Effect of eight solvents on ethanol analysis by Dräger 7110 Evidential breath analyzer

The Dr?ger 7110 MK III FIN Evidential breath analyzer is classified as a quantitative analyzer capable to provide sufficient evidence for establishing legal intoxication. The purpose of this study was to evaluate ethanol specificity of this instrument in the presence of other solvents. Effects of eight possible interfering compounds on ethanol analysis were determined in a procedure simulating a human breathing. Most of the compounds studied had either a negligible effect on ethanol analysis (acetone, methyl ethyl ketone, and methyl isobutyl ketone) or were detected in very low concentrations before influencing ethanol readings (methanol, ethyl acetate, and diethyl ether). However, 1-propanol and 2-propanol increased the ethanol readings significantly. Thus, Dr?ger ethanol readings should be interpreted carefully in the presence of propanol.     

Fourier-transformed infrared breath testing after ingestion of technical alcohol

The study aim was to evaluate the feasibility of a Fourier-transformed infrared (FT-IR) analyzer for out-of-laboratory use by screening the exhalations of inebriated individuals, and to determine analysis quality using common breath components and solvents. Each of the 35 inebriated participants gave an acceptable sample. Because of the metabolism of 2-propanol, the subjects exhaled high concentrations of acetone in addition to ethanol. Other volatile ingredients of technical ethanol products (methyl ethyl ketone, methyl isobutyl ketone, and 2-propanol) were also detected. The lower limits of quantification for the analyzed components ranged from 1.7 to 12 microg/L in simulated breath samples. The bias was +/-2% for ethanol and -11% for methanol. Within-day and between-day coefficients of variation were <1% for ethanol and <4% for methanol. The bias of ethanol and methanol analyses due to coexisting solvents ranged from -0.8 to +2.2% and from -5.6 to +2.9%, respectively. The FT-IR method proved suitable for use outside the laboratory and fulfilled the quality criteria for analysis of solvents in breath.     

Fingerprint detection on counterfeit US dollar banknotes: the importance of preliminary paper examination

Two seizures of counterfeit 100 US dollar bills related to the same indicative number were submitted for processing of latent fingerprints. On one group of notes, identifiable fingerprints could be detected by the routine application of amino acid reagents. In the second case, this technique gave no results, even on deliberately deposited prints. Fingerprints could be revealed, however, by cyanoacrylate fuming followed by magnetic powder. Comprehensive paper analysis showed that banknotes from both seizures differed remarkably by chemical composition as well as paper macroscopic properties. The difference in surface free energy (related to surface tension) of the banknotes in the two groups seemed to be the major factor responsible for the great variance in fingerprint detectability.