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Collin OL Niegel C Derhodes KE McCord BR Jackson GP 《Journal of forensic sciences》2006,51(4):815-818
The detection of a mixture of nine explosive compounds, including nitrate esters, nitroaromatics, and a nitramine in less than 140 sec is described. The new method employs a commercially available pulsed-discharge electron capture detector (PDECD) coupled with a microbore capillary gas chromatography (GC) column in a standard GC oven to achieve on-column detection limits between 5 and 72 fg for the nine explosives studied. The PDECD has the benefit that it uses a pulsed plasma to generate the standing electron current instead of a radioactive source. The fast separation time limits on-column degradation of the thermally labile compounds and decreases the peak widths, which results in larger peak intensities and a concomitant improvement in detection limits. The combination of short analysis time and low detection limits make this method a potential candidate for screening large numbers of samples that have been prepared using techniques such as liquid-liquid extraction or solid-phase microextraction. 相似文献
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Grattapaglia D Kalupniek S Guimarães CS Ribeiro MA Diener PS Soares CN 《Forensic science international》2005,149(1):99-107
A sample of 198 unrelated males distributed among the five geopolitical regions in Brazil were typed for the minimal Y-STR haplotype composed of microsatellite loci DYS19, DYS385I/II, DYS389I, DYS389II, DYS390, DYS391, DYS392 and DYS393. Gene frequency data, gene diversity, haplotype diversity and power of discrimination were estimated. An AMOVA indicated that 99.97% of the haplotypic variation is found within regions and only a small 0.03% and non significant variation is found among the five regions (Fst=0.00031, P-value=0.43). This result suggests that a single national database of Y-STR haplotypes can be used in the quantitative assessment of matches in forensic casework in the Brazilian population. A significant haplotype diversity of 99.8% was found and 172 different haplotypes were observed in 198 chromosomes. Haplotype (14-11, 14-13-29-24-11-13-13) with five occurrences in 198 chromosomes was the most frequent in Brazil. 相似文献
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