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Analysis of accelerants in fire debris involves the isolation of residual volatiles from the matrix and the analysis of these volatiles, usually by gas chromatography (GC). The resulting chromatograms are interpreted by comparing to a library of accelerant chromatograms obtained under similar conditions. This review first mentions ASTM's system in classifying fire accelerants into light petroleum distillates, gasoline, medium petroleum distillates, kerosene, heavy petroleum distillates, and unclassified compounds. Chromatograms with well-resolved n-alkane homolog patterns are most recognizable. Chromatograms that are inadequately resolved can be improved by columns having higher efficiency or selectivity, while those with too much interference can be improved by physical removal or reduction of these interfering compounds or selective detection. Using a mass spectrometer (MS) as the detector in GC/MS applications allows the display of common ions shared by compounds with similar structural features, thus greatly facilitating pattern recognition practices. Computer algorithms are now available for automated recognition of patterns possessed by various categories of accelerants. The state-of-the-art in forensic laboratories' analysis of accelerants in fire debris is presented as an appendix to this review. Data generated in annual proficiency tests over an 8-year period (1987-1995) revealed increased use of GC/MS instrumentation and some persisting problems, which include false positives and difficulties associated with component discrimination in the sample preparation process and recognition of partially evaporated distillates.

The isolation of ignitable liquid components, usually petroleum-based distillates from fire debris, is an important step in deciding whether a fire is of natural or incendiary origin. Steady progress has been made to develop sample preparation methods capable of enriching target analytes in high yield and within a short period of time. Heated headspace enrichment methods are currently most widely used. There are several variations of this basic technique. Carbon-based adsorbents are most popular. They come in different forms and shapes, including a flat sheet of polymer, impregnated with carbon particles. The analyst cuts a small strip from this sheet and suspends it in the heated headspace above the debris sample. The volatiles adsorb onto the carbon surface, eventually reaching an equilibrium condition. The process is usually carried out in an oven. This convenient method, called the static method, has largely replaced the dynamic method, which uses a granular charcoal adsorbent. In the latter, the heated headspace is drawn over a short trap packed with charcoal, using a source of vacuum such as a pump or pushed along using pressurized nitrogen. The headspace volatiles in both the static and dynamic method are recovered by elution with a solvent, usually carbon disulfide. Recently, a promising variation of the static headspace method has been introduced. It is based on the use of a tiny amount of a polysiloxane polymer which has been coated onto the tip of a thin silica fiber. The fiber can be retracted into a syringe-type needle and the adsorbed headspace vapor can be conveniently introduced into the heated injector port of a gas chromatograph. No solvent is required. This technique, abbreviated SPME (for solid-phase microextraction) has many attractive advantages but it is not without some problems. Low boiling range accelerants, including water-soluble polar substances such as ethanol, are poorly retained on methylsiloxane type polymers. The recent introduction of hybrid fibers containing a combination of carbon and a methylpolysiloxane polymer has extended the usefulness of SPME toward the high volatility end. With judicious optimization of experimental conditions, it is now possible to obtain an adequately representative sample of the headspace above the fire debris sample. It is thus possible to characterize the full spectrum of potential liquid accelerants, ranging from alcohols and similar water-soluble substances to high boiling range fuel oils.

Information on the chemical analysis of water soluble accelerants such as ethanol and acetone is sparse. It appears that only a few laboratories routinely assess fire debris samples for such ignitable liquids. We have evaluated the currently available analytical methodology for these types of compounds. Direct heated headspace, passive headspace enrichment by Diffusive Flammable Liquid Extraction (DFLEX®) and adsorption onto a Carboxen® based Solid Phase Micro Extraction (SPME) fiber are suitable methods. A newly developed micro-distillation procedure used in conjunction with SPME methodology appears to be particularly simple and promising.

An analysis system is presented that is specifically geared toward the detection of petroleum based volatiles in suspect arson samples. Advantage is taken of the high selectivity of mass spectrometry toward aliphatic and aromatic hydrocarbons. Data acquired by gas chromatography-mass spectrometry are subjected to automated post run data treatment. The system attempts to categorize chromatographic profiles by establishing the presence of key components. Comparison is made to data from standards stored in the memory of the computer. Retention time information as well as mass spectral criteria are used. Based on the detection of diagnostic components and determination of their relative intensities, samples are categorized as falling into one of five categories of petroleum based accelerates. Extensive use is made of Macro programming. The rationale of the search is discussed and details of the program structure are provided. A typical example is presented

