网购密胺餐具的质量分析

目的 测定和分析网购密胺餐具的材质、高锰酸钾消耗量和脱色,研究迁移温度对甲醛迁移量的影响,评估网购密胺餐具的质量。方法 采集网上在售的18批次密胺餐具,通过衰变全反射（Attenuated Total Reflection） 红外法分析密胺餐具和脲醛餐具的特征吸收峰,快速区别密胺餐具和脲醛餐具。依据GB 4806.7-2016《食品安全国家标准 食品接触用塑料材料及制品》对密胺餐具高锰酸钾消耗量、脱色进行了测定和分析。依据GB 4806.6-2016 《食品安全国家标准 食品接触用塑料树脂》对密胺餐具的甲醛迁移量进行测定和分析。结果 脲醛餐具占样品总数44.4%,覆盖密胺涂层的脲醛餐具占样品总数33.3%;11.1%的样品高锰酸钾消耗量不合格;11.1%的样品4%乙酸浸泡液脱色不合格;11.1%的样品甲醛迁移量不合格（4%乙酸,70℃,2h）。结论 本次网上购买的密胺餐具高锰酸钾消耗量、脱色存在不符合GB 4806.7-2016的现象;甲醛迁移量不符合GB 4806.6-2016标准的现象,存在用脲醛餐具替代密胺餐具或是在脲醛餐具上覆盖密胺涂层以次充好的现象。     

竹纤维密胺餐具中三聚氰胺和甲醛在酸性条件下的迁移量测定

目的 通过研究竹纤维密胺餐具中三聚氰胺和甲醛在酸性条件下的迁移规律,讨论影响迁移水平和安全风险的主要因素,对该类产品的安全管理提供建议。方法 采集市场上不同品牌且明确标识含有竹纤维的密胺餐具14种（包括婴幼儿餐具）,选择10%(V/V)乙醇和4%(V/V)乙酸,按照GB 5009.156—2016的方法浸泡餐具,再参照食品安全国家标准GB 31604.15—2016和GB 31604.48—2016开展酸性条件下的迁移试验研究。结果 竹纤维密胺餐具在接触4%(V/V)乙酸时,三聚氰胺和甲醛的迁移水平远高于10%(V/V)乙醇。对单个样品而言,三聚氰胺和甲醛的迁移趋势呈正相关的规律,且长期重复接触酸性较强的食品时迁移量超标的可能性更高。随着使用次数的增加,两者的整体迁移水平逐渐升高,该规律在竹纤维添加量较高的制品中更为明显。结论 竹纤维密胺餐具中的三聚氰胺和甲醛的迁移规律在多次重复使用后仍基本一致;其中三聚氰胺的迁移水平更能反映树脂的分解情况。该类产品长期重复接触酸性食品时三聚氰胺或甲醛迁移量超标的可能性更高,尤其对于婴幼儿产品。应加强标签标识及消费者指导,杜绝使用不合规原料,促进行业良...     

市售密胺餐具的安全性研究

目的 测定和分析市售密胺餐具的感官、甲醛迁移量和三聚氰胺迁移量, 评估市售密胺餐具的安全性。方法 采集了市场在售的30批次密胺餐具, 依据GB 4806.6-2016《食品安全国家标准 食品接触用塑料树脂》对其感官、甲醛和三聚氰胺的迁移量进行了测定和分析。对样品进行均匀性检验, 采用单因素方差分析对结果进行统计分析。结果 23.3%的样品感官出现异常; 33.3%的样品甲醛迁移量超标; 46.7%的样品出现三聚氰胺迁移; 随着浸泡液温度的升高, 无论是甲醛还是三聚氰胺, 其迁移量都有不同程度的增加; 售价较低的样品出现问题率更高。结论 目前市场上密胺餐具的质量令人担忧, 不同价格与不同来源的餐具质量存在较大差异。消费者应选择外表光滑、平整的餐具, 同时尽量不要在高温或酸性条件下使用密胺餐具。     

