Funnel Method Research Articles

Evaluation of Modifications to Extraction Procedures Used in Analysis of Environmental Samples from Superfund Sites

Abstract Recoveries from an aqueous sample of the semi-volatile analytes listed on the EPA Target Compound List (TCL) are compared using 6 different methylene chloride extraction procedures. Four experimental designs incorporating a continuous extraction apparatus are evaluated, and 2 experimental designs using separatory funnel methods are tested. In addition, 2 concentration procedures are compared, and the loss of analytes associated with both extraction and concentration procedures are determined. These studies indicate that the most efficient and economical technique for the extraction of these compounds from an aqueous matrix is a single continuous extraction procedure performed at pH 2.

Compression of adsorbed monolayers at oil/water and air/water interfaces using a reversed funnel method

Etude de l'adsorption de dodecylsulfate de sodium et de Brij 58 a l'interface eau/hydrocarbure et eau/air

ツルグレン法による恙虫類の生息調査 : 3. 恙虫病の患家周辺部におけるフトゲツツガムシの発生

The presumption that Leptotrombidium pallidum, the most probable vector trombiculid of tsutsugamushi disease in Nagano Prefecture, would occur in the vicinity of patients' houses and would constitute a source of infection was determined by the following procedures. Housing lots including the rear and front gardens, the sides of pathways, grasslands, cultivated or abandoned fields and banks of these fields were selected in the neighbourhood of the houses of seven patients who contracted the diseases in 1986. From the selected spots with living signs of wild rodents, 10 or 15 soil samples, each with a volume of ca. 2,000(cm)^3,per one patient's housing area were taken and examined for the presence of chiggers by the Tullgren's funnel method. The samplings were carried out during the period from November 17 to December 3,1986. L. pallidum larvae were frequently found from the samples taken at the housing lots and paddy banks close to the patients' houses. No appreciable differences were observed between the environmental conditions of these patients' houses and non-patients' ones. The possibility that such penetrating distribution of vector trombiculid as observed in this study is common in other endemic foci was suggested as an alarm for the prevention of tsutsugamushi disease.

ツルグレン法による恙虫類の生息調査 : 2. 恙虫類の環境依存性と季節的発生消長

ツルグレン法による恙虫類の生息調査 : 2. 恙虫類の環境依存性と季節的発生消長

Effect of Certain Environmental Factors and Host Plants on Reproduction ofHoplolaimus galeatus

AHMAD, M., and T. A. CHEN. 1980. Effect of certain environmental factors and host plants on reproduction of Hoplolaimus galeatus. Plant Disease 64:479-480. The effects of soil texture and host plants on the reproduction of Hoplolaimus galeatus were investigated under greenhouse conditions. A three-way interaction among soil, crop, and pH existed. Sandy loam soil was more suitable for nematode reproduction than silty loam or loamy sand soil. The pH effect varied with the host plant; population increases were greatest at pH 7 for bean and pH 5 for barley. The rate of reproduction of H. galeatus was significantly higher on rye, barley, wheat, oats, soybean, corn, cabbage, and bean than on pepper, eggplant, lettuce, tobacco, and pea. The lance nematode Hoplolaimus galeatus has a wide geographic distribution and is reported to be associated with decline in plants (8). The host-parasite relationships of H. galeatus, however, have been established for only a few hosts. In view of the frequency of occurrence of H. galeatus on many crops in New Jersey and the limited information on its biology, studies were conducted on the influence of environmental factors and host plants on the reproductive potentials of this nematode. MATERIALS AND METHODS Nematodes were obtained from a stock culture of H. galeatus maintained in the greenhouse on bent grasses. The soil and roots from the stock culture were washed, and the nematodes were extracted from the soil suspensions with a modified Baerman funnel method (Cornell pie-pan method). The nematodes were counted in a 5-ml aliquot under X30 magnification. Nineteen plant varieties were tested for suitability as hosts for H. galeatus. Five replicates of each plant were grown in 12.5-cm clean pots filled with pasteurized sandy loam soil, pH 5.5. Four plants 5-7.5 cm high were inoculated with 200 adult nematodes; the fifth plant served as a control. Nematode inoculation was done by pouring the inoculum (200 nematodes/pot) into three holes about 1-2 in. deep next to the base of the plant. The pots were then watered lightly. Four months after inoculation, the nematodes were extracted and counted. Average numbers with four replicates per plant were used for statistical analysis. The root systems were examined for general

Multiresidue Analysis of Fourteen Organophosphorus Pesticides in Natural Waters

Abstract A method is described for the determination of 14 organophosphorus pesticides in natural waters at less than μg/L (ppb) concentrations. Two extraction methods are described: the vortex stirring method for water that forms light emulsions and the separatory funnel method for water that forms heavy emulsions during extraction. Extraction recoveries were 95– 110% for all compounds except crufornate (115%). Two concentration methods are also described with recoveries of 95–116%. Compounds were determined by isothermal gas chromatography using a flame photometric detector that is quantitatively sensitive to phosphorus. The sensitivity of the method for most of the 14 compounds was 0.01 ppb, using 1 L water. Retention times of all compounds were constant during isothermal analysis. Possible losses due to storage were also examined.

