Niamh Nic Daeid

Evaluation of six presumptive tests for blood, their specificity, sensitivity, and effect on high molecular-weight DNA

ABSTRACT: Luminol, leuchomalachite green, phenolphthalein, Hemastix®, Hemident™, and Bluestar© are all used as presumptive tests for blood. In this study, the tests were subjected to dilute blood (from 1:10,000 to 1:10,000,000), many common household substance, and chemicals. Samples were tested for DNA to determine whether the presumptive tests damaged or destroyed DNA. The DNA loci tested were D2S1338 and D19S433. Leuchomalachite green had a sensitivity of 1:10,000, while the remaining tests were able to detect blood to a dilution of 1:100,000. Substances tested include saliva, semen, potato, tomato, tomato sauce, tomato sauce with meat, red onion, red kidney bean, horseradish, 0.1 M ascorbic acid, 5% bleach, 10% cupric sulfate, 10% ferric sulfate, and 10% nickel chloride. Of all the substances tested, not one of the household items reacted with every test; however, the chemicals did. DNA was recovered and amplified from luminol, phenolphthalein, Hemastix®, and Bluestar©, but not from leuchomalachite green or Hemident™.

The rates and relative risks of workplace bullying in Ireland, a country of high economic growth

A National Survey of the work force in Ireland was carried out in July 1999. 6.2%; of respondents (N=1057) had been exposed to frequent bullying over the previous 12 months. Events involving significant change in their workplace environment coincided with the onset of bullying suggesting that change in workplace practice is a major factor in the onset of bullying. Growth rates for 22 occupational categories were calculated showing a wide range of increase and decline in the numbers (/100,000) of individuals working within these various groups. Normalised rates (/100,000) of bullying within these occupational groups illustrated a wide variation. Significant correlation (p<0.05) between the rates of change in occupation and the rate of bullying within these occupations was found. Gender specific relative risks of bullying were also calculated for each occupational group and showed large variations in the risk of bullying for men and women.

Characterization of Route Specific Impurities Found in Methamphetamine Synthesized by the Leuckart and Reductive Amination Methods

Impurity profiling of seized methamphetamine can provide very useful information in criminal investigations and, specifically, on drug trafficking routes, sources of supply, and relationships between seizures. Particularly important is the identification of “route specific” impurities or those which indicate the synthetic method used for manufacture in illicit laboratories. Previous researchers have suggested impurities which are characteristic of the Leuckart and reductive amination (Al/Hg) methods of preparation. However, to date and importantly, these two synthetic methods have not been compared in a single study utilizing methamphetamine hydrochloride synthesized in-house and, therefore, of known synthetic origin. Using the same starting material, 1-phenyl-2-propanone (P2P), 40 batches of methamphetamine hydrochloride were synthesized by the Leuckart and reductive amination methods (20 batches per method). Both basic and acidic impurities were extracted separately and analyzed by GC/MS. From this controlled study, two route specific impurities for the Leuckart method and one route specific impurity for the reductive amination method are reported. The intra- and inter-batch variation of these route specific impurities was assessed. Also, the variation of the “target impurities” recently recommended for methamphetamine profiling is discussed in relation to their variation within and between production batches synthesized using the Leuckart and reductive amination routes.

Emerging use of isotope ratio mass spectrometry as a tool for discrimination of 3,4-methylenedioxymethamphetamine by synthetic route

Drug profiling, or the ability to link batches of illicit drugs to a common source or synthetic route, has long been a goal of law enforcement agencies. Research in the past decade has explored drug profiling with isotope ratio mass spectrometry (IRMS). This type of research can be limited by the use of substances seized by police, of which the provenance is unknown. Fortunately, however, some studies in recent years have been carried out on drugs synthesized in-house and therefore of known history. In this study, 18 MDMA samples were synthesized in-house from aliquots of the same precursor by three common reductive amination routes and analyzed for 13C, 15N, and 2H isotope abundance using IRMS. For these three preparative methods, results indicate that 2H isotope abundance data is necessary for discrimination by synthetic route. Furthermore, hierarchical cluster analysis using 2H data on its own or combined with 13C and/or 15N provides a statistical means for accurate discrimination by synthetic route.

