The double spike toolbox

Double spiking is a powerful way to correct for instrumental mass fractionation in mass spectrometry. One of the difficulties of the technique is choosing the double spike composition: by careful choice of the double spike composition, more precise measurements can be made. The aim of the double spike toolbox is to make this choice easier. The toolbox is a collection of MATLAB codes for performing double spike inversions and optimising double spike compositions for all isotope systems. The workings of the toolbox are described in detail in the following manuscript:

Rudge J.F., Reynolds B.C., Bourdon B. The double spike toolbox (2009) Chem. Geol. 265:420-431 [PDF Final] [PDF preprint] [Elsevier version]

To use the double spike toolbox, a recent version of MATLAB is required (it has been tested on MATLAB 7.1 (R14SP3) through to MATLAB 8.2 (2013b), but might also work with earlier versions). The Optimization and Statistics toolboxes are also required.

Software download: Latest version (1.01)

Installation instructions:

  1. Download and uncompress the doublespike.zip package.
  2. Add the doublespike folder to MATLAB’s path. (Using MATLAB’s menu: File->;Set Path ->; Add Folder.)
  3. Type ‘doc doublespike’ to view a brief tutorial (also available here) or ‘help doublespike’ for a list of commands.

Double spike cocktail lists: For the impatient, there are lists of optimal double spikes for all isotope systems available here (Excel spreadsheet). These were produced using the double spike toolbox, with some sensible choices of default parameters. See the manuscript for more details. Like all good recipies, they should be taken with a pinch of salt.

Please send any bug reports or suggestions for improvement to doublespike@johnrudge.com.