Formaldehydemissionen beim Herstellungsprozeß von Holzspanplatten

Particle dryers emit varying amounts of formaldehyde. The concentrations differ between 1 and 250 mg formaldehyde per m³ exit air. By thermally induced and hydrolytic reactions only small amounts of formaldehyde emanate during the drying process. In some cases more formaldehyde is emitted from recycled particleboards and resinated particles. Dryers heated by sanding dust often emit large amounts of formaldehyde. The formaldehyde is formed by thermal decomposition of resin parts of the sanding dust. Formaldehyde released during the pressing cycle stems almost exclusively from the binder of the particleboard. UF- and MF-resins emit large amounts of formaldehyde, PF-resins small amounts of formaldehyde and diisocyanate no formaldehyde.     

甲醛清除膜清除人造板和家具中游离甲醛的试验研究

针对目前国内室内游离甲醛浓度严重超标的现状，研制开发了一种清除游离甲醛的新材料——甲醛清除膜。在开发过程中，探讨了其清除人造板游离甲醛的持续性，其载药量、放置方法与用量以及人造板的种类等与清除游离甲醛效果的关系，并进行了清除家具中游离甲醛的试验。     

甲醛清除膜清除人造板和家具中游离甲醛的试验研究

针对目前国内室内游离甲醛浓度严重超标的现状,研制开发了一种清除游离甲醛的新材料——甲醛清除膜。在开发过程中,探讨了其清除人造板游离甲醛的持续性,其载药量、放置方法与用量以及人造板的种类等与清除游离甲醛效果的关系,并进行了清除家具中游离甲醛的试验。     

室内环境中的甲醛污染

本文从五个方面阐述室内环境中的甲醛污染:自然界中的甲醛:室内环境中甲醛的来源:甲醛污染的危害;预防与治理;控制与限量。     

Determination of naturally-occurring formaldehyde in raw and cooked Shiitake mushrooms by spectrophotometry and liquid chromatography-mass spectrometry

The initial objective was to check samples of Shiitake mushrooms for potential contamination with formaldehyde. A small number of UK retail samples were analysed using a spectrophotometric method and were found to produce formaldehyde concentrations ranging from 110-240 mg kg^-1. A more specific method, based on a derivative that could be measured and characterized by LC-MS, confirmed these results. A secondary objective tested the hypothesis that the formaldehyde might be of natural origin. Samples of UK and Chinese Shiitake, verified as being produced without any formaldehyde treatments, were found to produce similar levels of formaldehyde ranging from 100-320 mg kg^-1. Frying for 6 min significantly reduced formaldehyde concentrations, whereas storage for up to 10 days had no effect on the concentrations. The relatively harsh analytical conditions used may have produced some of the formaldehyde measured during extraction, from a number of chemical precursors.     

密胺餐具中甲醛迁移行为的研究

研究了浸泡液类型、浸泡温度、浸泡时间、剪切程度、微波加热时间等五种试验条件对美耐皿餐具中甲醛迁移量的影响,探讨了甲醛单体迁移行为的规律。结果表明,甲醛单体在酸性溶液中更易迁出;在高于80℃时甲醛含量呈现突跃式增长;甲醛迁移量与浸泡时间呈现良好的正比线性关系;样品剪切得越细,浸泡接触面积越大,甲醛迁移量越高;微波炉内加热时间较长时（大于15min）,甲醛迁移量明显增加。     

Formaldehyde content of milk in goats fed formaldehyde-treated soybean oil-meal

Formaldehyde is used in ruminant feeding for different purposes including the protection of dietary proteins from ruminal degradation. The formaldehyde content of milk of goats fed various levels of formaldehyde-treated soybean oil-meal has been determined by using a sensitive HPLC method. Results showed a significant linear correlation between ingested formaldehyde and formaldehyde concentration in milk. About 0.02% of ingested formaldehyde was excreted in milk, as free formaldehyde.     

