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interference_database.py

ICP-MS Interference Database for spICP-ToF-MS

Comprehensive database of known spectral interferences including: - Isobaric (same nominal mass from different elements) - Polyatomic / Argide (ArO+, ArAr+, ArN+, ArCl+, etc.) - Oxide (MO+, MOH+) - Chloride (MCl+) - Doubly-charged (M2+) - Nitride / Hydride adducts

Used for: 1. Per-particle interference diagnosis 2. Smart isotope auto-selection (scoring function) 3. Visual warnings in periodic table and plots

References: May & Wiedmeyer, Atomic Spectroscopy 19(5), 150-155 (1998) Thomas, Practical Guide to ICP-MS, 3rd Ed. (2013) Balcaen et al., Anal. Chim. Acta 894, 7-19 (2015)

Constants

Name Value
PLASMA_SPECIES frozenset({'Ar', 'O', 'N', 'H', 'C'})

Functions

get_interferences_for_mass

def get_interferences_for_mass(nominal_mass: int) → list

Get all known interferences for a given nominal mass.

Args:

  • nominal_mass: Integer nominal mass (e.g. 56 for 56Fe)

Returns:

  • List of interference dicts, empty if none known

get_particle_relevant_interferences

def get_particle_relevant_interferences(nominal_mass: int, elements_in_particle: Set[str]) → list

Get interferences that are plausible for a specific particle based on which elements were co-detected.

Plasma-based interferences (ArO+, Ar2+, etc.) are always included. Non-plasma interferences are only included if ALL required non-plasma components are present in the particle.

Args:

  • nominal_mass: Integer nominal mass being evaluated
  • elements_in_particle: Set of element symbols detected in this particle

Returns:

  • List of plausible interference dicts

get_worst_severity

def get_worst_severity(interferences: list) → str

Get the worst (most severe) interference severity from a list.

Args:

  • interferences: List of interference dicts

Returns:

  • 'critical', 'major', 'minor', or 'none'

has_any_interference

def has_any_interference(nominal_mass: int) → bool

Quick check if a nominal mass has any known interferences.

Args:

  • nominal_mass: Integer nominal mass

Returns:

  • True if interferences are known

score_isotope

def score_isotope(mass: float, abundance: float, interferences: list, abundance_weight: float = 1.0, interference_weight: float = 50.0, min_abundance: float = 0.5) → float

Score an isotope for auto-selection. Higher score = better choice.

The score balances abundance (we want high signal) against interference risk (we want clean measurements).

Score = abundance - (severity_penalty * interference_weight)

For isotopes below min_abundance, a heavy penalty is applied to avoid selecting isotopes with too little signal.

Args:

  • mass: Exact isotope mass
  • abundance: Natural abundance as percentage (0-100)
  • interferences: List of interference dicts for this mass
  • abundance_weight: Weight for abundance term (default 1.0)
  • interference_weight: Penalty weight per interference (default 50.0)
  • min_abundance: Minimum abundance % to consider (default 0.5)

Returns:

  • Float score (higher is better)

get_best_isotope

def get_best_isotope(element_data: dict, available_masses: list = None, abundance_weight: float = 1.0, interference_weight: float = 50.0, min_abundance: float = 0.5) → Optional[dict]

Select the best isotope for an element based on abundance and interference scoring.

Args:

  • element_data: Element dict from PeriodicTableWidget containing
  • 'symbol', 'isotopes' list
  • available_masses: Optional list of masses available in the data.
  • If provided, only isotopes matching available masses are
  • considered (tolerance 0.5 Da).
  • abundance_weight: Weight for abundance in scoring
  • interference_weight: Weight for interference penalty
  • min_abundance: Minimum abundance to consider

Returns:

  • Best isotope dict {'mass', 'abundance', 'label', 'score',
  • 'interferences'} or None if no isotopes available

build_smart_preferred_isotopes

def build_smart_preferred_isotopes(elements_data: list, available_masses: list = None) → dict

Build a complete preferred isotopes dictionary using smart scoring.

This replaces the hardcoded PREFERRED_ISOTOPES dict in IsotopeDisplay.

Args:

  • elements_data: List of element dicts from PeriodicTableWidget
  • available_masses: Optional list of available masses

Returns:

  • Dict mapping element symbol to preferred isotope label string
  • e.g. {'Ca': '44Ca', 'Fe': '57Fe', 'Au': '197Au'}

get_isotope_interference_summary

def get_isotope_interference_summary(element_data: dict, available_masses: list = None) → list

Get a summary of all isotopes for an element with their interference status, for display in the periodic table isotope panel.

Args:

  • element_data: Element dict from PeriodicTableWidget
  • available_masses: Optional list of available masses

Returns:

  • List of dicts with keys:
  • mass, abundance, label, nominal_mass,
  • has_interference, worst_severity, interferences, score
  • Sorted by mass.