Nitrate and water-soluble carbohydrate

Methods estimating nitrite, therefore, must use an e ctractant such as water, followed by immediate analysis. 

Another method used for nitrate determination on dried and milled herbage employs the nitrate selective electrode. One of the first published methods was that of Paul and Carlson (1968). Other anions, especially chloride, can interfere. These authors removed chloride with silver resin, but Barker ef al. (1971) omitted the resin because it tended to foul the electrode and cause excessive drift. Normally the Cl N03 ratio is so low as not to interfere, but saline precipitation from coastal plots could affect this. The method was further modified to allow storage of extracts for up to 64 h by adding a preservative of phenyl-mercuric acetate and dioxane, both very toxic (Baker and Smith, 1969). This paper mentions the need to change the electrode s membrane, filling solution and liquid ion exchanger every 2 months to minimize chloride interference. It is easy to overlook electrode maintenance between batches of nitrate analyses, and this can lead to errors and sluggish performance. 

The method was extended from plants to include soils and waters by Milham ef al. (1970). They point out that nitrate reductase activity in fresh plant samples often causes a rapid decline in nitrate content, so samples collected from remote sites should be frozen in dry ice. A trace of chloroform was used to protect soil and water samples before freezing. We are now more aware of the harmful effects of chloroform inhalation and suggest immediate freezing without preservative and analysis within a few days as a safer alternative - especially with student projects. 

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See the discussion with references in Chapter 4 Nitrate and water soluble carbohydrate. Soil extracts low in colour may also be analysed by this procedure by taking a 10-ml scoop of fresh or thawed soil. The official Bran-rLuebbe AutoAnalyzer method for nitrate and nitrite in soil, plant and fertilizer extracts is reproduced with permission in Appendix 5. 

Benzoic acid solution, saturated - see Chapter 4 Nitrate and water soluble carbohydrate, for details. 

See the discussion in Chapter 4 Nitrate and water soluble carbohydrate. Note the extract obtained for determining nitrate in plants, which is also in saturated benzoic acid, may be used for the water soluble carbohydrate determination if diluted x2. 

Solution combustion synthesis makes use of salts, such as nitrates, metal sulfates and carbonates, as oxidants and, reducing reagents, fuels such as glycine, sucrose, urea, or other water soluble carbohydrates. Nitrate acts as an oxidizer for the fuel during the combustion reaction. The powder can be a pyrolysed product of a single phase, but usually it is a combination of metal oxides and in some cases it needs subsequent heat treatment to form single-phase products, which are usually the results required in this process. 

Schaumberg et al. [58] made a qualitative infrared spectroscopic study of water-soluble compounds extracted from sewage sludge/oil mixtures which were being incubated in the laboratory for 100 weeks at 25°C, and the results are presented. It was found that there was a pattern to the microbial decomposition of anaerobically-digested sewage sludge which involved the disappearance of carbohydrate, protein, sulphonate, and/or sulphate compounds, coupled with the appearance of carboxylates and nitrates. 

Lanthanide chlorides (473) and nitrates (474,475) have been used as aqueous LSR for investigating the structures of a number of carbohydrates. Shifts induced by Ln " ions in the proton spectrum of methoxyacetate have been discussed. (476) The water-soluble Eu complexes of pyridoxalideneaspartic acid and o-vanillideneaspartic acid have been suggested as suitable shift reagents. They have been tested with aqueous solutions of amino-acids and peptides. (477)... 

Hi) Non-covalent approaches to gold glyconanoparticles. Other protocols have been reported for the synthesis of GNPs in which the carbohydrates are non-covalently attached to the metal eluster. Saceharide-modified hyperbranched poly(ethylenimines) were used to elaborate eopper, silver, gold, and platinum nanoparticles. 12-a-C-Ribofuranosyl and ribopyranosyl dodecanoic acids were heated with silver nitrate in dilute alkaline solution to afford water-soluble 15 nm silver GNPs. ... 

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