|SOFT - TIAFT 1998||Poster Session 4||Friday October 9, 1998|
CHEMICAL DERIVATIZATION AND THE SELECTION OF DEUTERATED INTERNAL STANDARDS FOR QUANTITATIVE DETERMINATION: METHAMPHETAMINE EXAMPLE|
Dong-Liang Lin1, Tsung-Li Kuo2, Wei-Tun Chang3,4, and Ray H. Liu4
1. Ministry of Justice Bureau of Investigation, Taipei, Taiwan;
|Methamphetamine (MA) was selected as the exemplar compound to demonstrate that the most suitable deuterated analog to serve as the internal standard (IS) varies with the adopted derivatization group. Trimethylsilyl (TMS), trichloroacetyl (TCA), and pentafluoropropionyl (PFP) groups and d5-, d8-, and d9-MA were included in this study. Internal standards were purchased from Radian Corp.
Full-scan mass spectra data were used for preliminary selections of candidate ions for selected ion monitoring (SIM) for an analytical protocol. SIM data were then used to calculate the extent, if any, of contribution (by the IS under examination) to the intensity of ions designated for the analyte. Similarly, potential contributions by the analyte to the intensity of ions designated for the IS were also examined. Based on the resulting cross-contribution data shown in the following table, PFP derivatization using d9-MA appears to provide the more number of ions with least cross-contributions. d8-MA also provides good results.