore, all of the extraction steps, such as sample loading, washing, and elution, can be carried out by only centrifugation with a significantly reduced overall sample processing time for high throughput LC-MS bioanalysis.