Until recently, little guidance existed on post-implementation monitoring of liquid chromatography-tandem mass spectrometry (LC-MS/MS) for clinical diagnostics, writes Kara L. Lynch, PhD, in the May issue of CLN.

Although labs often apply general quality measures used for routine testing to LC-MS/MS, they may need to take additional steps “to ensure that the time and effort they spend developing a reliable LC-MS/MS method is not wasted after implementation when they have difficulties maintaining quality,” advises Lynch, an assistant clinical professor and associate division chief of the clinical chemistry and toxicology laboratory at the University of California, San Francisco. 

To operate successfully, a versatile quality management system needs strong quality control and quality assurance protocols. “A guiding principle of QA plans is that they be proactive—not reactive. For LC-MS/MS methods, labs must be vigilant and ensure that they catch potential problems before quality becomes compromised. LC-MS/MS quality depends first on developing and verifying an accurate and robust method,” writes Lynch. 

A number of established guidelines have been published to assist labs in developing best quality methods for LC-MS/MS: the Clinical and Laboratory Standards Institute’s CLSI-C62A; the Food and Drug Administration’s Bioanalytical Method Validation; the European Medicines Agency’s Guideline on Bioanalytical Method Validation, and the Scientific Working Group for Forensic Toxicology Standard Practices for Method Validation. 

“While these offer ample guidance for development, it’s surprising that only CLSI-C62A provides best practices for QA and post-implementation monitoring,” Lynch observes. 

To establish an “intelligent” QA design for LC-MS/MS testing, labs should start with plans that cover sample analysis performance and instrument and assay performance over time, she writes. 

It’s imperative that labs monitor assay performance on a continuous basis, Lynch emphasizes. 

“An LC-MS/MS QA plan should include procedures for daily, weekly, and periodic instrument maintenance. Special considerations to ensure optimal instrument performance for LC-MS/MS methods include monitoring the number of column injections and the vacuum and LC pressures,” she writes. 

Pick up the May issue of CLN and learn more about intelligently designed QA plans for LC-MS/MS, and how they can markedly reduce instrument and method downtime