convertMtime: Convert migration times to effective mobility

In rformassspectrometry/MetaboCoreUtils: Core Utils for Metabolomics Data

Convert migration times to effective mobility

Description

convertMtime performs effective mobility scale transformation of CE(-MS) data, which is used to overcome variations of the migration times, caused by differences in the Electroosmotic Flow (EOF) between different runs. In order to monitor the EOF and perform the transformation, neutral or charged EOF markers are spiked into the sample before analysis. The information of the EOF markers (migration time and effective mobility) will be then used to perform the effective mobility transformation of the migration time scale.

Usage

convertMtime(
  x = numeric(),
  rtime = numeric(),
  mobility = numeric(),
  tR = 0,
  U = numeric(),
  L = numeric()
)

Arguments

x	numeric vector with migration times in minutes.
rtime	numeric vector that holds the migration times (in minutes) of either one or two EOF markers in the same run of which the migration time is going to be transformed.
mobility	numeric vector containing the respective effective mobility (in in mm^2 / (kV * min)) of the EOF markers. If two markers are used, one is expected to be the neutral marker, i.e. having a mobility of 0.
tR	numeric a single value that defines the time (in minutes) of the electrical field ramp. The default is 0.
U	numeric a single value that defines the voltage (in kV) applied. Note that for reversed polarity CE mode a negative value is needed. Is only used if the transformation is performed based on a single marker.
L	numeric a single value that defines the total length (in mm) of the capillary that was used for CE(-MS) analysis. Is only used if the transformation is performed based on a single marker.

Value

numeric vector of same length as x with effective mobility values.

Author(s)

Liesa Salzer

Examples

 rtime <- c(10,20,30,40,50,60,70,80,90,100)
 marker_rt <-  c(20,80)
 mobility <- c(0, 2000)
 convertMtime(rtime, marker_rt, mobility)

rformassspectrometry/MetaboCoreUtils documentation built on Oct. 2, 2024, 5:13 a.m.