Straw residues

Mohn-saft, OT. poppy juice, opium, -samen, ot. poppyseed, -saure,/. meconic acid, -stoff, m. narcotine, -stroh, n. lit., poppy straw (residue from extraction of poppy heads and stems). 

Plant residues can provide substrates for the production of phytotoxic metabolites by soil microorganisms but they can also support the growth of pathogens and other deleterious micro-organisms. This is illustrated by reference to the problems of establishing crops drilled in the presence of straw residues and of decaying weed and grass residues that have been previously killed with herbicides. 

In the direct drilling (no-till seeding) practice in the united Kingdom/ straw residues from the preceding crop are usually burnt because poor crop establishment and yields can result/ particularly on heavy soils in wet years (10). Similar problems can occur in the conservation tillage systems oF the Pacific Northwest (L.F. Elliott and H.-H. Cheng/ this volume). 

The rice straw residue is seen to have limited intrinsic value indeed its presence is a barrier to the subsequent year s wheat crop. In southern parts of India it is sometimes collected for animal fodder, but it is poor food, being high in Silica content. If the farm is within 10 km of a green energy power plant, the straw could be collected for energy production similarly proximity to a paper manufacturer affords a market for the straw. However, most of the straw has no market, and approximately 12 million toimes is burnt aimually in Punjab alone (Sood 2013). 

In a 1-litre three-necked flask, fitted with a mechanical stirrer, reflux condenser and a thermometer, place 200 g. of iodoform and half of a sodium arsenite solution, prepared from 54-5 g. of A.R. arsenious oxide, 107 g. of A.R. sodium hydroxide and 520 ml. of water. Start the stirrer and heat the flask until the thermometer reads 60-65° maintain the mixture at this temperature during the whole reaction (1). Run in the remainder of the sodium arsenite solution during the course of 15 minutes, and keep the reaction mixture at 60-65° for 1 hour in order to complete the reaction. AUow to cool to about 40-45° (2) and filter with suction from the small amount of solid impurities. Separate the lower layer from the filtrate, dry it with anhydrous calcium chloride, and distil the crude methylene iodide (131 g. this crude product is satisfactory for most purposes) under diminished pressure. Practically all passes over as a light straw-coloured (sometimes brown) liquid at 80°/25 mm. it melts at 6°. Some of the colour may be removed by shaking with silver powder. The small dark residue in the flask solidifies on cooling. 

Insulation Boa.rd. The panel products known as insulation board were the earliest commodity products made from fibers or particles in the composite panel area. These are fiber-base products with a density less than 500 kg/m. Early U.S. patents were obtained in 1915 and production began soon thereafter. The initial production used wood fiber as a raw material, but later products were made of recycled paper, bagasse (sugar cane residue), and straw. Schematics of the two major processes still ia use are shown ia Figure 4. 

A major source of particulate matter, carbon monoxide, and hydrocarbons is open burning of agricultural residue. Over 2.5 million metric tons of particulate matter per year are added to the atmosphere over the United States from burning rice, grass straw and stubble, wheat straw and stubble. 

To date, the structural features of pectic polysaccharides and plant cell walls have been studied extensively using chemical analysis and enzymatic degradation. In addition, research on isolation and physicochemical characterisation of pectin from citrus peels, apple peels, sunflower head residues and sugar beet pulp has been reported (2). However, the pectic polysaccharides extracted from wheat straw have only previously been reported by Przeszlakowska (3). The author extracted 0.44% pectic substances from Author to whom correspondence should be addressed. 

Plant material water contents range from high (>90%, e.g. vegetables) to low (< 10%, e.g. straw, herbs, tea, hops, etc.). Thus the ratio between the analytes (residues) and the organic matter potentially interfering with the analysis is very different for, e.g., cucumber and camomile tea. Other ingredients in plant materials such as acids, oil, sugars, starch or substances typically for the taste and effect of plant materials may have properties similar to those of the analytes and thus interfere in or influence the cleanup procedures. 

To the flasks for the crop and soil samples (Section 6.1), add 2mL of 0.01 M Tris-HCl buffer solution (pH 7.7) and 50 and 100 qL of 1M Tris-HCl buffer solution for wheat grain, bariey grain and rice straw, and for soil, respectively. Adjust the pH to about 7.7 (confirm the pH with a pH test paper using the sample of untreated area). Homogenize the residue with ultrasonication and transfer the homogenate to the top of an ion-exchange column. Wash the flask twice with 2mL of 0.01 M Tris-HCl buffer solution and transfer the washings to the column. Elute the column with 40 mL of the same buffer solution. Discard this eluate. 

Pyriminobac-methyl in plant samples (rice grains and rice straw) and soil is recovered by refluxing with aqueous acetone. After removing acetone from the extract, pyriminobac-methyl in the aqueous solution is transferred into n-hexane. The n-hexane layer is dried and evaporated under reduced pressure. The residue from soil... 

Connect a Sep-Pak Plus NH2 column with a Sep-Pak Plus Silica column (place the silica column on the elution side). Condition the connected column with 5 mL of n-hexane. Dissolve the residue of rice grains and rice straw (Section 6.3.2) in a small volume of n-hexane and transfer the solution to the column. Elute with 6mL of n-hexane-ethyl acetate (9 1, v/v) and discard the eluate. Remove the NH2 column. Elute the Sep-Pak Plus Silica column with 15 mL of n-hexane-ethyl acetate (4 1, v/v) and collect the eluate in a 50-mL pear-shaped flask. 

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