学校食堂在用密胺和不锈钢餐具检测及风险分析

目的 通过对学校食堂在用密胺和不锈钢餐具进行检测分析,并参照相关国际标准与国家标准对检测结果进行分析,以评估学校食堂在用密胺和不锈钢餐具的风险状况,为建立风险防范措施及优化现行标准提供理论依据。方法 本次检测通过对密胺餐具中甲醛迁移量、三聚氰胺迁移量;对不锈钢餐具中铅迁移量、砷迁移量、镉迁移量和镍迁移量六项指标,对食堂抽取的100批次密胺在用餐具和100批次不锈钢在用餐具样品进行风险分析。结果 本次研究共发现在用问题餐具共72批次,占比36.0%。其中在用问题密胺餐具55批次,占密胺餐具总量的55.0%;问题不锈钢餐具17批次,占不锈钢餐具总量的17.0%。密胺餐具不合格项目主要为甲醛和三聚氰胺(4%乙酸,水)的迁移量超标,不锈钢餐具不合格项目主要为铅、镉元素的迁移量超标。结论 食堂应制定密胺餐具相应的使用管理规范,设定密胺餐具的使用年限为1年以内,同时规范餐具的消毒、清洗等操作,从而有效地降低甲醛和三聚氰胺的迁移风险;应加强不锈钢餐具原料供应链管理,从源头降低风险。     

一种筛查一次性竹筷中二氧化硫特定迁移量的试验方法

采用一次性竹筷的强制性方法标准GB 31604.32—2016测量产品的二氧化硫含量。选用食品接触材料国家标准新体系GB 5009.156—2016通用的6 dm2接触面积对应1 L浸泡液的比例构建模型,估算得到该产品的二氧化硫特定迁移量。在《食品安全国家标准食品接触材料及制品二氧化硫特定迁移量的测定》和《食品安全国家标准食品接触用竹、木和软木材料及制品》正式发布实施以前,可以通过将本筛查方法得到的二氧化硫特定迁移量与《食品安全国家标准食品接触用竹、木和软木材料及制品》中规定的限量值进行比较,从而判断该产品的二氧化硫特定迁移量是否合格。     

蜜胺餐具中三聚氰胺单体的迁移规律研究

结合蜜胺餐具的实际使用情况,选用合适的食品模拟物进行迁移实验,采用LC-MS/MS法测定三聚氰胺迁移量,研究蜜胺餐具中三聚氰胺单体的迁移规律。重点考察了食品模拟物种类、接触时间、接触温度、乙酸浓度、乙醇浓度、重复使用和微波加热等迁移条件下蜜胺餐具中三聚氰胺迁移量的变化情况。结果表明酸性食品和牛奶中的三聚氰胺迁移风险较高,且需控制蜜胺餐具的使用温度、盛放时间、重复使用次数及微波加热功率和时间以降低密胺餐具中三聚氰胺迁移风险。     

网购折叠硅胶水壶产品质量研究

目的 研究网购折叠硅胶水壶产品质量相关参数。方法 参照GB/T 11416—2002《日用保温容器》检测倾倒试验和手把及壶体的连接强度,参照GB/T 531.1—2008《硫化橡胶或热塑性橡胶 压入硬度试验方法 第1部分: 邵氏硬度计法(邵尔硬度)》检测样品硬度;参照GB 28482—2012《婴幼儿安抚奶嘴安全要求》检测挥发性物质,按照GB 31604.2—2016《食品安全国家标准 食品接触材料及制品 高锰酸钾消耗量的测定》检测高锰酸钾消耗量,按照GB 31604.8-2016《食品安全国家标准 食品接触材料及制品 总迁移量的测定》检测总迁移量,按照GB 31604.9—2016《食品安全国家标准 食品接触材料及制品 食品模拟物中重金属的测定》中第一法测定硅胶水壶中的重金属（以Pb计）。结果 倾倒试验和手把及壶体的连接强度结果均满足标准要求,热水老化和热空气老化处理后大部分样品硬度变大;高锰酸钾消耗量、总迁移量和重金属测试结果都很低,远小于国家标准限量值,合格率为100%。挥发性物质含量超出参考值比率高达86.6%,且66.6%在2倍以上。结论 热老化会使样品硬度发生变化;挥发性物质含量较高,应引起监管部门重视,督促企业提高产品质量。     

食品安全国家标准GB 31604.1—2015实施

正GB 31604.1—2015《食品安全国家标准食品接触材料及制品迁移试验通则》已于2016年9月22日正式实施。该标准为国家强制性标准,规定了各类食品接触材料和制品在进行迁移试验时,食品模拟物、试验时间和温度以及面积体积比(S/V)的选择原则。新标准GB 31604.1—2015借鉴了美国、欧盟等发达国家的标准和检测经验,规定食品接触材料迁移测试     

