Forensic science

U.S. initiatives to strengthen forensic science & international standards in forensic DNA

A number of initiatives are underway in the United States in response to the 2009 critique of forensic science by a National Academy of Sciences committee. This article provides a broad review of activities including efforts of the White House National Science and Technology Council Subcommittee on Forensic Science and a partnership between the Department of Justice (DOJ) and the National Institute of Standards and Technology (NIST) to create the National Commission on Forensic Science and the Organization of Scientific Area Committees. These initiatives are seeking to improve policies and practices of forensic science. Efforts to fund research activities and aid technology transition and training in forensic science are also covered. The second portion of the article reviews standards in place or in development around the world for forensic DNA. Documentary standards are used to help define written procedures to perform testing. Physical standards serve as reference materials for calibration and traceability purposes when testing is performed. Both documentary and physical standards enable reliable data comparison, and standard data formats and common markers or testing regions are crucial for effective data sharing. Core DNA markers provide a common framework and currency for constructing DNA databases with compatible data. Recent developments in expanding core DNA markers in Europe and the United States are discussed.

Simultaneous determination of amphetamine and one of its metabolites by HPLC with electrochemical detection

A high-performance liquid chromatographic method coupled with electrochemical detector was developed for the separation and quantitation of amphetamine and one of its metabolites, the 4-hydroxynorephedrine. The pre-column derivatisation of these compounds was carried out with 2,5-dihydroxybenzaldehyde as electroactive labelling reagent, in presence of Borohydride Exchange Resin. The new synthetic method developed was fast, clean and high yielding. The analysis was performed in isocratic mode on a reversed phase column 5 microm Hypersil ODS RP-18, 15 cm, using as a mobile phase methanol-NaH(2)PO(4) buffer (50 mM, pH 5.5)(30:70 v/v) containing trietylamine (0.5% v/v) and the products were detected by a porous graphite electrode set at an oxidation potential of +0.6 V. The linearity of response was examined for each derivatised compound and was analysed using solutions in the range 10-40 nmol/ml. The correlation coefficients of the linear regression of the standard curves were greater than 0.99. The method developed in this study was sensitive and very selective. Because of the specificity for primary phenylethylamines, it could be applicable for the assay of other related substances in toxicology and drugs abuse.

Fast analysis of drugs in a single hair

A new method for the fast screening of cocaine and 6-monoacetylmorphine (6-MAM) in a single hair, using gas chromatography/mass spectrometry (GC/MS), is described. The analyses are conducted in less than 10 min with minimal sample preparation. The novel method combines the ChromatoProbe direct sample introduction device for intrainjector thermal extraction, fast GC separation, a supersonic molecular beam GC/MS interface and hyperthermal surface ionization (HSI). The technique has been successfully employed for the detection of cocaine in as little as a 1-mm section of hair using selected ion monitoring (SIM). Unambiguous full scan mass spectra of cocaine and 6-MAM were obtained on a single hair for cocaine and heroin users, respectively. HSI was found to be almost 3 orders of magnitude more selective than electron impact ionization for cocaine compared with the major hair constituents, with a minimum detected concentration of approximately 10 ppb in the SIM mode. Results obtained for 12 drugs users showed full qualitative agreement with similar results using rigorous solvent extraction followed by electrospray-liquid chromatography/mass spectrometry analysis. However, quantitative studies showed only partial agreement. No false positives were observed for 10 drugs free subjects. This method enables fast drug monitoring along the hair length which permits time correlation studies.