The primary goal of this project was to evaluate a novel direct sample introduction time-of-flight (TOF) mass spectrometer (JEOL USA, Inc. AccuTOF-DART) for screening postmortem toxicology cases.
The evalution found that, instrument is promising, because the very rapid sample analysis and potential broad sensitivity warrant efforts to improve sensitivity and the software. Early data indicate that this technology has advantages for postmortem toxicology analyses. These include minimal sample preparation, thus saving labor and improving sample integrity, and a broader ability to detect a range of compounds than is currently possible for most technologies. An evaluation of the instrument’s ability to detect 112 different drugs and metabolites of interest in postmortem toxicology found that most drugs could be detected, but that detection limits were too high to see likely therapeutic levels of many drugs. An examination of these compounds in urine again found that many drugs were detectable, but that detection limits were not sufficient for concentrations encountered. In blood and tissues, a similar pattern was observed. Interferences were encountered from isomers, which cannot be distinguished by exact mass, possibly unresolved compounds affecting mass determination, and other matrix components interfering with ionization. The project also evaluated an autosampler that greatly aided sample handling and contributed to the consistency of results. The JEOL, USA Inc. AccuTOF-DART is a well-constructed instrument that is easily maintained and is very robust; however, the software (Mass Center) is unstable and does not perform in a standard Windows fashion; it is problematic for forensic handling of data. Based on these findings, the instrument is currently useful for rapid screening of samples for which sensitivity is not a concern, such as drug chemistries. Further work to improve the instrument’s sensitivity and software could result in a useful instrument for biological samples and other applications. 25 figures, 15 tables, 14 references, and appended Methanolic Drug Standards and data on drugs in urine and in blood