Phosphorus is the 15th element of the Group V in the third cycle in the periodic table of elements. It plays very important roles in our daily life, involving life, medicine, health, environment, materials, agriculture, etc. It is also indispensable in our daily diet. In this paper, food additives containing phosphorus were introduced in detail, focusing on their main types, application and safety evaluation. Through the discussion about food additives containing phosphorus, we wish to help the readers to have a scientific and fair understanding and comments for food additives. 相似文献
Teaching old dogs new tricks : Recent developments in low‐coordinate phosphorus chemistry reveal the capacity of this element for surprises. For example, P for CR substitution in new phosphaalkynes was used to stabilize purported intermediates in an important synthetic transformation, and also to form new diphosphacyclobutadiene sandwich complexes (see scheme).
Phosphorus is a key plant nutrient and as such, is incorporated into growing biomass in small amounts. This paper examines the influence of phosphorus, present in either acid (H3PO4) or salt ((NH4)3PO4) form, on the pyrolysis behaviour of both Miscanthus × giganteus, and its cell wall components, cellulose, hemicellulose (xylan) and lignin (Organosolv). Pyrolysis–gas chromatography–mass spectrometry (PY–GC–MS) is used to examine the pyrolysis products during thermal degradation, and thermogravimetric analysis (TGA) is used to examine the distribution of char and volatiles. Phosphorus salts are seen to catalyse the pyrolysis and modify the yields of products, resulting in a large increase in char yield for all samples, but particularly for cellulose and Miscanthus. The thermal degradation processes of cellulose, xylan and Miscanthus samples occur in one step and the main pyrolysis step is shifted to lower temperature in the presence of phosphorus. A small impact of phosphorus was observed in the case of lignin char yields and the types of pyrolysis decomposition products produced. Levoglucosan is a major component produced in fast pyrolysis of cellulose. Furfural and levoglucosenone become more dominant products upon P-impregnation pointing to new rearrangement and dehydration routes. The P-catalysed xylan decomposition route leads to a much simpler mixture of products, which are dominated by furfural, 3-methyl-2-cyclopenten-1-one and one other unconfirmed product, possibly 3,4-dihydro-2-methoxy-2H-pyran or 4-hydroxy-5,6-dihydro-(2H)-pyran-2-one. Phosphorus-catalysed lignin decomposition also leads to a modified mixture of tar components and desaspidinol as well as other higher molecular weight component become more dominant relative to the methoxyphenyl phenols, dimethoxy phenols and triethoxy benzene. Comparison of the results for Miscanthus lead to the conclusion that the understanding of the fast pyrolysis of biomass can, for the most part, be gained through the study of the individual cell wall components, provided consideration is given to the presence of catalytic components such as phosphorus. 相似文献
Abstract In recent years attention has been directed toward the synthesis of modified sugars wherein the oxygen atom in the sugar ring is replaced by sulfur, selenium or phosphorus. Synthesis of sugar analogs with phosphorus as the ring heteroatom is interesting from the point of view of their possible biological activity. 相似文献
Abstract Utilizing phosphorus version of the Fritsch-Buttenberg-Wiechell (FBW) reaction, arylphosphaalkynes are prepared from 2,2-dihalo-1-aryl-1-phosphaalkenes, and theoretical calculations were carried out to obtain some basic insight into intramolecular rearrangement in the phosphorus system of interest. [Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental resource: Density functional theory (DFT) and ab initio MP2 calculations.] [Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfer, and Silicon for the following free supplemental files: Additional tables, figures, and references.] 相似文献
