Evaluation of electrospray transport CID for the generation of searchable libraries

This paper reports the preliminary investigation of performance-based stand ard conditions that have been developed for electrospray ionization mass sp ectrometry. Using performance-based standard criteria, reproducible spectra can be obtained by CID in the electrospray-transport region and searched u sing a database created using the same performance criteria. To generate li brary-searchable mass spectra, the instrument was tuned to standard conditi ons that correspond to low, mid, and high fragmentation energies. The instr ument was tuned using ion ratios relative to a given peak in a tune compoun d for each energy level. The library was evaluated using a set of 22 benzod iazepines. The CID libraries were found to be reproducible, both on the sam e instrument and on different instruments of the same type. Also, the libra ries were found to be independent of now rate and solvent system. The libra ry was expanded to include 16 sulfonyl-urea herbicides and tested using spi ked water samples. Performance of the library was tested over a concentrati on range of 2 orders of magnitude using sulfonylurea standards.