Analysis of diesel particulate matter using electron monochromator-mass spectrometry, bacterial identification using mass spectrometry and lateral flow immunochromatography, and detection of levamisole as a cutting agent in patients using cocaine

Abstract

Three studies and one review involving analytical mass spectrometry and one article on rapid bacterial diagnostics are presented herein. Electron monochromator-mass spectrometry (EM-MS) literature is presented outlining the development history and relevant analytical applications including nitro compounds in cigarette smoke, resonance energy studies, explosives, and bacterial identification. Diesel particulate matter and the effect of antioxidant fuel additives on nitro polycyclic aromatic production during diesel engine operation was investigated using EM-MS. Results showed a strong correlation between production of 2,6-di-tert-butyl-4-nitrophenol (DBNP) and the addition of two antioxidant precursors to the fuel prior to combustion. No correlations were observed between DBNP production and engine load or speed. Results indicate that the role of fuel additives in combustion byproducts must be carefully considered. When using CaO as a matrix-replacement in matrix-assisted laser desorption/ionization mass spectrometry, fatty acids are cleaved from phospholipids in situ by laser-induced pyrolysis. Ten bacterial genera were investigated using CaO as a matrix. Fatty acid profiles were observed and exported for statistical analysis. Principal components analysis of fatty acid profiles revealed distinct separation of bacterial genera. Cross-validation resulted in greater than 94% correct assignment. Future applications could provide clinicians a rapid and reliable method of bacterial detection. Outbreaks of infectious bacteria and concerns over bioterrorism have increased the demand for methods of rapidly and easily detecting bacteria. A lateral flow immunoassay (LFI) device was developed to detect Bacillus anthracis indirectly by using gamma phage amplification. Phage-based LFI detection of B. anthracis Sterne was consistently observed within four and as little as two hours of the onset of phage amplification with a threshold sensitivity of 2.5 x 10[superscript 3] cfu/mL. Ease and speed of the device could find application in the field by military personnel. Finally, individuals admitted to a hospital following cocaine use showed symptoms of levamisole poisoning. Levamisole, an antihelminthic used in veterinary science and a known lacing/cutting agent for cocaine, was detected in urine samples from these patients. Tissue and blood samples were also analyzed, but no concentration was detected. While no direct correlation could be made between patient symptoms and levamisole, its presence in their urine is a strong indication that the cocaine had been cut/laced with levamisole.