Tandem Mass SpectrometryNewborn ScreeningQuality Assurance and Control课件.ppt

Tandem Mass SpectrometryNewborn Screening Quality Assurance and Control Instrument and Method Validation Gary Hoffman Wisconsin Newborn Screening Laboratory State Laboratory of Hygiene Madison WI Training Issues Instrument vendor site training - Instrument operation Instrument troubleshooting Visit other MS/MS laboratories - 20 + MS/MS testing programs - spit equally between vendors APHL and NNSGRC sponsored courses - Baylor Institute of Metabolic Diseases - Duke Medical Center Write standard operating procedure Develop training and competency logs Instrument Performance Issues Mass Calibration Establish operating range of instrument Typical mass range 59 mu to 1800 mu Materials used Polypropylene (PPG) NaI / RbI solution Instrument Performance Issues Unit Resolution MS/MS unit resolution voltages 0.7 of a mass unit at 50% peak height Frequency Initial instrument set up Schedules vary Instrument Performance Issues Sample loop size Provides consistent injection volumes Best results when loop size equals injection volume. Typical loop sizes used 10 - 30 μL Probe rinses Minimize Carryover Instrument Performance Issues Detection Optimization Front End (ESI, cone, orifice, ring) voltages. Allows analyte ionization Minimize fragmentation Collision chamber, 2nd quadrapole, detector voltages Maximize output response detector voltage decrease needs adjustment. Instrument Performance Issues State files Mass calibration Voltages for each experiment (precursor ion, neutral loss, MRM) Method files Scan Parameters Analytical run time Help minimize carryover Long enough to return to baseline Typical run times: 1.5 to 3.0 minutes/specimen Instrument Performance Issues Data Reduction Software Calibration Table Analyte internal standard masses Designates which masses will be calculated from with in