Comparison of the Tullgren Funnel and Soil Section Methods for Surveying Oribatid Populations

A comparison was made of a Tullgren funnel and a soil section method for estimating Oribatid population in a black pine woodland soil. The funnel method was found superior for extracting particularly small species while larger and woodfeeding species were more accurately estimated by the section method. For 8 out of 12 species investigated, the section method was more efficient in comparison to the funnel method. The relative efficiency of the two methods did not vary significantly according to season. Advantages, disadvantages, and scope of each method are discussed.

A STUDY OF THE SOIL FAUNA IN A MATURE STAND OF RED SPRUCE (PICEA RUBENS) IN THE UNIVERSITY OF NEW BRUNSWICK FOREST

AbstractThis investigation was concerned with fauna above and within the litter, fermentation, and humus layers of the soil in a mature stand of red spruce (Picea rubensSarg.). The following six microsites were designated for sampling: "open" and "closed" hollows, flats, and hummocks. "Open" and "closed" referred to the space among the tree crowns directly above the microsites. Three sampling techniques, namely core samplers, pitfalls and Tullgren funnels, were employed. Samples were collected weekly from spring to winter in 1966 and 1967 by all methods except that in 1966 Tullgren funnel samples were collectell biweekly. Collected fauna comprised five Phyla, 11 classes, 28 orders, and approximately 124 families. The transformed core sample and Tullgren funnel data were analyzed using an ANOVA (2-way classification) procedure. Transformed pitfall data required an ANOVA (2-way classification, with sampling) procedure. The core sample and Tullgren funnel methods indicated a significant difference (α = 0.10) among microsites based on total weekly (or biweekly) faunal catches in all but one case (which approached significance). In 1966 there were no significant differences (α = 0.10) among the pitfall microsites but in 1967 there were. In all cases there were significant differences (α = 0.10) in the total weekly or biweekly catches of fauna from the various microsites.

Recherches écologiques dans la savane de Lamto (Côte-d’Ivoire) : Etude quantitative préliminaire des micro-arthropodes du sol

A preliminary, quantitative study of soil micro-arthropod populations was made during a four-month period in burnt and unburnt savanna areas at Lamto in the Ivory Coast. Soil samples were taken to a depth of 80 cm using a core borer, and extraction undertaken using a dry funnel method. Densities were low in soil, higher under grass clumps. Average densities of Acarina, numerically the dominant micro-arthropod group (comprising 74 % of total), were 34,000/m² and 20,000/m² in burnt and unburnt areas respectively. Acarina were more abundant in the 0-5 cm and 40-60 cm soil horizons than in intermediate horizons. Within the Acarina, Actinedida were numerically the most important group, while Oribatida were poorly represented. After the Acarina, Collembola were the most important soil micro-arthropod group, followed by Myriapoda and Diplura.

Estimation of Rumen Microbial Nitrogen by Three Analytical Methods

Perchloric acid-soluble residue, tungstic acid precipitate, and separatory funnel techniques were evaluated by comparing results of microbial cell dry matter, per cent nitrogen, and total nitrogen in rumen samples before and after feeding. Significantly less (P 0.01) cellular dry matter remained in perchloric acid samples than with other methods due to procedural complications in washing and decanting specimens. As a result of incomplete separation by the separatory funnel techniques, per cent nitrogen in the dried microorganisms was significantly reduced (P 0.01); however, microbial preparations by the separatory funnel method contained less (P 0.10) feed contamination than nonseparatory funnel procedures. The tungstic acid method consistently yielded significantly greater (P 0.01) amounts of total nitrogen from the rumen microbial samples, suggesting that limitations in the other methods were of importance in quantitative analyses.

Centrifuge separation of heavy minerals-a new apparatus

ABSTRACT A new instrument to aid the separation of heavy minerals is described. The apparatus delivers a larger crop than with the conventional funnel method for fine-grained fractions, and the standard error is also smaller. The instrument and method is described in detail and a short summary of the results obtained is given. It is suggested that the instrument be applied for describing the heavy-mineral content of sand samples quantitatively. The experimental error introduced during the filtering off, drying and weighing of samples was also tested, and appears to be the main source of the experimental error. The optimum sample size for the instrument was determined.

