January 2002 Meeting Announcement, Delaware Valley Mass Spectrometry Discussion Group
- Topic: "High Turbulence Liquid Chromatography and Tandem Mass Spectrometry in the Clinical Laboratory."
- Speaker: Michael Caulfield, Quest Diagnostics Nichols Institute, San Juan Capistrano, California.
- Date: Wednesday, January 9, 2002. 7:00 PM
- Time: Social Hour: 7:00 PM.
Talk: 7:30 PM.
- Place: Merck, West Point, 37 Auditorium
- Abstract: Quest Diagnostics is constantly striving to improve diagnostic testing to provide better patient care. HPLC with conventional detectors such as UV or fluorescence are prone to problems of interfering substances. Immunoassays, such as radioimmune assay (RIA), also have potential cross-reactivity with therapeutic drugs. Nichols Institute has initiated a program to develop new methods on the tandem mass spectrometer to replace current HPLC and immunoassays of small molecules to address these problems. Urinary free cortisol (UFF) is used extensively in the diagnosis of Cushing's disease and was the first HPLC assay to be converted. An HPLC assay of 150-200 samples took 36 to 48 hrs to complete and required approximately 15-20% of samples to be repeated due to some form of interference. Combining the Cohesive High Turbulence Liquid Chromatography (HTLC) system with the API 2000 a method was developed for UFF which requires minimal sample manipulation because extractions are performed on-line. The UFF method using a single HTLC unit takes 5.25 min per sample. Using the Cohesive TX-4 system (4 HTLC units working in concert) a sample result is obtained every 1.2 min and 150-200 samples can be analyzed within 8 hrs with a repeat rate of < 2%. Other assays, testosterone and fractionated bile acids, using the HTLC system with the tandem mass spectrometer (HTLCMSMS) have also been developed and will be discussed. The availability of robust instruments that can perform sample analysis in as little as one minute have made the use of tandem mass spectrometry a practical alternative to current methods of detection. The tandem mass spectrometer coupled with the on-line extraction of the HTLC offers a methodology that results in positive analyte identification and quantification as well as the ability to screen for interfering substances. This change in platform significantly improves the information provided to the physician to enhance patient care. Quest Diagnostics Nichols Institute foresees HTLCMSMS technology expanding to other Quest Diagnostics laboratories as it strives to improve patient care.
- Bio: Michael Caulfield received his Ph.D. in Biochemistry / Microbiology from
Bristol University (Bristol, England) in 1978. Following his postdoctoral
studies Michael has held positions at Harvard Medical School, Merck at West
Point, and Nichols Institute in California. Currently he is the Scientific
Director for Endocrinology and Metabolism at Quest Diagnostics Nichols
Institute, San Juan Capistrano, CA. His recent publications reflect his
long-term interest in calcium metabolism, parathyroid hormone, and
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