Showing papers by "German Criminal Police Office published in 1991"
TL;DR: In this article, a coupling of SFE and capillary SFC is used for the determination of polymer additives, and the coupling device described can also be used for “solventless” injection in SFC.
Abstract: Extraction with supercritical CO2 is a versatile method for sample clean-up and trace enrichment. The off-line coupling of SFE and HPLC is used to determine various explosives in debris as well as pesticides in soil. In food analysis the metod could be applied to determine cholesterol in noodles quantitatively. Correlations between the retention in RP chromatography and required extraction conditions could the established. The higher the organic modifier concentration in the eluent has to be, the smoother the extraction conditions required. With the non-volatile solutes studied, extraction temperature had no influence on extraction yield and speed. On-line coupling of SFE and capillary SFC is a very convenient and sensitive method for the determination of polymer additives. The coupling device described can also be used for “solventless” injection in capillary SFC.
53 citations
TL;DR: The results of the exercise demonstrate the correlation of typing that can be achieved within and between laboratories under conditions of minimal standardization.
52 citations
TL;DR: The analysis of explosive traces in different samples from criminal investigations is described in this paper, where the analytical procedure is preferably performed with gas chromatography and nitro/nitroso-specific detection.
Abstract: The analysis of explosive traces in different samples from criminal investigations is described. An important step for the analysis is sample preparation with solid-phase extraction. The analytical procedure is preferably performed with gas chromatography and nitro/nitroso-specific detection. The commercially available detection unit was modified. Possible solutions for the confirmation of the identity of an explosive trace are outlined.
24 citations
TL;DR: A procedure for the anion chromatography of low explosive residues is described in this article, where data are gathered from real samples after explosion experiments and the explosives investigated were different nitrate explosives and self-made mixtures of chlorate and sugar.
17 citations
TL;DR: In this paper, the topography of trace-bearing areas on the bullet and the cartridge case, as well as the chemical composition of gunshot residue particles, are determined by using the direct Zeeman atomic absorption spectroscopy (DZ-AAS).
Abstract: When a shot is fired, the projectile and the cartridge case are released from the weapon, as well as components of the priming charge and propellant, the so-called powder-gunshot residues. In order to solve firearm offences, it is therefore very important to determine the topography of trace-bearing areas on the bullet and the cartridge case, as well as the chemical composition of gunshot residue particles. Gunshot residue particles are made visible with the scanning electron microscope (SEM) and are analysed by means of energy-dispersive X-ray spectroscopy (EDXS) and lately also by means of wavelength-dispersive X-ray spectroscopy (WDXS). In addition to this, analyses of these particles are displayed by means of Auger electron spectroscopy (AES) and secondary ion mass spectroscopy (SIMS) and depth profiles are prepared. To determine the local distributions of gunshot residue elements with regard to their quantity, the direct Zeeman atomic absorption spectroscopy (DZ-AAS) is employed. Besides the determination of the chemical composition, the topography of the trace-bearing areas on the bullet and cartridge case plays an important part. For the detection of these surfaces, light optical and electron-optical methods are employed. Moreover, the use of opto-electronical testing systems has been attracting more and more attention recently.
5 citations
TL;DR: In this article, it is shown that a modern DSC instrument has sufficient sensitivity for direct measurement of the heat production in lower temperature ranges, which leads to more reliable hazard assessment.
1 citations
TL;DR: Das forensische Informationssystem Handschriften, Kurzbezeichnung FISH, wurde fur den Handscbriften-Erkennungsdienst des Bundeskriminalamtes entwickelt andererzu wurden Verfahren der MustererKennung and des Information Retrieval eingesetzt.
Abstract: Das forensische Informationssystem Handschriften, Kurzbezeichnung FISH, wurde fur den Handscbriften-Erkennungsdienst des Bundeskriminalamtes entwickelt. Ziel des Projektes war es, die Arbeitsablaufe im Handschriften-Erkennungsdienst zu vereinheitlichen und zu rationalisieren. Insbesondere sollte die Klassifizierung von Handschriften objektiviert und eine effektive Recherche ermoglicht werden. Hierzu wurden Verfahren der Mustererkennung und des Information Retrieval eingesetzt.