A previously unknown haemagglutinin, named Sambucus nigra agglutinin-III (SNA-III), has been purified from the fruit of the elder (Sambucus nigra). Whereas elder bark agglutinin I (SNA-I) is highly specific for terminal alpha 2,6-linked sialic acid residues, SNA-III displays a high affinity for oligosaccharides containing exposed N-acetylgalactosamine and galactose residues. Different N-terminal sequences and the amino acid composition distinguish the fruit lectin from elder bark agglutinin II (SNA-II), which shows a similar carbohydrate specificity. The 40-fold higher affinity of SNA-III for asialofetuin than for human asialo-alpha 1-acid glycoprotein and human asialotransferrin respectively suggests a preference for O-linked glycans. SNA-III occurs mainly as a monomeric glycoprotein, but tends to form di- and oligo-meric aggregates. This aggregation seems to mediate the multivalent interaction, leading to agglutination. SDS/PAGE revealed two major polypeptides with apparent molecular masses of 32 and 33 kDa respectively. This heterogeneity is probably a result of proteolysis in the C-terminal region. Binding to concanavalin A and susceptibility to peptide: N-glycosidase F indicated the presence of N-glycosidically linked oligosaccharides.

Abroad review of current methods for the recovery of liquid residual accelerants in fire debris is given. A summary of current practices of sample preparation methods in U.S. laboratories is presented. Sampling of heated headspace is useful as a screening method. It is also applicable for samples that contain a high concentration of accelerant. Distillation-based methods are effective only when large amounts of accelerants are present but they permit the physical isolation of relatively pure liquids, including some water-soluble materials such as alcohols. Solvent extraction is particularly advantageous for accelerants of low volatility such as diesel fuel or highly evaporated petroleum-based products, but it is very susceptible to interferences from the matrix. Dynamic enrichment by adsorption/elution is the most popular and widely used recovery method for liquid accelerants. It offers high enrichment factors but shows weaknesses with respect to polar and low-volatility liquids. No single method is universally effective for all types of accelerants that are commonly encountered in practice. It appears that currently applied recovery methods are particularly weak for water-soluble organics such as alcohols. Sample preparation methods have to be viewed in conjunction with the method to be used to characterize and identify suspect accelerants. Gas chromatography is used almost exclusively for separation and measurement. Selective detection of components that are diagnostic of accelerants allows important trade-offs between sensitivity, chromatographic efficiency and the level of interferences that can be tolerated. Pattern recognition with comparison of chromatographic profiles is greatly simplified if interferences from the matrix can be suppressed. Application of capillary columns capable of high resolution facilitates the recognition of diagnostically important components. Petroleum-based fluids and products are ubiquitous in the human environment and it is therefore particularly important to pay attention to petroleum-based fluids that are derived from such sources. Many common inconspicuous household materials contain petroleum-based solvents and are thus a part of the natural background. The term sensitivity as it relates to the effectiveness of a recovery method must be critically viewed in this light.

Der Aufbau des Kapitels „Rechtsgrundlagen“ orientiert sich an der Frage: „Was soll mit dem Baggergut passieren?“ und stellt die bei der jeweiligen Ablagerungsart relevanten Rechtsgrundlagen dar. Diese Darstellung beschrankt sich in erster Linie auf die erforderlichen Genehmigungen. Welche weiteren rechtlichen Regelungen im Zusammenhang mit der jeweiligen Genehmigung zu beachten sind, ist eine Frage des Einzelfalls. Eine vom Einzelfall losgeloste, abstrakte Darstellung aller weiteren in Betracht kommenden Rechtsgrundlagen ist im Rahmen dieser Arbeit nicht leistbar, zumal es sich im wesentlichen um landesrechtlich geregelte Genehmigungsverfahren handelt. Insofern konnen lediglich einige grundlegende, ubergreifend anwendbare weitere Rechtsgrundlagen dargestellt werden.

Application of Tagetes minuta floral extract to silica gel column chromatography produced 2 fractions with the hydrogenate part 20-30 times more toxic to larvae and 12-13 times more toxic to adults of Aedes aegypti and Anopheles stephensi, respectively, than the oxygenate part. Further fractionation by column chromatography of the hydrogenate fraction produced 4 thiophenes, 5-(but-3-ene-1-ynyl)-2,2'-bithiophene, 5-(but-3-ene-1-ynyl)-5'-methyl-2,2'-bithiophene, 2,2',5',2"-terthiophene, and 5-methyl-2,2',5',2"-terthiophene. These compounds in Tagetes minuta are largely responsible for the toxicity exhibited against the tested mosquitoes.

