67879-60-1Relevant articles and documents
preliminary aldehyde (C 2-C 10) propylene glycol acetal synthetic method (by machine translation)
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Paragraph 0009; 0010, (2016/10/07)
The invention discloses a synthetic method of low-grade aldehyde (C2-C10) propylene glycol acetal. A target object is prepared from low-grade aldehyde (C2-C10), 1, 2-propylene glycol, anhydrous calcium chloride and p-toluenesulfonic acid which are reacted in the method. By adopting the method disclosed by the invention, the reaction is free from byproducts and pollution, the product purity and the product recovery rate are high, the cost is low, the efficiency is high and the fragrance is good. Through simple stirring reaction, the content of the acetal can reach condensation over 98%, and the method is applicable to mixing various high-grade essences and has a considerable effect of increasing the stability and temperature resistance of an essence finished-product.
Identification of 1,3-dioxanes and 1,3-dioxolanes as malodorous compounds at trace levels in river water, groundwater, and tap water
Romero, Jordi,Ventura, Francesc,Caixach, Josep,Rivera, Josep,Gode, Llui Xavier,Ninerola, Josep Ma.
, p. 206 - 216 (2007/10/03)
A study of organic compounds imparting odor problems in river waters and groundwaters has been conducted. The Tordera aquifer located in Barcelona and Girona (NE Spain) is the water supply reserve for many seasonally crowded villages on the coast. Closed loop stripping analysis (CLSA) and flavor profile analysis (FPA) have been employed as analytical tools to identify the compounds responsible for the odor complaints. The feasibility of purge-and- trap (P and T) has also been evaluated. The 2-alkyl-5,5-dimethyl-1,3-dioxanes and 2-alkyl-4-methyl-1,3-dioxolanes were the most significant compounds identified in river water and groundwater with a threshold odor of 10 ng/L for 2-ethyl-5,5-dimethyl-1,3-dioxane (2EDD), the most malodorous compound. The analyses were carried out by HRGC/MS, and the synthesized 1,3-dioxanes and dioxolanes were characterized by CI-MS and EI-MS/MS techniques. A company, currently manufacturing saturated and unsaturated polyester resins, located in the upper course of the river, produced these compounds as byproducts during the synthesis of resins. The pollution by dioxanes and dioxolanes affected all the aquifer and slowly diminished to the ppt levels when the company was forced to correctly treat their wastewaters. Additional examples of the presence of dioxanes and dioxolanes in wastewaters of other resin plants and also tap water of Barcelona are shown. A study of organic compounds imparting odor problems in river waters and groundwaters has been conducted. The Tordera aquifer located in Barcelona and Girona (NE Spain) is the water supply reserve for many seasonally crowded villages on the coast. Closed loop stripping analysis (CLSA) and flavor profile analysis (FPA) have been employed as analytical tools to identify the compounds responsible for the odor complaints. The feasibility of purge-and-trap (P&T) has also been evaluated. The 2-alkyl-5,5-dimethyl-1,3-dioxanes and 2-alkyl-4-methyl-1,3-dioxolanes were the most significant compounds identified in river water and groundwater with a threshold odor of 10 ng/L for 2-ethyl-5,5-dimethyl-1,3-dioxane (2EDD), the most malodorous compound. The analyses were carried out by HRGC/MS, and the synthesized 1,3-dioxanes and dioxolanes were characterized by CI-MS and EI-MS/MS techniques. A company, currently manufacturing saturated and unsaturated polyester resins, located in the upper course of the river, produced these compounds as byproducts during the synthesis of resins. The pollution by dioxanes and dioxolanes affected all the aquifer and slowly diminished to the ppt levels when the company was forced to correctly treat their wastewaters. Additional examples of the presence of dioxanes and dioxolanes in wastewaters of other resin plants and also tap water of Barcelona are shown.