Post-analytical practices in clinical mass spectrometry laboratories: an international survey across 57 countries.

Objectives: Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is increasingly used in clinical laboratories due to its high analytical specificity and multiplexing capabilities. While the pre-analytical and analytical phases have seen significant advances in automation, the post-analytical phase remains a bottleneck with limited standardisation. This survey aimed to identify gaps, benchmark practices against guidelines, and inform recommendations for improving consistency and quality in post-analytical data handling.

Methods: A descriptive electronic survey with 53 questions was distributed via the IFCC mailing list and collaborating organisations from May to July 2024. Questions covered participant characteristics, post-analytical quality indicators (e.g., chromatograms, calibration curves, ion ratios), quality assurance, and data management. Responses were benchmarked against three LC-MS/MS guidelines.

Results: Of 311 initial responses, 203 valid submissions from 57 countries were analysed. Laboratories reported diverse throughput: low (<100 samples/week, n=50), medium (100-2,000 samples/week, n=125), and high (>2,000 samples/week, n=28). Key findings included inconsistent acceptance criteria (e.g., variable ion ratios and signal-to-noise thresholds), reliance on manual data transcription (38 % of laboratories), and continued use of in-house spreadsheets. Practices often deviated from guidelines, with opportunities identified for harmonisation and automation.

Conclusions: In collaboration with the clinical mass spectrometry community, the IFCC-ETD developed six key recommendations from this survey to address challenges and enhance consistency, quality, and efficiency in post-analytical data handling.