食品接触材料及制品总迁移量的测定方法探讨

总迁移量是食品接触材料应满足的基本性能之一,表征的是食品接触材料向食品中可迁移的非挥发性物质的总量。食品接触材料及制品中总迁移量的测定按照国家标准GB 31604.8-2016《食品安全国家标准食品接触材料及制品总迁移量的测定》方法测定。选取2个厂家的2种不同的白酒瓶盖内塞进行总迁移量的测定,从而验证GB 31604.8-2016方法的适用性。     

食品接触用塑料制品安全国家标准与检验问题探讨

食品接触用塑料制品与卫生安全息息相关, 新版本食品安全标准发布后, 有关安全标准及其产品检验过程中的一些问题, 引起了人们关注。本文对比分析了食品接触用塑料制品新旧版本食品安全标准的主要区别, 阐述了GB 4806.6-2016 《食品安全国家标准食品接触用塑料树脂》和GB 4806.7-2016《食品安全国家标准食品接触用塑料材料及制品》主要技术要求及其检验项目, 并以聚对苯二甲酸乙二醇酯(polyethylene terephthalate, PET)无汽饮料瓶、聚乙烯(polyethylene, PE)食品袋、密胺调料酱罐制品为例详细探讨了检验过程中迁移试验条件选择等问题, 以期为食品接触用塑料制品的生产企业、检验机构等提供参考。     

Migration of formaldehyde and melamine monomers from kitchen- and tableware made of melamine plastic

Migration of one or both formaldehyde and/or melamine monomers was found in seven of ten tested melamine samples bought on the Danish market. The samples were a bowl, a jug, a mug, a ladle, and different cups and plates. No violation of the European Union-specific migration limits for melamine (30 mg kg^-1) and formaldehyde (15 mg kg^-1) was found after three successive exposures to the food stimulant 3% acetic acid after 2 h at 70°C. To investigate the effects of long-term use, migration tests were performed with two types of cups from a day nursery. Furthermore, medium-term use was studied by ten successive exposures of a plate to 3% acetic acid for 30 min at 95°C. The results indicate that continuous migration of formaldehyde and melamine takes place during the lifetime of these articles. The molar ratio of released formaldehyde to melamine was seen to decrease from 12 to about 5. This indicates that, first, the migration of residual monomers is most important, but in the long-term, breakdown of the polymer dominates. Two CEN methods were used to determine the concentration of monomers: a spectrophotometric method for formaldehyde and a UV-HPLC method for melamine.     

An attempt to estimate service terms of tableware made of amino resins

This study presents a first attempt to estimate the service terms of food contact articles made of melamine/formaldehyde and urea/formaldehyde plastics. This was achieved by following the continuous release of formaldehyde into food simulants throughout the use phase until the levels of formaldehyde migration exceeded the specific migration limit (SML), or samples were damaged and not suitable for further tests. Two test conditions were established to follow customary practices as much as possible: scenario 1, successive washing; and scenario 2, alternate courses of exposure and washing. Real melamine tableware showed conformity to the SML of formaldehyde over the course of 1500 successive washings; the estimated service term was 750 days, or about 2 years. Moreover, this service term agreed well with that found in real practice. When washing urea/formaldehyde tableware with sponges, the levels of formaldehyde migration remained below the SML, but samples eventually fractured. In the case of scrubbing pads, the levels of formaldehyde migration constantly increased and ultimately exceeded the SML. Scenario 2 resulted in accelerated migration of formaldehyde, and the SML was exceeded more rapidly than in scenario 1. Because surface roughening occurred during customary use and also during washing with scrubbing pads, it was necessary to adopt reduction factors to take into account the effects of handling when calculating service terms of articles. The results showed reduction factors ranging from 1 to 3, depending on test conditions (scenario 1 or 2) and anticipated use conditions (hot fill or use at ambient temperature). Thus, the estimated service terms of urea formaldehyde products were 117 and 175 days under hot fill and ambient conditions, respectively. These results corresponded with service terms observed in real practice, which were reported to be in the ranges of 3–4 and 6–7 months, respectively. Taking into account the time and expenses consumed during experiments, scenario 1 (successive washing with scrubbing pads) would be recommended as an appropriate method for following the migration of formaldehyde over repeated use phases and for estimating the service terms of amino-resin-based articles for food contact use.     

