Online Solid Phase Extraction and LC-MS Analysis of Thyroid Hormones in Human Serum

LC-MS has been reported to offer superior specificity and speed over the immunoassays for determination of thyroid hormones in biological matrices such as serum and tissues. Nevertheless, the reported sample preparation procedures, typically liquid-liquid extraction followed by solid phase extraction (SPE), involve multiple time consuming steps, and are less compatible with automation. The present work demonstrates successful online SPE with LC-MS for rapid determination of thyroid hormones in biological matrices.