Hochdruckapparate werden mit verschiedenen Verschlussen ausgerustet. Treten Undichtigkeiten auf, so mussen sich die Masnahmen zum Abdichten nach der Verschlusart richten. An einem Beispiel aus der Praxis — Doppelkonusdichtung mit Titan-Folie — werden der Ablauf einer Storung und deren Beseitigung beschrieben. Auserdem werden Gleichungen fur die Schraubenkraft am selbstdichtenden Doppelkonusring und die Drucke an den Dichtflachen in Abhangigkeit vom Innendruck abgeleitet. Eine hinreichend exakte Berechnung der wirksamen Krafte fur die Doppelkonusdichtung ist damit moglich.

Die Anthocyansynthese des Senfkeimlings (Sinapis alba L.) wird uber das Phytochrom und eine hypothetische “Hochenergiereaktion” (=HER) reguliert (Mohr 1957). Das Wirkungsspektrum der HER zeigt Gipfel im Dunkelrot und im Blau.

Es wurden in dieser Arbeit die lichtabhangige Anthocyansynthese und die Photosynthesekapazitat bei Senfkeimlingen (Sinapis alba L.) verglichen. Die dargestellten Daten zeigen, das kein Anlas besteht, die lichtabhangige Anthocyansynthese von Keimpflanzen mit einer Funktion des Photosyntheseapparates in Beziehung zu bringen, wie es neuerdings (Downs 1964, Downs u. Mitarb. 1965) fur moglich gehalten wurde. Vielmehr mus die lichtabhangige Anthocyansynthese als eine typische Manifestation der vom Phytochrom abhangigen Photomorphogenese angesehen werden. Nach unserer Auffassung bewirkt das Phytochrom 730 eine differentielle Genaktivierung (Hock und Mohr 1964).

Crystalline rocks from breccias of the Ries basin, Germany, contain highly deformed quartz. Various planar deformation structures could be observed and classified into five different types: (1) Decorated planar elements, (2) Non-decorated planar elements, (3) Homogeneous lamellae, (4) Filled lamellae, (5) Planar fractures. All these structures are parallel to crystallographic planes: {10¯13}, {10¯12}, {10¯11}, {0001},{11¯21}, {11¯22}, {21¯31}, {51¯61}, {10¯10}. The most typical and most abundant planar structures are decorated and nondecorated planar elements parallel to {10¯13} and {10¯12}. Planar fractures are parallel to {0001} and {10¯11} and form at lower stress levels, probably earlier than the planar elements. Quartz containing planar elements, especially of the non-decorated type, has lower density, index of refraction and birefringence than normal quartz. This “quartz” is apparently a mixture of an amorphous phase and crystalline quartz, the amount of which can be calculated using average density or refractive index. Comparison of planar quartz structures found in tectonites and those produced artificially under static or dynamic high pressure conditions demonstrates that Ries quartz closely resembles deformed quartz recovered from shock wave experiments. The planar structures found in Ries quartz have been formed by shock wave actions with peak pressures in the 100–400 kbar range. Planar elements are explained to be traces of gliding processes during shock loading visible due to the fact that a high pressure phase (stishovite and/or a stishovite-like glass phase) has been produced along the glide planes. Upon pressure release most of the high pressure phase was transformed into an SiO2-glass (diaplectic glass). In comparison with experimental data the amount of residual crystalline quartz as well as type and orientation of planar structures in the quartz grains are clues to estimate the peak pressures responsible for these deformations. Shock waves with peak pressures exceeding about 400 kbar completely transform quartz into diaplectic SiO2-glass.

— How does a plant convert electronic excitation of chlorophyll into stable chemical potential? The time scales of fluorescence (10--9 sec) and steady-state enzymatic turnover (10–2 sec) indicate that energy storage must be involved. Millisecond delayed singlet emission from chlorophyll allows measurement of metastable energy storage at Photoreaction II. Activation of noncyclic electron transport results in more rapid decay and in increase of emission at 10--3 sec, both effects being inhibited by the poison DCMU. These results can be explained by at least three different models of the reaction center: the oxidized chlorophyll model, the chlorophyll triplet model, and the two-quantum electron-hole model.

Xenopus embryos injected with tritiated thymidine throughout the stages of embryonic retinal neurogenesis showed that more than 95% of the embryonic retinal cells are born within a 25 hr period. While there are shallow central to peripheral, dorsal to ventral, and interlaminar gradients of neurogenesis in these eyes, throughout most of this 25 hr period, postmitotic cells are being added to all sectors and layers. Small clones of differentiated retinal neurons and glia derived from single neuroepithelial cells injected with HRP. These clones were elongated radially. They were also composed of many different combinations of cell types, suggesting a mechanism whereby determination is arbitrarily and independently assigned to postmitotic cells. Such a model, when tested statistically, fits our data very well. We present a scheme for cellular determination in the Xenopus retina in which a coherent group of clonally related cells stretch out radially as lamination begins. This brings different cells into different microenvironments. Local interactions in these microenvironments then lead the cells toward specific fates.