Formaldehyde emission from particleboard

A test method is described and experimental data are presented which compare formaldehyde emissions from edges and surfaces of particleboards. Surface emissions from boards of different structures and resins are also presented. Porosity of particleboards was measured and related to formaldehyde emission. It was found that porosity of the board is a major controlling factor in formaldehyde emission. It appears that the rate of formaldehyde release from particleboards is a diffusion controlled process.     

食品中甲醛的来源与控制

为了正确认识和解决食品甲醛问题,该文通过收集国内外资料,结合实验室研究工作,对甲醛的危害、食品中甲醛的含量、来源以及国内外对食品中甲醛控制技术的研究进行了综述,重点阐述了食品内源性甲醛的产生及控制。     

除甲醛织物的研制及其性能

针对室内甲醛污染问题,通过对植物多酚与甲醛反应性能的研究,研制了一种除甲醛整理剂。将该整理剂固着在棉织物,并用锌离子处理,研制具有优异的除甲醛功能且耐洗性良好的棉织物。实验结果表明：由多酚类植物提取物与表面活性剂组成的除甲醛整理剂与30μg/ml甲醛溶液在pH值 6.0、温度为60℃条件下按体积1︰1发生反应,12 h后甲醛去除率为74.8%;研制的除甲醛棉织物,甲醛去除率高达91.8%;经10次洗涤后,甲醛去除率达到80%以上。     

Untersuchungen über den Zusammenhang zwischen dem Molverhältnis und der formaldehydabgabe bei Harnstoff-Formaldehyd-Leimharzen

The paper reports on the influence of the molar ratio of urea: form-aldehyde in UF-resins on the formaldehyde emission from resins as well as from particle boards bonded therewith. The results show that a lowering of the formaldehyde content in a UF-resin essentially decreases the formaldehyde emission from the resin as well as from particle boards. In the case of particle boards an almost linear relation between molar ratio and formaldehyde emission was found, independently from the method used for emission measurement. The influence of moisture content and density of particle boards on their form-aldehyde release is furthermore discussed.     

食品中内源性甲醛的研究进展

甲醛是一种禁止在食品中添加和使用的高毒物质.大量调查研究表明许多食品(海产品、果蔬、乳制品等)中含有不同浓度的甲醛,由此引发各种食品中甲醛事件,使其成为消费者关注和学者研究的热点问题.现有研究证明,食品中的甲醛多是由食物本身自发产生的内源性甲醛.内源性甲醛的产生与调控机制研究对开发甲醛调控技术和提高食品安全性具有重要意义.本文综述了近年来食品中内源性甲醛的产生、调控机制和技术的研究进展,分析、提炼了科学问题,在此基础上提出该领域若干研究方向,以期为食品中内源性甲醛的进一步研究提供思路和参考.     

Controlling formaldehyde emissions with boiler ash

Fluidized wood ash reduces formaldehyde in air from about 20 to <1 ppmv. Methanol is removed to a much lower extent. The efficiency of formaldehyde reduction increases with increasing moisture content of the ash. Sorption of formaldehyde to ash can be substantially accounted for by partitioning to the water contained in the ash followed by rate-controlling binding to the ash solids. Adsorption occurs at temperatures of up to 165 degrees C; oxidation predominates thereafter. It is proposed that formaldehyde could be stripped from an air stream in a fluidized bed containing ash, which could then be returned to a boiler to incinerate the formaldehyde.     

有机涂层食品接触材料中甲醛在食品模拟物中迁移规律的研究

目的 研究了有机涂层食品接触材料中毒害物质甲醛在食品模拟物中的迁移规律。方法 根据产品的实际使用条件,以食品模拟物对样品进行模拟浸泡,以乙酰丙酮分光光度法对食品模拟物中甲醛迁移量进行测定。结果 在相同的使用条件下,酸性模拟物中甲醛的迁移量最大;在接触同种食品模拟物时,甲醛的迁移量随着高压灭菌时间的延长和灭菌温度的升高而增加;货架存放时间对甲醛的迁移量无明显影响。结论 通过对甲醛迁移规律的考察,得出了有机涂层食品接触中甲醛的迁移风险。     

