Determination of organochlorine pesticide and polychlorinated biphenyl residues in fatty fish by tandem solid-phase extraction cleanup

A rapid, multiresidue solid-phase extraction (SPE) technique for determination of organochlorine pesticide and polychlorinated biphenyl (PCB) residues in nonfatty fish was modified for use with fatty fish. In the modified procedures, samples are extracted with acetonitrile, and the extract is cleaned up with both C18 and Florisil SPE columns. Residues are determined by gas chromatography with electron capture detection. The original method was modified for use with fatty fish by reducing the amount of tissue extracted and by using an improved Florisil SPE cleanup. Recovery data are presented for 24 fortified organochlorine pesticide residues (0.12 ppm) and 3 fortified PCB residues (0.80 ppm) from flounder, bluefish, and shad samples, which contained 0.8, 5.4, and 22.6% fat, respectively. For the 3 types of fish, recoveries of 23 of 24 fortified organochlorine pesticide residues ranged from 55 to 129%, and recoveries of 3 fortified PCB residues ranged from 55 to 104%. There were no significant differences in recovery based on fish species and/or fat content for the majority of residues studied. This SPE method and the official AOAC method yielded comparable results for fish containing incurred organochlorine residues.     

Synthesis and degradation of hyaluronate by synovia from patients with rheumatoid arthritis

OBJECTIVE: Hyaluronate degradation was analyzed in cultures of healthy tissue and tissue obtained from patients with rheumatoid arthritis. METHODS: Arthritic and healthy synovial tissues were incubated in culture with [3H]glucosamine. Labelled hyaluronate was extracted and its size determined by gel filtration. The production of low molecular weight hyaluronate was analyzed by pulse-chase experiments. Radical production was measured by a cytochrome C reduction assay. RESULTS: Healthy tissues and some arthritic tissues that did not contain significant amounts of granulocytes produced high molecular weight hyaluronate. In contrast, arthritic tissue infiltrated with granulocytes released low molecular weight hyaluronate. Pulse-chase experiments suggested that hyaluronate was degraded in these arthritic tissues. Exogenous hyaluronate was degraded only by intact tissue, but not by cells in culture obtained from synovial membranes of synovial fluids. Hyaluronate degradation was accompanied by massive oxygen radical production. Radical scavengers protected hyaluronate from degradation in synovial tissue. Some protection was achieved by superoxide and catalase or by methionine and complete protection by the iron chelators diethyltriaminepentacetic acid or deferoxamine mesylate. CONCLUSION: Degradation of hyaluronate in arthritic synovial tissue may be inhibited in tissue culture by radical scavengers.     

Apparatus for the vertical orientation cone calorimeter testing of flexible polyurethane foams

Of concern to regulators and fire safety engineers is how flexible polyurethane foam drips and flows during burning. Specifically, flexible polyurethane foam forms a burning ‘pool’ of liquid as the foam decomposes, which can lead to accelerated flashover events. To fully study this phenomenon where the ‘pool fire’ accelerates heat release, large‐scale tests like the furniture calorimeter (American Society of Testing and Materials (ASTM) E1537) are used, and no small‐scale technique exists. In this paper, we present our work in developing a new sample holder that works with a bench‐scale heat release test, the cone calorimeter (ASTM E1354). The holder was built upon designs developed by the National Institute of Standards and Technology, which placed the foam in a cage in a vertical orientation during cone calorimeter testing. In this paper, we show the schematics for this test apparatus, as well as results obtained with this apparatus on four different flexible foams (shape memory and high‐density foam, flame retarded and non‐flame retarded). We compare the results from the vertical testing with that obtained via traditional horizontal ASTM E1354 testing. The advantages and disadvantages of this new apparatus are discussed in this paper. Copyright © 2014 John Wiley & Sons, Ltd.     

Day Labourers, Unemployment and Socio-economic Development in South Africa

One of the most visible forms of unemployment is the men who stand at the side of the road or on corners daily, waiting for any job that may come their way. It is estimated that there are nearly 1,000 places in South Africa where a minimum of about 45,000, mostly black African men, stand, waiting to be picked up. The South African space economy is characterised by an uneven distribution of economic activities. International empirical studies have shown that there is a geographical or spatial coincidence between levels of unemployment and levels of gross domestic product per capita. The first objective of this article is to highlight some of the basic demographic dynamics of day labourers. The second is to investigate the spatial distribution of and the relationship between day labourers, unemployment and the general level of socio-economic development in South Africa. Day labourers share a number of common characteristics, but there were also obvious differences in their morale and spirit. The analyses showed that there is also a general spatial coincidence between levels of socio-economic development and the numbers of day labourers in South Africa, with a relatively high correlation coefficient between the two.     

Konzentrationsabhängigkeit von Lösungswärmen und Lösungsentropien in metallischen Legierungen

Beschreibung der gemessenen Konzentrationsabhängigkeit isothermischer Gaslöslichkeiten durch Potenzreihen. Darstellung der Konzentrationsabhängigkeit des Wirkungskoeffizienten f³₂ sowie der Temperaturabhängigkeit des Wirkungsparameters ?³₂ im Mischlösungsmittel 1—3. Angabe von Gleichungen für die Wasserstofflöslichkeit in binären Nickel-Eisen-, Nickel-Kobalt-, Nickel-Kupfer- und Nickel-Chrom-Legierungen in Abhängigkeit von Druck, Temperatur und Konzentration. Verlauf von Lösungswärmen und Lösungsentropien von Wasserstoff in den angegebenen festen und flüssigen Legierungen.     

Leistungen von Pilgerstraßen,Stoßbänken und Rohrkontistraßen

Leistungen der Pilgerstraßen, Stoßbänke und Kontistraßen bei der Herstellung nahtloser Rohre. Ermittlung wesentlicher Einflußgrößen auf diese Leistungen.     

Diffusion von Silizium,Phosphor, Schwefel und Mangan in flüssigem Eisen

Zusammenhang zwischen Diffusion und Aktivität. Messung der Diffusionskoeffizienten von Silizium, Phosphor, Schwefel und Mangan in flüssigem Eisen sowie in kohlenstoffgesättigtem, flüssigem Eisen. Angabe der Konzentrationsabhängigkeit und der Temperaturabhängigkeit der ermittelten Diffusionskoeffizienten.     

Zeitschriftenreferate: Allgemeine Bestandteile der Lebensmittel

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