The analysis of saturated and aromatic mineral oil hydrocarbons in dry foods and from recycled paperboard packages by online HPLC–GC–FID

ABSTRACT

The purpose of this study was to determine the concentrations of mineral oil hydrocarbons in dry foodstuffs packed in recycled paperboard, which were imported from different foreign countries to Germany. After collection, mineral oil saturated hydrocarbons (MOSH) and mineral oil aromatic hydrocarbons (MOAH) in dry foodstuffs and recycled paperboard were analysed using online coupled high-performance liquid chromatography–gas chromatography–flame ionisation detection (online HPLC–GC–FID) far before the end of the shelf life of the samples. Our results showed that recycled paperboard has MOAH content higher than that of dry foodstuffs. The proportion of MOAH within total mineral oil hydrocarbons was determined to be 7–45% in dry foodstuffs and 4–48% in paperboard. In addition, 29% of the products were found to contain over 1.00 mg/kg MOAH, with a maximum of 2.72 mg/kg in oatmeal. White colour recycled paperboard contained lower amounts of MOSH and MOAH than that of brown and grey colour recycled paperboard. The MOSH concentration in dry foodstuffs ranged from 0.11 to 21.92 mg/kg (?C25 hydrocarbons), which may be an indication of rapid migration. The lowest determined MOSH concentrations (?C25 hydrocarbons) were found in sea salt and soda samples, even when their paperboard contained high mineral oil hydrocarbons. Our three samples in packages containing internal bags (for complete barriers) were found to have low mineral oil concentration due to reduced migration through plastic (acrylate-coated polypropylene). However, one sample, a ‘crispy’ product with an internal bag, contained the extreme amount of 21.92 mg/kg. Differences in contaminants observed in both dry foodstuffs and recycled paperboard may have been due to the different packaging and production techniques of the different countries. In addition, 8 of 24 dry foodstuff samples contained MOSH concentrations frequently exceeding the 2.0 mg/kg limit for MOSH C₂₀–C₃₅.     

快餐包装纸中矿物油向固体食品模拟物的迁移

研究从市场上收集到的24 种快餐包装纸中的矿物油向固体食品模拟物Tenax的迁移规律。在多个不同的迁移条件（40 ℃/0.5、1、2、3 h,40 ℃/10 d和70 ℃/2 h）,探究矿物油的迁移行为及其影响因素,以评价其安全性。选择正己烷-乙醇（1∶1,V/V）混合溶液对Tenax进行过夜萃取,采用质量分数0.3%硝酸银固相萃取柱对饱和烃矿物油（mineral oil saturated hydrocarbons,MOSH）和芳香烃矿物油（mineral oil aromatic hydrocarbons,MOAH）进行分离纯化,最后用气相色谱-氢火焰离子化检测法和气相色谱-质谱法分别进行定量和定性分析。结果表明：随着温度的升高,多种快餐包装纸中矿物油向Tenax的迁移量也随之增加。涂蜡纸中MOSH迁移量均有所检出,其数值为110.49～615.40 mg/kg,而MOAH部分均未检出,这可能是因为涂蜡纸表面涂覆的石蜡层属于MOSH类,导致其MOSH部分的迁移量较高。网购餐盘纸和常规餐盘纸中MOSH迁移量约为其特定限量值（0.6 mg/kg）的10～400 倍,MOAH的迁移量约为其特定限量值（0.5 mg/kg）的10～70 倍,而使用优质胶印油墨的原生纤维餐盘纸均未超过其限量值。最后,通过对印有胶印油墨的原生纤维餐盘纸中矿物油进行溯源分析,发现经过迁移的矿物油一部分可能来源于其所用油墨,其他来源可能来自于回收纤维、黏合剂、添加剂和加工助剂等。     

基于液相色谱-气相色谱联用测定巧克力中的饱和烃与芳香烃矿物油

建立基于液相色谱-气相色谱（on-line liquid chromatography-gas chromatography,LC-GC）联用测定巧克力中饱和烃（mineral oil saturated hydrocarbons,MOSH）和芳香烃矿物油（mineral oil aromatic hydrocarbons,MOAH）的方法。该方法以正己烷于60 ℃超声提取20 min,取上清液以硅胶除去脂肪,以间氯过氧苯甲酸与烯烃进行环氧化反应,最后以LC-GC联用技术分离测定,其中LC用于保留油脂和烯烃环氧化物,同时分离得到MOSH和MOAH,通过由阀切换、保留间隙与溶剂排空阀组成的LC-GC接口分别将MOSH和MOAH导入2 个平行的GC通道并以氢火焰离子化检测器测定。该方法的定量限为0.5 mg/kg,矿物油在0.5～85.5 mg/L内线性关系良好（R2=0.998）,加标回收率为80.3%～93.8%,相对标准偏差为1.58%～8.22%。测定了28 个巧克力产品中的矿物油含量,其中有20 个产品检出MOSH,含量为1.83～22.23 mg/kg,1 个检出1.57 mg/kg MOAH。谱图分析表明,一些产品中含有塑料迁移出的聚烯烃低聚饱和烃（polyolefin oligomeric saturated hydrocarbons,POSH）,LC-GC无法分离POSH与MOSH,因此测得结果实际上是MOSH和POSH的总量。     

