Adduct list

Description

List of common adducts observed for ESI-MS measurements in soft positive and negative ionization modes.

Usage

1

Format

A data frame with 47 observations on the following 6 variables.

Name

Adduct name

calc

Equation for calculating adduct m/z from uncharged non-adduct molecular mass M (m/z = M/z + X)

Charge

z

Mult

1/z

Mass

X

Ion_mode

Ionization mode (positive or negative)

Formula_add

Adduct chemical formula to be added

Formula_ded

Adduct chemical formula to be subtracted

Multi

Factor to multiply chemical formula with

Details

The correct way to calculate the isotopic pattern of a specific adduct is the following. First, multiply the chemical formula of the molecule by the times it appears in the final adduct; multiform. Second, add the chemical formula of any adduct to that of the molecule; mergeform. Third, subtract the chemical formula of any deduct from that of the molecule; check_ded & subform. Finally, calculate the isotopic fine structure using the correct charge argument in isopattern.

Note

Chemical formulas must conform to what is described in check_chemform.

Source

http://fiehnlab.ucdavis.edu/staff/kind/Metabolomics/MS-Adduct-Calculator/

References

Huang N., Siegel M.M., Kruppa G.H., Laukien F.H., J. Am. Soc. Mass. Spectrom. 1999, 10. Automation of a Fourier transform ion cyclotron resonance mass spectrometer for acquisition, analysis, and e-mailing of high-resolution exact-mass electrospray ionization mass spectral data

See Also

multiform mergeform check_ded subform

Examples

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# example of M+H adduct batch calculation
data(adducts)
data(isotopes)
data(chemforms)
# (1) check formulas for consistency - recommended
checked_chemforms <-	check_chemform(isotopes, chemforms)			 
# (2) multiply, see column 4 of adducts
chemforms <-multiform(checked_chemforms[,2],1)			 
# (3) add adduct - see column 7 of adducts
chemforms<-mergeform(chemforms,"H1")
# (4) calculate fine structure
patterns <- isopattern(isotopes, chemforms)