Principles, current applications, and future perspectives of liquid chromatography-mass spectrometry in clinical chemistry

Applications of LC-MS to clinical chemistry have evolved considerably since the first use of LC-MS in clinical research facilities and in the routine of clinical laboratories. LC-MS is entering clinical specialties such as metabolic disorders, endocrinology, and therapeutic drug monitoring. Small molecules that pose challenges for the detection with conventional immunoassays are conversely suitable targets of the LC-MS detection. LC-MS meets the criteria of wide dynamic concentration ranges and flexibility required in the future approaches of clinical chemistry. However, a limited number of validated and approved LC-MS assays are currently available. This chapter covers several aspects of the LC-MS- based assays, from sample manipulation, to separation strategies, to detection methodologies, that can be generalized to many areas of clinical LC-MS applications.