An investigation involving sampling the rapidly changing environment of the Shuttle cargo bay is considered. Four time-integrated samples and one rapid acquisition sample were collected to determine the types and quantities of contaminants present during ascent and descent of the Shuttle. The sampling times for the various bottles were controlled by valves operated by the Data Acquisition and Control System (DACS) of the IECM. Many of the observed species were found to be common solvents used in cleaning surfaces. When the actual volume sampled is taken into account, the relative mass of organics sampled during descent is about 20 percent less than during ascent.

Stoichiometric amounts of chloroplast thylakoids photophosphorylate free AMP to tightly bound ADP. Free ADP is a poor competitor for this AMP photoreaction, which saturates below 16 μM AMP. The inhibitor, diadenosine pentaphosphate, abolishes AMP photophosphorylation, and inhibits dark ADP binding. Taken together, these data imply that this photoreaction involves the high affinity nucleotide binding site(s) of chloroplast coupling factor CF1, and that little mixing with free nucleotides occurs.

A method is described in which gas chromatographic (GC) data obtained from cuticular hydrocarbons are treated by methods of pattern recognition. Based on a recently described sample preparation procedure, GC data are normalized to eliminate slight variations in chromatographic conditions and converted into the proper format for discriminant analysis by computer. The results of several methods of data treatment and display are discussed, based upon the chemometric system package, ARTHUR. The approach has the advantage of largely removing operator bias.

The volatile organic components in the spacecraft cabin atmosphere of Skylab 4 were trapped on a solid adsorbent at various times during the mission. In post-flight analyses, more than 300 compounds in concentrations from less than 1 ppb up to 8000 ppb could be detected by high-resolution gas chromatography. In the samples of the 11th, 47th, and 77th day of the mission, approximately 100 components in the molecular weight range of 58 to 592 were identified by mass spectrometry. Besides components known from other environments, such as alkanes, alkenes, and alkylated aromatic hydrocarbons, components typical for the human metabolism such as ketones and alcohols were found. Other typical components in the spacecraft atmosphere are fluorocarbons (freons) and various silicone compounds, mostly normal and cyclic methylsiloxanes.

Gas chromatography (GC) data obtained from the cuticular hydrocarbons of the black imported fire ants are treated by methods of pattern recognition. Based on a recently described sample preparation procedure, GC data are normalized to eliminate slight variations in chromatographic conditions, and converted to the proper format for discriminant analysis by computer. The results of several methods of data treatment and display are discussed, based on the chemometrics system package, ARTHUR.

There is general agreement that photoreaction II (the oxygen-evolving photoreaction as defined by DUYSENS et al. (1961) is responsible for nearly all delayed light emission from the photosynthetic apparatus of the oxygen-evolving plants (BERTSCH et al 1967, GOODHEER 1963). RUBY & BROWN (1970) however, utilizing Bishop’s Scenedesmus mutants and a French press method for separating the two photoreactions, have suggested that photoreaction I might contribute to the millisecond delayed emission. It is therefore pertinent to utilize a different method for separating the two photoreactions, and to examine the resulting fractions for delayed light emission. We have prepared subchloroplast fractions according to the method of ANDERSON & BOARDMAN (1966) with the non-ionic detergent digitonin. These detergent-solubi1ized lamellar fractions are enriched in either photoreaction I (D-144) or in photoreaction II (D-10). We report delayed light measurements in the msec time range, as well as photochemical studies, on the two fractions as compared to chloroplasts.

The delayed light which ARNOLD and STREHLER found in 1951 to be emitted from all photosynthetic systems is now being recognized as a reliable measure of photosynthetic energy storage between loss of excitation from the chlorophyll singlet (10–9 sec) (BRODY & RABINOWITCH 1957, DIMITRIEVSKY et al. 1957, BUTLER & NORRIS 1963) and production of chemical free energy in the electron transport chain (10–2 sec in the steady-state) (EMERSON & ARNOLD 1932). This delayed singlet emission from chlorophyll is clearly due to low probability re-excitation of chlorophyll by back reactions of photosynthetic energy conversion at photoreaction II (BERTSCH et al. 1967) (as defined by DUYSENS et al. 1961). However, the delayed light may also be affected by “high energy states” or “high energy intermediates” of photosynthetic phosphorylation.

A high resolution open tubular column, 180 m×0.25 mm ID, using Emulphor 0 as the stationary phase was found necessary to resolve all six isomers of dimethyldiphenylmethane. For complete separation, two isothermal runs are required since one of the isomeric pairs loses resolution by a decrease in temperature.