Rapid and semi-quantitative presumptive tests for opiate drugs

Digital image analysis was applied to the products of simple colour presumptive tests for opiates. Adobe Photoshop software was used for colour analysis to obtain analytical data in the form of a Red Green Blue (RGB) value. Calibration curves were developed for morphine, codeine, and diamorphine hydrochloride and the developed tests successfully applied to seized heroin samples to demonstrate the application of the technique in a forensic case context. Good agreement with gas chromatographic quantification results was obtained for the illicit samples analysed and a wide linear range and low detection limit for all drugs under test facilitated the application to illicit samples. The results show great potential for use as a semi-quantitative field test for illicit drug compounds.

The analytical and chemometric procedures used to profile illicit drug seizures

Over the last 20 years there has been an increasing interest in the development of robust systems, both analytical and statistical, to enable the linkage of seizures of illicit drug to each other. Much of this work has concentrated on the analysis of synthetic drugs, such as amphetamine and its analogues. In recent years, the analysis of both organic and elemental impurities as well as isotope ratios has advanced the usefulness of the techniques available. The application of specific chemometric methods to the derived analytical data has begun to provide the possibility of robust methods by which the resultant information can be interrogated.

Multivariate Statistical Methods for the Environmental Forensic Classification of Coal Tars from Former Manufactured Gas Plants

Compositional disparity within a set of 23 coal tar samples (obtained from 15 different former manufactured gas plants) was compared and related to differences between historical on-site manufacturing processes. Samples were prepared using accelerated solvent extraction prior to analysis by two-dimensional gas chromatography coupled to time-of-flight mass spectrometry. A suite of statistical techniques, including univariate analysis, hierarchical cluster analysis, two-dimensional cluster analysis, and principal component analysis (PCA), were investigated to determine the optimal method for source identification of coal tars. The results revealed that multivariate statistical analysis (namely, PCA of normalized, preprocessed data) has the greatest potential for environmental forensic source identification of coal tars, including the ability to predict the processes used to create unknown samples.

Digital image-based colourimetric tests for amphetamine and methylamphetamine

Digital image analysis was applied to the products of simple colorimetric [corrected] tests for amphetamine and methylamphetamine. Adobe Photoshop software was used for colour analysis to obtain analytical data in the form of a Red Green Blue (RGB) value. Calibration curves were developed for each compound and a number of illicit amphetamine samples were analyzed to demonstrate the application of the technique. A wide linear range and low detection limit for both drugs under test facilitated the application to illicit samples. Good agreement with gas chromatographic quantification results was obtained for the illicit samples analyzed by this method. The results show great potential for use as a semi-quantitative field test for illicit drug compounds.

Real time quantitative colourimetric test for methamphetamine detection using digital and mobile phone technology

The Simon presumptive color test was used in combination with the built-in digital camera on a mobile phone to detect methamphetamine. The real-time Red-Green-Blue (RGB) basic color data was obtained using an application installed on the mobile phone and the relationship profile between RGB intensity, including other calculated values, and the colourimetric product was investigated. A wide linear range (0.1-2.5mg mL(-1)) and a low detection limit (0.0110±0.0001-0.044±0.002mg mL(-1)) were achieved. The method also required a small sample size (20μL). The results obtained from the analysis of illicit methamphetamine tablets were comparable to values obtained from gas chromatograph-flame ionization detector (GC-FID) analysis. Method validation indicated good intra- and inter-day precision (2.27-4.49%RSD and 2.65-5.62%RSD, respectively). The results suggest that this is a powerful real-time mobile method with the potential to be applied in field tests.

Application of Unsupervised Chemometric Analysis and Self-organizing Feature Map (SOFM) for the Classification of Lighter Fuels

A variety of lighter fuel samples from different manufacturers (both unevaporated and evaporated) were analyzed using conventional gas chromatography-mass spectrometry (GC-MS) analysis. In total 51 characteristic peaks were selected as variables and subjected to data preprocessing prior to subsequent analysis using unsupervised chemometric analysis (PCA and HCA) and a SOFM artificial neural network. The results obtained revealed that SOFM acted as a powerful means of evaluating and linking degraded ignitable liquid sample data to their parent unevaporated liquids.