Identify metabolites based on MS2 data.

identify_ms2_only(
  ms2.data,
  ms1.match.ppm = 25,
  ms2.match.ppm = 30,
  mz.ppm.thr = 400,
  ms2.match.tol = 0.5,
  fraction.weight = 0.3,
  dp.forward.weight = 0.6,
  dp.reverse.weight = 0.1,
  rt.match.tol = 30,
  polarity = c("positive", "negative"),
  ce = "all",
  column = c("hilic", "rp"),
  ms1.match.weight = 0.25,
  rt.match.weight = 0.25,
  ms2.match.weight = 0.5,
  path = ".",
  total.score.tol = 0.5,
  candidate.num = 3,
  database,
  threads = 3
)

Arguments

ms2.data

MS2 data, must be mgf, msp or mzXML format. For example, ms2.data = c("test.mgf", "test2.msp").

ms1.match.ppm

Precursor match ppm tolerance.

ms2.match.ppm

Fragment ion match ppm tolerance.

mz.ppm.thr

Accurate mass tolerance for m/z error calculation.

ms2.match.tol

MS2 match (MS2 similarity) tolerance.

fraction.weight

The weight for matched fragments.

dp.forward.weight

Forward dot product weight.

dp.reverse.weight

Reverse dot product weight.

rt.match.tol

RT match tolerance.

polarity

The polarity of data, "positive"or "negative".

ce

Collision energy. Please confirm the CE values in your database. Default is "all".

column

"hilic" (HILIC column) or "rp" (reverse phase).

ms1.match.weight

The weight of MS1 match for total score calculation.

rt.match.weight

The weight of RT match for total score calculation.

ms2.match.weight

The weight of MS2 match for total score calculation.

path

Work directory.

total.score.tol

Total score tolerance. The total score are refering to MS-DIAL.

candidate.num

The number of candidate.

database

MS2 database name or MS database.

threads

Number of threads

Value

A metIdentifyClass object.

See also

The example and demo data of this function can be found https://tidymass.github.io/metid/articles/metid.html

Author

Xiaotao Shen shenxt1990@outlook.com