梭子蟹贮藏和加工过程中内源性甲醛含量的变化

为探究梭子蟹甲醛的本底含量和来源,采用高效液相色谱法(HPLC)对梭子蟹不同部位、低温贮藏和不同加工过程的甲醛含量进行检测。结果显示,新鲜梭子蟹甲醛本底含量低于10mg/kg,不同部位甲醛含量差异明显,蟹腿肉甲醛含量最高。梭子蟹冷藏和冷冻过程甲醛含量明显下降,醉蟹和蟹糊中甲醛含量上升,而水煮和蒸煮均使甲醛含量增加明显。可见,梭子蟹中可能不存在氧化三甲胺酶生成途径,但仍有类似于鱿鱼等水产品高温分解生成甲醛的反应;腌料中的Fe2+可能促进甲醛的生成。     

海蛰浸泡过程中甲醛含量的变化与分析

鉴于水产品中甲醛有本底含量,应用酚试剂分光光度法测定海蛰在不同温度、不同浸泡时间内的甲醛含量的变化。结果表明,海蛰内甲醛随着浸泡时间延长而逐渐降低,温度高时甲醛消解速度大于温度低时。浸泡一定时间后换水,甲醛浓度下降快,利于海蛰中甲醛的消除。建议海蛰食用前浸泡要多次换水。     

啤酒生产中甲醛残留量控制

从啤酒生产过程中添加不同量的甲醛,用澄清剂代替甲醛,选用低甲醛产量酵母三种方法对啤酒生产工艺进行改进,用乙酰丙酮比色法测定不同工艺生产出来的啤酒中甲醛的含量。通过比较得出:(1)甲醛添加量控制在麦芽用量的150～300mg/kg;(2)添加无毒麦汁澄清剂(3)选用低甲醛产量酵母。以上三种方法可以达到降低啤酒中甲醛含量的目的。     

耐久压烫织物上甲醛释放量测定

甲醛被疑有致癌性,因此耐久压烫织物上释放的甲醛将对人类健康带来危害。在各种不同的条件下,对释放甲醛量的测定是控制甲醛释放的关键。许多已有的方法是静态法,即测定释放甲醛的平衡浓度。而动态法是测定织物贮存和使用过程中实际的释放量。本文发展了在动态条件下测定甲醛释放量的计算机控制设备,它可在不同温湿度条件下测定曝气条件对甲醛释放的影响。结果表明,甲醛释放量与温度和相对湿度之间呈线性关系。     

解决产品中游离甲醛含量超标问题的方法及研究进展

分析了游离甲醛对人体和环境的危害以及不同产品的游离甲醛限量标准。在概述甲醛性质的基础上,分析了皮革中游离甲醛的来源,并介绍了皮革、胶粘剂、板材、纺织等行业解决游离甲醛方法和甲醛捕获剂的研究进展。     

啤酒生产中甲醛残留量控制

从啤酒生产过程中添加不同量的甲醛、用澄清剂代替甲醛、选用低甲醛产量酵母菌3种方法对啤酒生产工艺进行改进,用乙酰丙酮比色法测定不同工艺生产出来的啤酒中甲醛的含量。通过比较得出:(1)甲醛添加量控制在麦芽用量的150mg/kg~300mg/kg;(2)添加无毒麦汁澄清剂;(3)选用低甲醛产量酵母菌3种方法可以达到降低啤酒中甲醛含量的目的。     

皮革中甲醛含量的测定和控制

皮革中甲醛含量有多种测定方法 ,可根据皮革种类不同、实验室条件的差别 ,采用不同方法。因高浓度甲醛具严重危害性 ,故须严格控制 ,研究发现多种方法可显著降低革中甲醛含量。     

甲醛对鱿鱼品质的影响

鱿鱼浸泡甲醛事故屡被报道,这影响了鱿鱼产业的生存与发展。很少有相关文献来细化不同甲醛浓度对鱿鱼品质的影响规律。本研究的目的是研究不同甲醛浓度对鱿鱼感官品质的影响,从而归纳出甲醛影响鱿鱼品质的变化规律。该研究利用电子眼和质构仪仪器来测试甲醛对鱿鱼色泽和质构的影响。本研究能弥补不同甲醛浓度对鱿鱼品质的影响的研究的缺失,为研究有害物质对食品品质的影响提供研究思路。     

