MSACL 2016 EU Abstract

Surviving Matrix Effects Experiments: PART 1

Grace van der Gugten (Presenter)
St Paul's Hospital

Authorship: Grace van der Gugten
St. Paul’s Hospital, Department of Pathology and Laboratory Medicine, Vancouver, Canada

Short Abstract

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is highly specific and sensitive, allowing for the measurement of endogenous compounds such as steroids and proteins, and xenobiotics and their metabolites in biological matrices. However, biological matrices are “dirty”, containing a vast spectrum of potentially interfering compounds which can cause problems for LC-MS/MS analysis suppressing or enhancing signal of the analyte(s) of interest: generically referred to as ‘matrix effects’. This presentation will describe matrix effects in detail, discuss the qualitative and quantitative matrix effects experiments, and give examples of each type of experiment.

Long Abstract

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is highly specific and sensitive, allowing for the measurement of endogenous compounds such as steroids and proteins, and xenobiotics and their metabolites in biological matrices. However, biological matrices are “dirty”, containing a vast spectrum of potentially interfering compounds, many of which can be co-extracted during the sample preparation process. These compounds can cause problems for LC-MS/MS analysis suppressing or enhancing signal of the analyte(s) of interest: these phenomena are generically referred to as ‘matrix effects’. These matrix effects must be assessed during LC-MS/MS method development and validation.

Post-column infusion and phospholipid transition monitoring are techniques to qualitatively assess matrix effects. The post column infusion visually demonstrates areas of ion suppression in the LC gradient. Phospholipid transition monitoring shows where phospholipids elute during the chromatographic run. These visual qualitative assessments can indicate if the extraction procedure or LC method need further development.

Quantitative matrix effects spiking experiments are the determination of the percentage of losses or gains of signal as a result of ion suppression or enhancement from co-extracted matrix compounds. This experiment was introduced in 2003 by Matuszewski [1] and consists of spiking pre and post extraction and using the results along with non-extracted samples to calculate % matrix effect. Even for those of us who have done many quantitative matrix effects experiments, the calculations for the concentration of analyte in the pre and post spiked samples can be challenging.

This presentation will describe matrix effects in detail, discuss the qualitative and quantitative matrix effects experiments, and give examples of each type. Detailed examples of the quantitative matrix effects pre and post spike calculations as well as results from matrix effects experiments performed in our laboratory will be shown.


References & Acknowledgements:

[1] Matuszewski B K et al. Strategies for the Assessment of Matrix Effect in Quantitative Bioanalytical Methods Based on HPLC-MS/MS. Anal Chem 2003; 75: 3019-3030


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