【作者】 孟迪；

【导师】 龙玲；

【作者基本信息】 中国林业科学研究院 ， 木基复合材料科学与工程， 2012， 硕士

【摘要】 饰面人造板广泛应用于室内装饰装修和家具制作，与人们的工作生活环境密切相关。在人造板饰面材料生产过程中，含有铅、镉、铬、汞等重金属的化合物可能作为着色剂、稳定剂、防虫剂、阻燃剂等被添加到其中，在板材使用过程中微量的重金属可能从饰面材料表面溶出或随着表面材料脱落而被误食进入人体，从而对人体造成危害。目前对该方面的研究很少，尚未建立检测方法和限量要求。因此，急需对人造板饰面材料中重金属含量进行限制，建立相关检测方法标准，确保其使用安全性。本论文以涂料实木复合地板、聚氯乙烯（PVC）薄膜饰面人造板、三聚氢胺甲醛树脂浸渍胶膜纸饰面人造板三种板材的饰面材料为研究对象，进行样品制取和微波消解等前处理，分别以原子吸收光谱法（AAS）和电感耦合等离子发射光谱法（ICP-AES）测定重金属铅、镉、铬、汞四种元素，以二苯碳酰二肼（DPC）分光光度法测定六价态铬（Cr6+）元素，为人造板重金属检测方法标准的制定提供相关数据和科学依据。研究结论如下：1.确立样品制备方法。对于涂料人造板和浸渍胶膜纸饰面人造板，采用刮刀刮取表面涂料和浸渍胶膜纸，应避免刮到基材的纤维屑，将刮取的样品收集到研钵内，研磨混和均匀，作为待处理样品。对于PVC薄膜饰面人造板，采用刀片辅助揭取人造板板材表面的PVC薄膜，刮净其上沾带的纤维，再进行剪切粉碎，制得样品。2.确定微波消解法作为样品的前处理方法。较佳处理条件为：称样质量0.1g，消解温度225℃，消解压力55bar。选择硝酸和过氧化氢为消解试剂，消解液体积为10mL，硝酸：过氧化氢=3:1（体积比）。3.建立微波消解—原子吸收光谱法测定人造板饰面材料中铅镉铬汞总量的方法。四种元素的检出限为0.00003mg/L⁰.15mg/L，加标回收率为95.52%¹06.30%，线性范围为0⁵μg/mL，测定实际样品时，铅、铬元素的相对标准偏差小于10%，镉元素相对标准偏差小于1.5%，汞元素相对标准偏差小于50%。4.建立微波消解—电感耦合等离子发射光谱法测定铅镉铬汞总量的方法。四种元素的检出限为0.0006mg/L⁰.003mg/L，加标回收率为93.8%¹09.19%，线性范围为0⁵μg/mL，测定实际样品时，铅、镉、铬元素相对标准偏差小于1.5%，汞元素相对标准偏差小于5%。5.确立二苯碳酰二肼（DPC）分光光度法测定人造板饰面材料中Cr⁶⁺元素含量。以氢氧化钠和无水碳酸钠作为样品消解液，采用高速离心分离机分离消解后的乳浊液，用分光光度计在540nm处测定反应溶液的吸光度。该方法线性范围为0¹.5mg/L，线性相关系数R为0.9995，相对标准偏差均小于1.1%。6.初步研究铅、镉元素在溶液中的迁移状况，表明温度、溶液酸度和样品在溶液中的浸泡时间对重金属的迁移量有较大影响。浸渍胶膜纸、PVC薄膜、饰面涂料三种样品中，浸渍胶膜纸中的重金属元素更易向溶液中迁移；铅、镉、铬、汞四种元素中，铅更易向溶液中迁移。7.通过对来自不同厂家的27份人造板饰面材料样品的分析，表明其中80%的样品中的铅、镉、铬元素含量小于100mg/kg，重金属含量较高的样品比例较小，仅1种样品检测出汞元素。更多还原

【Abstract】 Wood-based panels are widely used in decoration or manufacture of woodenproducts.Toxic heavy metals are mainly in the surface decorative materials of wood-basedpanels.But there is no limitation for total content of the toxic heavy metals such as leadcadmium chromium(including hexavalent chromium) mercury in our national limitationstandard of indoor decorating and refurbishing materials.A method was developed fordetermining trace metals lead cadmium chromium(including hexavalent chromium) mercuryin decorative paint、polyvinyl chloride、melamine-impregnated paper. The microwave-digestiontechnique was used in the decomposition of the samples. The content of the four metals weredetermined by atomic absorption spectrometry and induce coupled plasma atomic emissionspectrometry.Diphenyl hydrazine spectrophotometric was adopted for determining thehexavalent chromium content. The conclusions are as follows:1. Scrapping off the decorative coating from the test sample with a suitable blade,collecting the scraps into a mortar and mixing them as proportioned samples.Taking off thepolyvinyl from the surface of the panel,and scrapping off all the fibers adhered to the reversesides of the penal,then cut the PVC samples into small pieces.2. It was adopted microwave digestion to decompose the samples,and confirmed thecondition of microwave digestion.The sample mass for digestion is0.1g,the temperature is225centigrade,the pressure is55bar.Adding7.5ml nitrid acid and2.5ml hydrogen peroxidebefore the digestion process.3. The detection limit of the four elements by atomic absorption spectrometry is0.00003mg/L~0.15mg/L.The recovery rate is from95.52%to106.30%.The liner range is0~5μg/ml. The relative standard deviation of lead and chromium is less than10%while theRSD of cadmium is less than1.5%,and the RSD of mercury is less than50%,when testsamples. 4. The detection limit of the method as determined by ICP-AES is among0.0006mg/L and0.003mg/L.The standard curves were linear over the range of0to5μg/ml. The recovery rangedfrom93.8%to109.19%. The relative standard deviation of lead cadmium and chromium is lessthan1.5%,and the RSD of mercury is less than5%,when test samples.5. Samples for detect Hexavalent chromium was digested with alkali digestion anddetermined by UV-vis spectrophotometric analysis.Sieving the PVC with a500μm sieve,andsieving the paint and the membrane coating with250μm sieve. After the alkali digestion,separate the sample’s emulsion with high-speed centrifuge.With a color reagent (DPC) tochelated with Cr(VI), the solution was finally detected by a UV–vis spectrophotometer at awavelength of540nm which is the basis of analyzing Cr(VI) quantitatively.The linear range isfrom0mg/L to1.5mg/L,the correlation coefficient is up to0.9995,the relative standarddeviation is less than1.1%.6. Through the analysis of27samples of wood-based panels’ surface decorativecoatings,it was determined that the concentration of lead cadmium chromium is less than100mg/kg in more than80%of the samples,and a small proportion of the samples were detectedwith high concentration metals.The concentration in samples was very a little.It was knownthat the migration of heavy metals from material in solution was greatly influenced by thesolution temperature、acidity grade and soaked time.By comparison of the total content and thecondition migration amount of heavy metal,it was concluded that the heavy metals inmelamine-impregnated paper were more capable to remove into solution and the lead in fourmetals elements was more likely to move into the solution.更多还原