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Evaluation of Laser Diode Thermal Desorption-Tandem Mass Spectrometry (LDTD-MS-MS) in Forensic Toxicology

NCJ Number
Date Published
October 2014
8 pages
N.D. Bynum, K.N. Moore, M. Grabenauer
This study used laser diode thermal desorption-tandem mass spectrometry (LDTD-MS-MS) to validate 48 compounds in drug-free human urine and blood for screening or quantitative analysis.
Many forensic laboratories experience backlogs due to increased drug-related cases. Laser diode thermal desorption (LDTD) has demonstrated its applicability in other scientific areas by providing data comparable with instrumentation, such as liquid chromatography-tandem mass spectrometry, in less time. In the current study, the performance of LDTD-MS-MS was determined by evaluating carryover, interference, limit of detection, limit of quantitation, matrix effect, linearity, precision, and accuracy and stability. Quantitative analysis indicated that LDTD-MS-MS produced precise and accurate results with the average overall within-run precision in urine and blood represented by a %CV <14.0 and <7.0, respectively. The accuracy for all drugs in urine ranged from 88.9 to 104.5 percent and 91.9 to 107.1 percent in blood. Overall, LDTD has the potential for use in forensic toxicology; however, before it can be successfully implemented, there are some challenges that must be addressed. Although the advantages of the LDTD system include minimal maintenance and rapid analysis (~10 s per sample), which makes it ideal for high-throughput forensic laboratories, a major disadvantage is its inability or difficulty in analyzing isomers and isobars due to the lack of chromatography without the use of high-resolution MS; therefore, it would be best implemented as a screening technique. (Publisher abstract modified)
Date Created: July 12, 2016