密胺餐具的鉴别及其三聚氰胺和甲醛迁移风险调查

目的对密胺餐具中三聚氰胺和甲醛迁移量进行调查研究,并对数据进行分析。方法在上海的企业和消费市场采集密胺餐具共40份,采用红外光谱法进行材料鉴别,依照GB 4806.7—2016《食品安全国家标准食品接触用塑料材料及制品》和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》进行迁移试验,测定三聚氰胺和甲醛迁移量。结果密胺餐具存在材质未标识、标识不清或标识有误的现象;脲醛树脂中三聚氰胺和甲醛的迁移量均高于密胺树脂,且迁出量与温度呈正相关。结论脲醛树脂应用于餐具存在风险,国家标准中有必要增加密胺材质鉴定检测方法。     

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...     

密胺餐具中三聚氰胺迁移量影响因素分析

目的 对密胺餐具中三聚氰胺迁移量影响因素进行分析。方法 以水、4%乙酸、50%乙醇3种溶剂为浸泡液, 在不同温度下浸泡不同时间, 其浸泡液过滤并用高效液相色谱-质谱法测定, 外标法定量。结果 密胺餐具中三聚氰胺的迁移量和迁移时间、迁移温度、迁移浸泡液相关。三聚氰胺的迁移量随着迁移时间增加、迁移温度升高而升高, 且在酸性模拟溶液中三聚氰胺的迁移量最大。浸泡液为4%乙酸时, 在100 ℃下浸泡1 h时, 三聚氰胺迁移量达到最大值, 密胺碗、饭勺、筷子的迁移量分别为1.94、1.35、1.61 mg/kg。结论 密胺餐具中的三聚氰胺在高温、酸性条件下易迁移, 建议消费者在使用过程中尽量避免在高温、酸性条件下使用, 选择大品牌的厂家生产的有QS标示的产品。     

密胺餐具中甲醛迁移量的不确定度评定

采用紫外分光光度法测定了密胺餐具中甲醛迁移量,分析了甲醛迁移量测定过程中不确定度的来源,并对各个不确定度分量进行了量化且计算出合成不确定度,根据JJF1059规范要求给出不确定度表达式。     

学校食堂在用密胺和不锈钢餐具检测及风险分析

目的 分析学校食堂在用密胺和不锈钢餐具风险状况.方法 通过检测密胺餐具中甲醛迁移量、三聚氰胺迁移量,不锈钢餐具中铅迁移量、砷迁移量、镉迁移量和镍迁移量6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 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...     

分光光度法测定密胺餐具中甲醛的不确定度评估

依据GB/T5009.61-2003对密胺餐具中有害物质甲醛的分光光度法的不确定度进行研究。建立数学模型,量化各个来源对总的不确定度影响,计算得出分光光度法测定密胺餐具中甲醛的合成不确定度和扩展不确定度。     

层次分析法在密胺餐具安全风险评估中的应用

本研究以密胺餐具为研究对象,运用层次分析法对密胺餐具进行安全风险评估。结果表明:使用不当在密胺餐具安全风险评价中占较为重要的地位,产品自身的质量问题次之。作为日用品的密胺餐具,如果使用不当很可能会给消费者身体健康带来风险。     

仿瓷餐具高温下可能释放出三聚氰胺

有关专家称,市民餐桌上色彩鲜艳、款式多样的仿瓷餐具（又名密胺餐具）在高温下也可能释放出三聚氰胺。据悉,仿瓷餐具的主要成分是密胺树脂,而密胺树脂就是由三聚氰艘和甲醛聚合而成的。质量较好的密胺餐其中的三聚氰胺和甲醛在一般情况下是稳定的。     

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。     

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。     

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 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.     

Effects of microwave heating on the migration of substances from melamine formaldehyde tableware

Melamine formaldehyde (MF) tableware, after undergoing repeated heating in a microwave oven for 1, 2, 3 or 5 min, was tested for migration into 3% (w/v) acetic acid, a food simulant. Overall migration (OM) consistently increased with an increasing number of heating/washing cycles, while formaldehyde was found at low concentrations or was not detectable. Unexpectedly, the 1-min series caused the most rapid increase in OM; the European Union regulatory limit of 10 mg dm^–2 was exceeded after 25 cycles. The number of cycles required to reach the OM limit rose to 29 and 67 for the 2- and 3-min series, respectively. Only 37 cycles were needed in the case of the 5-min series; however, the cumulative exposure time to microwave irradiation was relatively close to that of the 3-min series. These findings indicate that microwave heating affects the migration of MF in a significantly different manner as compared with conventional heating reported in previous studies. Fourier transform infrared spectroscopy (FTIR) spectra of MF after completing the microwave heating series show that the plastic was not fully cured, as evidenced by the absence of methylene linkages. The majority of migrants obtained from OM tests consisted of low molecular weight methylol melamine derivatives. The results indicate that microwave heating allowed demethylolation, addition and condensation reactions to occur, which was not the case when using conventional heating. This study demonstrates that microwave heating for 1–2 min in a repeated manner is of high concern in terms of consumer health. It was found that the service terms of melamine ware under microwave heating were drastically reduced, by more than 10-fold, as compared with the service terms under conventional heating. Hence, it is strongly recommended that manufacturers of MF articles provide instructions for use, e.g. “Do not use in microwave”, which should be clearly visible to consumers and not easily detachable.     

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.     

Survey of counterfeit melamine tableware available on the market in Thailand,and its migration

A simple measurement of sample density by adopting the principles of buoyancy could help screen counterfeit melamine ware if the density was below 1.50?g?cm^?3. However, samples with a density exceeding 1.50?g?cm^?3 were not necessarily made from melamine formaldehyde. FTIR analysis showed that all counterfeit products were made of urea formaldehyde and coated on the food-contact side with melamine formaldehyde, a tactic probably intended to cover up the true product features. The overall migration of real and counterfeit melamine samples complied with both European Union and Thai regulations, as the exposure layers in both cases were melamine formaldehyde. Formaldehyde migration failed to comply with Thai standards, but this was not the case for European Union standards. However, the results showed a significant inconsistency between individual items of the same brand and between individual exposures of the same test specimen. This indicated the inherent inhomogeneity between individual items, which mainly resulted from the manufacturing process: for instance, insufficient temperature and time to obtain complete polycondensation of monomers. Therefore, it is recommended that constant surveillance be conducted on melamine articles available in the marketplace in terms of quality and safety.