Detect Adducts in Mass Spectrometry Data — detect

This function identifies potential adduct pairs in mass spectrometry data based on mass differences and retention times.

Usage

detect_adducts(
  data,
  ppm_tolerance = 5,
  rt_tolerance = 0.1,
  ion_mode = "pos",
  adducts = NULL
)

Arguments

data: A data frame containing at least the columns RT (retention time in minutes) and MZ (mass-to-charge ratio).
ppm_tolerance: Mass accuracy tolerance in parts per million (ppm) for matching mass differences. Default is 5 ppm.
rt_tolerance: Retention time tolerance in minutes for considering peaks as potential adducts. Default is 0.1 minutes.
ion_mode: Ionization mode, either "pos" for positive or "neg" for negative. Default is "pos".
adducts: Optional data frame of adduct definitions. If not provided, a default list of common adducts is used based on ion_mode.

Value

A data frame of potential adduct pairs with details of the matches.

Examples

# Sample data
data <- data.frame(
  RT = c(1.0, 1.0, 1.0, 1.0),
  MZ = c(100.0000, 101.0073, 122.9892, 138.9632)
)
# Detect adducts in positive mode
results <- detect_adducts(data, ion_mode = "pos")
print(results)
#>   mz1 rt1      mz2 rt2 observed_diff  adduct theoretical_diff ppm_error
#> 1 100   1 122.9892   1       22.9892 [M+Na]+         22.98922 0.7829757
#> 2 100   1 138.9632   1       38.9632  [M+K]+         38.96316 1.0779414