Electrochemical modifications of proteins. 1. Glycitolation.

When an electrochemical method is tentatively applied for N-alkylation of proteins, some Maillard reactions occur on the counter electrode. A low level of reductive N-alkylation of casein was obtained on a cathodic electrode, but the method unfortunately remains poorly efficacious in comparison with those using a hydride donor such as sodium cyanoborohydride. Electroassisted reductive N-alkylation is suitable only for basic proteins such as histones or lysozyme. For other proteins, an alternative consists of either methylating carboxylic residues to increase the value of their isoelectric pH or coating them with a cationic detergent.     

Prof. Dr. Dr. h.c. Heinz Peschke zum 65. Geburtstag

The materials of article had been reported at the International Symposium "Nutritional and environmental Research in the 21st Century - The value of long-term field experiments", 5-7 June 2002, Bad Lauchstädt and Halle upon Saale. Agrochemical monitoring of the basic landscape components was launched in order to assess human impacts of land-use on the site of Barybino Experimental Station (Moscow Region, clay loam soddy-podzolic soils. 55°30'N, 37° 36' E). The climate is moderate continental, mean annual temperature of 3.8 °C and mean precipitation of 567 mm (1965-1998) at an elevation of 185 m above sea level. A typical soil cover pattern is represented as a complex of soddy-podzolic soils (podzo-luvisols) with excessive surface moistening features manifested differently according to the influence of the micro relief. The study was carried out from 1991 to 2001 in a crop rotation of silo maize, barley, perennial grasses (clover with timothy) and winter wheat, under different systems of fertilization (application of organic as well as mineral fertilizers, plant remedies and their combinations). Agrochemical monitoring let to establish the anthropogenic impacts on the system "soil-nutrients-plant"-environment. Alterations of the landscape components affected by human activities and climate change were estimated. At the site it could be shown that the amount of precipitation, soil properties and type of cultivated crop had mainly influenced migration of the nutrient elements.     

Chemical Principles of Environmental Pollution,B.J. Alloway and D.C. Ayres

Water, Air, &; Soil Pollution -     

美国研究人员用大肠杆菌生产生物燃料

植物油和动物油是制造很多生物燃料、表面活性剂、溶剂和润滑剂的原材料。对这些油料的不断增长的需求以及它们有限的供应正在导致粮食竞争、价格上涨和与它们的生产相关的环境问题。通过发酵从丰富的、高性价比的可再生资源来直接生产这些产品是一种具有可持续性的替代办法。传统生物能源技术多利用玉米或甘蔗来生产乙醇,然后制成燃料,但这可能导致生物能源作物与粮食作物争地。因此,近年来科研人员不断探索新技术,以期直接利用各种植物枝干的所含物质制造生物能源。     

Analysis of fat-soluble vitamins. XX. Determination of vitamin D in multivitamin preparations. Second collaborative study.

The official first action method for determining vitamin D in multivitamin preparations was modified. The method was collaboratively studied by 7 laboratories, using 6 preparations in oil. The preparations consisted of vitamin D at various levels and at various ratios (in w/w) in vitamin A. Three samples contained cholecalciferol and 3 samples contained vitamin D3 from vitamin D3 resin. After outliers were eliminated by the Dixon test, data were analyzed and averages were compared with amounts of vitamin D known to be in each sample. For samples with vitamin D: vitamin A ratios of 1:0.5, 1:5, and 1:10, the mean vitamin D recoveries were 98.8, 94.6, and 90.7%, respectively. The method has been adopted as official final action.     

Assessment of the stability of pesticides during cryogenic sample processing. 1. Apples.

An assessment of the stability of a large number (106) of pesticides and related compounds during the cryogenic sample processing of apples has been undertaken. For the first time the procedure included an assessment of the losses during the freezing of the fruits, prior to processing. The stability of each pesticide during processing was assessed by comparing the mean recovery for the laboratory-spiked samples with the mean "survival" of the pesticides in cryogenically processed samples. The results clearly demonstrate that the vast majority, 94 of 106, of pesticides were stable during cryogenic processing. Of particular importance was that losses of several pesticides [bitertanol (95%), heptenophos (50%), isofephos (40%), and tolylfluanid (48%)] reported to occur during ambient processing of apples did not occur during cryogenic processing. Losses of dichlofluanid (54%), chlozolinate (22%), and etridiazole (40%), previously reported to occur during ambient processing of apples, were reduced to barely significant levels (10, 17, and 14%, respectively) by cryogenic processing. Small apparent losses for a few of the compounds were attributable to analytical and sample handling difficulties, rather than to losses during processing, and need further investigation.