鲜香菇中甲醛含量的连续监测分析

目的对河北和北京2个地区来源于市场和生产基地的鲜香菇中的甲醛含量进行连续监测,探究鲜香菇中甲醛含量随时间的变化规律。方法利用高效液相色谱法测定香菇样品中的甲醛含量,并对不同来源样品中的甲醛含量进行对比分析,分析造成含量不同的原因。结果来源于多个产地的北京市售鲜香菇中的甲醛含量较河北市售鲜香菇高;规范管理条件下的鲜香菇中的甲醛含量相对较高,生长态势较好。结论对鲜香菇中的甲醛含量进行持续监测对于监控市场鲜香菇的质量变化、预测预防香菇生产过程中可能出现的病害或误操作等问题具有较强的现实意义。     

THE USE OF FORMALDEHYDE IN RESTEEPING

Small-scale malting trials showed that resteeping in a solution of formaldehyde was more uniformly effective than resteeping in water in reducing rootlet yield and the overall malting loss. The hot water extract, the fermentability of the wort, and the formol nitrogen were the same in worts from malts prepared by resteeping in water or formaldehyde solutions. However, cold water extract was reduced, as was the total soluble nitrogen, by the presence of formaldehyde. The anthocyanogen level in the wort was reduced by about 73% when formaldehyde was used in the resteep liquor. The residue of formaldehyde in the unboiled wort was about I p.p.m. It is considered that, in view of the improved resteeping performance and the expected increase in beer stability resulting from the reduction in anthocyanogens and wort nitrogen, the use of formaldehyde in resteeping is worth evaluating on a larger scale. In addition the use of formaldehyde in the resteep liquor prevented fouling by micro-organisms and resulted in a cleaner malt.     

鲜香菇在不同处理方式下的甲醛含量分析研究

目的检测分析经匀浆、干燥等方式处理鲜香菇中的甲醛含量,反映处理后鲜香菇的生物活性随时间的变化情况,为香菇的储存提供数据支持。方法利用液相色谱法测定香菇甲醛含量。结果匀浆后的鲜香菇中甲醛含量随时间增长而降低,至腐烂后消失。真空包装经高燥处理的香菇中甲醛含量随时间增长呈上升趋势,而真空包装未经干燥处理的香菇,其甲醛含量呈下降趋势。结论通过连续检测鲜香菇中的甲醛含量,验证了香菇中的甲醛来源于其生理活动这一科学论断。基于此,通过检测香菇的甲醛含量判断香菇得生物活性,以观察香菇在贮藏及运输过程中的保质效果。     

Formaldehydemission von Lagenholz und Verbundplatten

For determination of formaldehyde release from plywood and composite boards test procedures applied for the testing of particleboard were examined. The formaldehyde content determined by perforator method permits conclusions to be drawn as to the expected formaldehyde relese. The corresponding correlation is given, the result of comparative examinations of plywood and composite boards from different manufacturers proves that the use of suitable urea formaldes adhesives and special hardeners and upon consideration of some technological pecularities, these materials can certainly be produced with a formaldehyde emission ≦0.1 ppm for their favoured use in furniture manufacturing.     

人造板甲醛释放量检测标准中气候箱法的数学模型探讨

本文在气候箱法的数学模型基础上,探讨了甲醛释放规律、气候箱法的合理性以及应该注意的问题。气候箱法在一定程度上模拟了家具在室内的使用环境,测量得到的数据有重要意义。在分析人造板甲醛释放的气候因素影响后,我们认为家具甲醛释放量的标准中应根据家具的使用环境温湿度,给出相应的甲醛释放量预测数据。     

2005年东莞市食用菌甲醛含量抽查结果分析

目的了解东莞市农贸市场食用菌中甲醛的残留情况。方法对东莞市32个镇区35个农贸市场进行抽查。共抽查130份食用菌,其中干香菇56份,银耳58份,木耳14份,茶树菇2份。结果在干香菇中甲醛检出率100%,平均值164 mg/kg。可能是香菇中甲醛本底值高和生产环节中的工艺所致。木耳、银耳和茶树菇中未检出甲醛。结论食用菌中甲醛的存在有多种因素,在监督中应慎下结论。