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Mass Spectrometry M/Z Ratio — FRCA Primary MCQ

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ModeratePhysics & Clinical MeasurementMass Spectrometry M/Z RatioFRCA Primary

In mass spectrometry used for gas analysis molecules are separated based on:

Educational content. Not a substitute for clinical judgement or local policy.

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Correct answer: B — Their mass-to-charge ratio

Mass spectrometry ionises gas molecules and accelerates them through a magnetic field. They are deflected according to their mass-to-charge ratio allowing identification and quantification. It can measure multiple gases simultaneously (O2 / CO2 / N2O / N2 / volatiles) with rapid response time. It is expensive and usually shared between multiple operating theatres via a sampling line.

Reference: Al-Shaikh Stacey 2019 Essentials of Anaesthetic Equipment