酿造过程中甲醛的变化、影响因素及甲醛替代品的初步研究

研究啤酒酿造过程中甲醛变化规律、影响因素及不同甲醛替代品的作用机理，根据可能引起啤酒混浊的物质（多酚、蛋白质）类型不同，可选取不同的甲醛替代品。     

MBTH法测定皮革中游离甲醛

采用萃取法将皮革中游离甲醛分离出来,再将萃取出的甲醛与酚试剂反应生成嗪,嗪在酸性溶液中被高铁离子氧化形成蓝绿色化合物,然后根据颜色的深浅比色测定甲醛含量。用外标法定量时,其线性回归系数（r）为0．9998,RSD为5．02％,在不同的样品中加入不同浓度的甲醛标准溶液,甲醛回收率达到88．6％～93．9％。     

不同纺织品甲醛检测标准对比及检测结果回归分析

对不同纺织品甲醛检测标准进行了对比研究,对各标准间差异对甲醛检测结果的影响和各检测结果间的回归性进行了分析。结果表明:水萃取法的GB(ISO)标准与JIS标准(间苯三酚法)间差异较大。蒸汽吸收法的GB(ISO)标准与JIS标准间差异及与AATCC标准间某些差异较大;甲醛检测结果由高到低依次为:AATCC标准释放甲醛、GB(ISO)标准释放甲醛、GB(ISO)标准游离和水解甲醛、JIS标准游离和水解甲醛;不同标准甲醛检测结果间具有十分显著的线性回归关系,且拟合程度很好。     

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.     

Formaldehydbestimmung nach der WKI-Flaschen-Methode und hiervon abgeleiteten Verfahren

The WKI-method is a simple and practice related technique for determinating formaldehyde release from particleboards and other formaldehyde emitting substances (dispersion paints, wet-strength paper, wall-paper, carpets). A detailed comparison between the WKI-method and the perforator method is given. The results obtained by the WKI-method are less sensitive to the board moisture content. Moreover, with the WKI-method boards with subtle differences in formaldehyde release can be differentiated, where the perforator method fails. Using this method, the formaldehyde release of different formaldehyde emitting materials such as overlay papers can be evaluated. An overview is given to newly developed methods based on the principal of the WKI-method.     

Einfluß der Randbedingungen bei der Bestimmung des extrahierbaren Formaldehyds in Holzspanplatten nach der Perforatormethode

The results show that the determination of extractable formaldehyde from particleboards, using the perforator method, is affected by several marginal factors. Wood materials extractable with toluene and oxidisable with iodine lead to a higher perforator value than that corresponding to the extractable formaldehyde. Moreover, the formaldehyde conteat of particleboards, as measured by the perforator method, depends on their moisture content. Particleboards bouded with different resins with more or less the same perforator value may show different hydrolytic behavior under the influence of temperature and humidity.     

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.     

深色毛皮中游离甲醛含量测定方法的研究

选用了毛皮染色中常用的四种染料配制成系列质量浓度的溶液,然后向溶液中加入已知量的甲醛标准溶液,通过测定加标回收率,分别考察了双空白法和固相萃取脱色法在测定不同颜色、不同色度的萃取液中甲醛含量的准确性.试验表明:在萃取液色度较高时,对甲醛检测有明显干扰,双空白法已不再适用;而经固相萃取小柱脱色后,提取液的本底吸光度大幅度降低,提高了检测的灵敏度和准确性.     

乙酰丙酮法检测皮革制品中甲醛含量的研究

采用乙酰丙酮法在波长为414 nm、乙酰丙酮与甲醛于(40依2)益水浴中显色反应(30依5)min,测定皮革制品中的甲醛含量.研究了乙酰丙酮及馏出液的不同加入顺序对皮革制品中甲醛含量测定的影响,结果表明两种移取顺序对最终结果影响不大,且未发现没有明显规律.     

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.     

HPLC测定乳制品中的甲醛含量

针对奶糖及奶制品的甲醛残留问题,建立了一种灵敏、快速和有效的HPLC-UV检测乳制品中甲醛的方法。牛奶和奶粉样品中甲醛经三氯乙酸(TCA)提取,奶糖另添加乙酸锌和亚铁氰化钾进行辅助沉淀,用1mg/mL2,4-二硝基苯肼(DNPH),在60℃条件下衍生30min后,用HPLC-UV分离测定,外标法定量。该方法对3种奶制品平均加标回收率在95%以上,日内精密度和日间精密度在5%以下,甲醛含量在0.03～4.00μg/mL范围内呈良好的线性关系,检出限和定量限分别为0.03μg/mL和0.10μg/mL,对常见醛类和醇类有较好的抗干扰性。该方法具有操作简单,准确性高,稳定性好,抗干扰性强的特点,是一种测定乳制品中甲醛的有效分析技术。