The Determination of Numbers of Leatherjackets in Sample Turves

Accurate determination of the numbers of leatherjackets (larvae of the Tipula oleracea group) in sample turves is necessary for economic as well as ecological purposes. Third and fourth instars and pupae can be fully recovered by examination of residues after the turf has been broken up, teazed out and washed carefully under a jet of water on a bank of sieves. For full recovery of first and second instars the washing must be followed by an adaptation of the flotation-separation technique (Salt & Hollick 1944). These 'mechanical' methods are, however, very laborious and time-consuming. Attention naturally turns, therefore, to the feasibility of making leatherjackets quit the turf of their own accord by 'repellant' methods (cf. MacFadyen 1955). For larvae after the second instar, entomologists of the National Agricultural Advisory Service (N.A.A.S.) are actually using a repellant method, the 'St Ives Method' (Cohen 1953). Essentially this consists in bringing leatherjackets to the surface by pouring a solution of an irritant, St Ives fluid, on the turf in the field. The sampling unit is 1 sq. ft on which 1 pt of solution is sprinkled evenly. Practically nothing is known of the efficiency of this method. The efficiency could, of course, be established simply by washing the square-foot turves immediately after the St Ives treatment. Washing square-foot turves is, however, a formidable task, and a great deal of labour might be expended only to find that the St Ives method was after all unreliable for ecological purposes. We decided, therefore, to explore first the possibilities of an idea for another repellant method. In 1939, one of us (A. M.) had tried to drive ticks, Ixodes ricinus L., out at the bottom of a layer of grass mat by heat advancing from an electric light bulb fixed just above the mat surface (the Tullgren funnel method). The results were not satisfactory. Rightly or wrongly he interpreted this as being a consequence of using a dry heat; the discomfort signalling retreat might be accompanied by decreasing capacity for locomotion because the tick loses water readily. The idea of trying a wet heat thereupon occurred to him. Ticks would not be desiccated and might well be driven up out of the mat by raising hot water slowly through it. As it happened, the idea was not tested then because the particular tick problem involved was solved in another way. But with the prospect of washing numerous square-foot turves, the idea seemed well worth trying on leatherj ackets in 1954. Leatherjackets live in tunnels which open on the soil surface. Preliminary trials

Aaltjesziekte in aardbeien I

I. During the winter 1946–1947 strawberry plants in the Netherlands suffered much from the severe cold. The surviving plants show leaf deformations strongly resembling those caused by eelworm-disease. The symptoms of both are described. II. In the variety Madame Moutot June yellows (better called Springyellows) often causes leaf deformations (in consequence of the slower growth of the mottled parts of the leaves). These irregularities resemble the symptoms of eelworm-desase. A list of the differences is given. III. Doubtful cases of eelworm-disease cause much trouble in strawberry certification. At the Laboratory of Mycology and Potato Research at Wageningen these cases are being studied by the improved funnel method of IrSeinhorst (who will publish it before long). The results of the first year of this investigation, 1946, are discussed. Not only did the strawberry eelworm (Aphelenchoides fragariae (Ritz. B.) occur in the diseased plants, but also the stem and leaf eelworm Ditylenchus dipsaci (Kuehn).

Tyroglyphid mites in stored products Methods for the study of population density

The known methods for detecting the presence of tyroglyphids are described. For coarse materials, such as seeds, sieving is recommended. For flour, it is better to examine exposed surfaces, or to keep samples in glass vessels and examine for the runnels made by mites against the glass. Methods of sampling to provide information about the density and extent of infestations are described. Samples must usually be treated in the laboratory. While methods which do not involve the separation of the mites from the material are referred to, such separation is usually necessary. Mites may be separated from most materials by the modified Berlese funnel method of Chernuishev and Petrova; means of overcoming certain disadvantages are suggested. However, vigorous sieving is recommended for coarse materials, and a flotation method, using dichlorethylene, for fine materials such as flour. It is usually more satisfactory to examine and count the mites than to estimate the numbers volumetrically or gravimetrically. They are counted in a dish containing oil, placed on squared paper under a low‐power microscope. A modification of this method, for dealing with large numbers, is described. Methods of expressing population density are briefly discussed.

A PORTABLE GASTRIC LAVAGE OUTFIT.

With the modern tendency to simplify therapeutic and diagnostic measures it seems strange indeed that the old method of gastric lavage should be so persistently employed; and this, in spite of the fact that the Leube-Rosenthal method has been so long known to the profession. Surely no one who has employed both methods can consistently maintain that the funnel method is either simpler, cleaner or more efficacious. In fact, no method may be considered simple which requires the amount of physical exertion necessary in the process of raising and lowering the funnel; no method clean which permits of the possibility of soiling the patient and things about him, and surely no method can be more efficacious than one which permits of the regulation of the in-flow and the out-flow of water, as does the Leube-Rosenthal method. Yet Herschell, though he considers the apparatus very admirable in the hands of a