NCJ Number
57778
Journal
Journal of Forensic Sciences Volume: 22 Issue: 4 Dated: (OCTOBER 1977) Pages: 741-747
Date Published
1977
Length
6 pages
Annotation
EXAMPLES OF THE METHODS FOR MASS SPECTRAL IDENTIFICATION OF DRUGS AND EXPLOSIVES THROUGH THE USE OF IMPACT (EI) MASS SPECTROMETRY AND CHEMICAL IONIZATION (CI) ARE DISCUSSED.
Abstract
THE INSTRUMENT USED IN THE EXPERIMENTAL PROCEDURE WAS A DUPONT 21-490 SINGLE FOCUSSING MASS SPECTROMETER EQUIPPED WITH A DUAL CI-EI SOURCE. DRUG AND EXPLOSIVE SAMPLES WERE DISSOLVED IN ACETONE AND INTRODUCED AS SOLUTIONS INTO THE SOLID PROBE OF THE SPECTROMETER. AFTER THE SOLVENT EVAPORATED, THE PROBE WAS INTRODUCED INTO ION SOURCE. SALTS WERE ALSO INTRODUCED AS SOLIDS INTO THE PROBE. THE EXPERIMENTAL METHOD CONSISTED OF THE FOLLOWING STEPS: (1) RECORDING A CI MASS SPECTRUM OF THE UNKNOWN COMPOUND ON AN OSCILLOGRAPHIC RECORDER, THEN PUTTING THE MASS IDENTIFICATION INTO A CENTRAL COMPUTER WHICH RESULTS IN A NORMALIZED LINE MASS SPECTRUM AND A TABLE LISTING OF MASSES AND NORMALIZED ABUNDANCES; (2) INTERPRETING THE MASS SPECTRUM AND COMPARING IT TO A LIBRARY OF CI MASS SPECTRA OF FORENSIC COMPOUNDS; AND (3) RECORDING THE EI MASS SPECTRUM TO GIVE A 'FINGERPRINT' OF THE COMPOUND. THIS FRAGMENTATION PATTERN CAN THEN BE MATCHED TO ONE OF THE COMPOUNDS ACCORDING TO ITS CHEMICAL STRUCTURE, WHICH WILL PROVIDE FINAL IDENTIFICATION. THE REPORT CONTAINS TECHNICAL DIAGRAMS AND DATA AND A LIST OF REFERENCES. (MJW)