PICor: Statistical Isotope Correction

ICor is a python package for correcting mass spectrometry data for the effect of natural isotope abundance.

Description

PICor takes pandas DataFrames of the measured integrated MS intensities as input, corrects them for natural isotope abundance and returns a DataFrame again.

PICor can also correct for overlapping isotopologues due to too low resoltion.For example the 13-C4 and 2-H4 isotopologues of the metabolite NAD can't be resolved at a resolution of 60,000 at 200 m/z.

Installation

To install:

$ pip install picor

You need to have pandas and scipy installed.

Usage

After importing PICor and loading your data (for example a csv file) with pandas you the correction works with:

import pandas as pd
import picor

raw_data = pd.read_csv("data.csv", index="Time in h"))
corr_data = picor.calc_isotopologue_correction(
	raw_data,
	"NAD",
	)
print(corr_data)

You can activate a resolution depent correction by setting resolution_correction to True. Specify the resolution and the reference m/z ratio with resolution and mz_calibration.

Jørn Dietze, UiT - The Arctic University of Tromsø, 2020