Migration of formaldehyde and melamine from melaware and other amino resin tableware in real life service

ABSTRACT

The migration of formaldehyde and melamine monomers has been measured on 90 samples of plastic tableware in three different situations – new articles, already used articles and artificially aged articles – by using simulant, contact times and temperatures prescribed by Commission Regulation (EU) No. 10/2011. Formaldehyde was determined by ultraviolet spectroscopy analysis of the coloured complex obtained by reaction with chromotropic acid. Melamine was measured by an ultra high performance liquid chromatography method. Fourier Transformed – Infrared Analysis was applied to characterise the plastic. The results highlighted the presence of different amino resins based on formaldehyde-melamine, urea-formaldehyde or melamine-urea-formaldehyde with different migration behaviour. The migration of monomers was related to progressive degradation of the resins. Ageing studies demonstrated that the potential degradation of the resins and the consequent migration of the monomers may continue throughout the service life of the product. The specific migration limit (SML) of melamine was exceeded after ageing.     

Migration of melamine and formaldehyde from tableware made of melamine resin

Migration of melamine and formaldehyde into food-simulating solvents from cups made of melamine resin was studied under various conditions. Little migration of melamine was observed in any unused cups kept at 60 degrees C for 30 min, room temperature (26 degrees C) for 1 h or cooled at -20 degrees C for several days. Migration of both compounds was strongly affected by heating and acidity. The highest migration of melamine into 4% acetic acid used as a food-simulating solvent was 42.9 +/- 7.2 ppm when the migration test was repeated seven times at 95 degrees C for 30 min. In this time, the migration of formaldehyde was 14.2 +/- 0.6 ppm into the solvent. The molecular ratio of the migration amount of formaldehyde to melamine decreased according to the formula Y = 9.15X-0.813 over seven repetitions of the test, and was maintained at about 1.6 between the 10th and 20th repetitions. The inner surface of the cups became tarnished during the repetition of the test and their roughness increased from 1 micron before the test to 2.5-5 microns after 20 repetitions of the test. Migration of melamine from the cups being used at a cafeteria was 0.4 +/- 0.5 ppm, but that of formaldehyde was undetectable when the cups were kept at 60 degrees C for 30 min with 4% acetic acid.     

Release of formaldehyde and melamine from tableware made of melamine-formaldehyde resin

The relationship between the concentrations of formaldehyde and melamine released into 4% acetic acid from dishes and bowls made of melamine-formaldehyde resin was determined. The average concentrations in the migration solution after the sample had been treated at 60, 80, and 95 degrees C for 30 min with 4% acetic acid were 0.0 +/- 0.1, 0.5 +/- 0.4 and 3.0 +/- 2.2 ppm, respectively for formaldehyde and 0.04 +/- 0.07, 0.21 +/- 0.20 and 1.19 +/- 1.18 ppm, respectively for melamine. The correlation between the concentrations of formaldehyde and melamine released at 95 degrees C was y=0.4858x-0.2728 (r=0.8860), where y is melamine concentration (ppm), x is formaldehyde concentration (ppm) and r is the correlation coefficient. The molar concentration ratios of formaldehyde to melamine (F/M ratio) were 15.4 +/- 11.6 at 80 degrees C and 14.9 +/- 10.1 at 95 degrees C. Hence the release of both migrants was affected by temperature but the F/M ratio was not affected. The release of both compounds was was increased on repetition of the migration test at 95 degrees C but their concentrations remained constant after the tenth and seventeenth repetitions of the treatment. During this period, the F/M ratio decreased according to the equation 1n y=-1.4344 1n x+3.7814 (r=-0.9984) for a sample before the tenth repetition of the treatment and remained between 1.7 and 1.9 after the twelfth repetition, where y is the F/M ratio and x is the number of repetitions of the treatment.     

杨木单板层积材单板斜接质量胶接工艺探讨

单板纵向接长是单板层积材(LVL)生产的核心环节,单板斜接质量的好坏直接影响生产效率、产品外观质量和内在强度。本文探讨了非结构用杨木LVL产品中的单板斜接生产工艺改进方法,由使用酚醛树脂胶改为三聚氰胺改性脲醛树脂胶,并验证了其可行性。