Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is being used more than ever for research and in laboratories to perform hormone tests, drug and toxicology analyses, screening for or confirmation of inherited metabolic diseases, and more. However, it can also produce aberrant or inaccurate results, requiring the lab to investigate what caused the anomaly or error. AACC’s Clinical Chemistry Series, developed in conjunction with the editors of Clinical Chemistry, will offer two webinars in May that focus exclusively on LC-MS/MS. Daniel Holmes, MD, clinical associate professor of pathology and laboratory medicine at the University of British Columbia and division head of clinical chemistry at St. Paul's Hospital, in Vancouver, BC, Canada, will host the second webinar, “Detecting and Managing Interferences and Contamination in Mass Spectrometric Analysis.”

Holmes will address how to systematically check for interferences in your LC-MS/MS assay, when and how to perform spiking experiments and associated calculations, and unexpected compounds in so-called pure materials—how to detect them and what to do about them. He’ll also discuss how tube selection and other preanalytical variables can affect your analyses, why peak review and ion ratios are your friends, and how to manage curveballs you may encounter from lot-specific interferences and contamination.

“I want to teach the audience that they need to be very cautious about checking for interferences in steroid assay development. I will be discussing some well-known ‘gotchas’—like gel tube interference,” Holmes told CLN Stat. “Importantly, it is unlikely for an interference to affect two multiple reactions equally, and so multiple reaction ratio monitoring becomes—to my mind—a mandatory part of results review. Peak review helps a whole lot also.” Holmes told CLN Stat he plans to cover “spiking experiments to prove the presence or absence of interference and the fact that the pure material of the potential interference can actually contain your analyte, which is frustrating,” and he will provide examples.

Additionally, “I will show an example of contamination and how it can be frustrating to ferret out—and how you can have a forehead-slapping moment when you find it,” Holmes explained.

The cost to attend the webinar, worth 1 ACCENT credit, is $99 for AACC members and $150 for non-members.