Rehydration and restoration of fingerprint ridge detail in mummified post-mortem tissue: Literature review and investigation of a simplified formulation.

Mummified tissue presents challenges for fingerprinting due to rigidity, shrinkage, and other features obscuring epidermal ridge detail. A new cost-effective in-house solution was developed to obtain good quality fingerprints from mummified remains. The simplified procedure uses a sodium carbonate:sodium acetate mixture easily prepared using commonly available chemical products. An overview of the methods and solutions utilized to date for rehydration and restoration illustrates the main benefits of the developed formulation: the solution provided better tissue pliability and turgor than the sodium carbonate:ethanol formulation of Rüffer previously employed; the prepared solution proved stable for weeks at room temperature and poses minimum hazard risk to users. It functions as a weak base (pH 9.3) and is sufficiently corrosive to allow tissue softening over a flexible timeframe of 1-5 days without causing any damage. The degree of effectiveness for rehydration of mummified tissue and restoration of ridge detail is attributed to three synergistic aspects: increased turgor as provided by a penetrating humectant and water; softening and pliability as a result of pH and any specific chemical interaction that affects calcium in collagen; ridge detail definition as a function of turgor and softening, with some secondary corrosive dependency related to the pH of a solution.

Utilization of X-ray Computed Tomography for the Exclusion of a Specific Caliber and Bullet Type in a Living Shooting Victim.

A bystander claimed to have been shot by a police officer, and CT scans were used to match qualitative and quantitative aspects of the unremoved bullet with police issued 9 mm Luger ammunition. CT scan methodology proved a valid approach for the measurement of bullets based on calculated measurement capability and correlation with "gold standard" physical measurement by vernier caliper. Measurements regarding length and base diameter, as well as length/diameter ratio, were insufficient to unambiguously identify a specific caliber, or a bullet of specific mass within a caliber class. It was, however, possible to exclude a bullet of specific design and mass with well-characterized precision and accuracy values under selected CT scan conditions. A 9 mm Luger bullet (115 gr FMJ RN) was excluded from involvement in a shooting based on qualitative bullet shape combined with length, base, and ratio measurements of the bullet in-situ for the victim.

Rapid GC-MS confirmation of amphetamines in urine by extractive acylation.

Amphetamine and related derivatives are widely abused central- and psychostimulants. Detection of certain derivatives, such as methcathinone, by commonly available immunoassay screening techniques is insufficient. Multi-analyte confirmations for amphetamine type stimulants are therefore required, but traditional gas chromatography-mass spectrometry methods necessitate lengthy analytical procedures with prolonged sample turn-around times. A validated rapid GC-MS assay for urinary confirmation of amphetamine, methamphetamine, methcathinone, ephedrine, norephedrine, methylenedioxyamphetamine, methylenedioxymethamphetamine, methylenedioxyethylamphetamine and N-methyl-1-(3,4 methylenedioxyphenyl)-2-butanamine is reported. The method entailed in situ derivatization of urine specimens by extractive acylation with pentafluoropropionic anhydride, followed by rapid chromatography on a microbore capillary column. Analytes were separated in less than 3 min and quantified simultaneously by selected-ion monitoring using stable isotope substituted internal standards. The total instrument cycle-time was 6 min per sample. The limits of detection were between 1.5 ng/mL and 6.25 ng/mL for the various analytes. Intermediate precision and accuracy were in the range of 6.3-13.8% and 90.5-107.3% for the respective analytes at the lower limit of quantitation, and between 5.8-12.6% and 95.4-103.1% for the high control. Long-term storage of methcathinone positive specimens at -20 degrees C proved insufficient stability of this analyte. The proposed assay is precise and accurate for confirmation of amphetamine and derivatives in urine. The complementary approach of extractive-derivatization and fast GC-MS analysis is especially applicable in routine clinical settings where reduced sample turn-around times are required. Further investigation of cathinone as a possible metabolite of methcathinone is warranted, based on results from analyzed authentic urine samples.

Analysis of urinary biomarkers for exposure to alkyl benzenes by isotope dilution gas chromatography-mass spectrometry.

A validated GC-MS method for the analysis of urinary metabolites of alkyl benzenes is reported. Metabolites for exposure to toluene, xylene and ethylbenzene were analyzed simultaneously using stable isotope substituted internal standards. The method entailed acidic deconjugation of urine samples followed by extractive alkylation with pentafluorobenzyl bromide as alkylating agent. The resulting pentafluorobenzyl derivatives of ortho-, meta-, para-cresol, mandelic acid (MA), hippuric acid (HA) and ortho-, meta-, para-methylhippuric acid (MHA) were then quantified by SIM. Optimized reaction conditions for the extractive alkylation step are reported. The derivatives were found to be sufficiently stable for overnight batch analysis. The LODs were below 0.1 micromol/L for the cresols and below 1 micromol/L for MA and the HAs. Within-batch precision for o-MHA was 7%, for m-MHA 5%, for p-MHA 5.2% and below 5% for the rest of the analytes.