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

1 |

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

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`

.

Chemical formulas must conform to what is described in `check_chemform`

.

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

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

`multiform`

`mergeform`

`check_ded`

`subform`

1 2 3 4 5 6 7 8 9 10 11 12 | ```
# 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)
``` |

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