A computer program to simplify analysis of mass scan data of organometallic compounds from high resolution mass spectrometers.

RATIONALE: Software accompanying High Resolution Mass Spectrometers (HRMS), particularly that used for the analysis of organometallic compounds, has lagged the technology of the instruments themselves. We have developed a computer program that partially fills this gap.

METHODS: Given the user's expectation for the number of atoms of a target element likely to be in an ion, the program calculates isotopologue mass differences for combinations of that element's isotopes and their expected intensity ratios relative to the most abundant isotopologue. These values are compared with mass differences and intensity ratios found in the experimental mass scan data and these metrics feed into a four-factor scoring model which ranks the ions as to the likelihood of each containing the specified number of the target atoms. The program was tested using experimental data obtained for selenomethionine.

RESULTS: Across a broad range of sample concentrations, the program consistently ranked selenomethionine at or near the top of the list of ions that passed the screening and ranking process. Mass scan data files in excess of 24,000 records were analyzed in less than one second.

CONCLUSIONS: The program is quick and efficient at scanning voluminous experimental data files for the presence of ions containing the expected number of atoms of a target element. Best results were obtained the scarcer the target element and the more isotopes it comprised.