Spectral Interference
Definition
In ICP-MS, an overlap between the mass of the target analyte and that of a polyatomic or isobaric ion from another element in the plasma, which must be identified and corrected to avoid false readings.
- Field
- ICP-MS trace-element analysis
- Cause
- Mass overlap with polyatomic or isobaric ions
- Consequence if uncorrected
- False elevated readings
- Correction approaches
- Collision/reaction cell, mathematical correction equations
Common questions
What is a common example of a spectral interference in ICP-MS?+
Argon chloride ions formed in the plasma can overlap the mass of arsenic-75, so a chloride-rich sample can produce an inflated arsenic signal unless a collision cell or correction equation removes the interference.
How does an analyst know a spectral interference is present?+
Analysts run interference check standards and monitor known problem masses, and an unexpectedly high reading that does not match other corroborating data prompts a check for polyatomic overlap before the result is reported.
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