Potential for short-term migration of mineral oil hydrocarbons from coated and uncoated food contact paper and board into a fatty food simulant

ABSTRACT

Mineral oil hydrocarbons (MOH) are widely used in the food industry for applications such as printing inks, additives, adhesives, and processing aids for food additives. Recently, the migration of MOH from food contact paper and board into foods has raised public health concerns. In this study, a total of 110 food contact paper and board samples, including baking and cooking paper (23), baking cups (28), food packaging bags (22), lunch boxes (8), party plates (26), and straws (3) were evaluated to quantify the content and short-term migration levels of MOH. The MOH were separated into mineral oil saturated hydrocarbons (MOSH)/polyolefin oligomeric saturated hydrocarbons (POSH) and mineral oil aromatic hydrocarbons (MOAH) via a validated on-line liquid chromatography?gas chromatography?flame ionisation detection (LC–GC–FID) technique. The coating materials of the sample products comprised polyethylene, polypropylene, polyethylene terephthalate, and silicone. The effects of the coating materials on the content and migration of MOH/POSH were evaluated. Quantitative analysis of the MOH in the samples showed that the MOSH/POSH and MOAH content varied widely, ranging from 16 to 5626 mg kg^?1 for MOH, regardless of the coating materials. Short-term migration of MOSH/POSH was observed only in samples with polyolefinic coatings, such as polyethylene and polypropylene, in experiments conducted at 25 °C for 10 min, although the extent of MOAH migration for all samples was at the trace level. The migration of MOSH/POSH was detected within the range of 0.93 to 62.3 μg L^?1 in 22 samples, and the migration of MOAH was detected within the range of 0.80 to 2.6 μg L^?1 in only 4 samples. These results demonstrate that although the short-term migration potential of MOH is generally negligible, the migration of MOSH/POSH into wet fatty foods can be accelerated by polyolefinic coatings, even within a very short time.     

Migration kinetics of mineral oil hydrocarbons from recycled paperboard to dry food: monitoring of two real cases

Mineral oil hydrocarbons present in printing inks and recycled paper migrate from paper-based food packaging to foods primarily through the gas phase. Migration from two commercial products packed in recycled paperboard, i.e. muesli and egg pasta, was monitored up to the end of their shelf life (1 year) to study the influence of time, storage conditions, food packaging structure and temperature. Mineral oil saturated and aromatic hydrocarbons (MOSH and MOAH, respectively), and diisopropyl naphthalenes (DIPN) were monitored using online HPLC-GC/FID. Storage conditions were: free standing, shelved, and packed in transport boxes of corrugated board, to represent domestic, supermarket and warehouse storage, respectively. Migration to food whose packs were kept in transport boxes was the highest, especially after prolonged storage, followed by shelved and free-standing packs. Tested temperatures were representative of refrigeration, room temperature, storage in summer months and accelerated migration testing. Migration was strongly influenced by temperature: for egg pasta directly packed in paperboard, around 30 mg kg^?1 of MOSH migrated in 8 months at 20°C, but in only 1week at 40°C. Muesli was contained into an internal polyethylene bag, which firstly adsorbed hydrocarbons and later released them partly towards the food. Differently, the external polypropylene bag, containing pasta and recycled paper tray, strongly limited the migration towards the atmosphere and gave rise to the highest level of food contamination. Tests at increased temperatures not only accelerated migration, but also widened the migration of hydrocarbons to higher molecular masses, highlighting thus a difficult interpretation of data from accelerated simulation.     

Enrichment for reducing the detection limits for the analysis of mineral oil in fatty foods

A German draft for a regulation requires that there must be no migration of mineral oil aromatic hydrocarbons (MOAH) from recycled paperboard into food. The Federal Institute for Risk Assessment (BfR) is requested to establish the detection limit. It was previously shown that the detection limit of the commonly used methods is below 0.1 mg/kg for the majority of the foods, but substantially higher in fatty products because of limited capacity of the liquid chromatographic preseparation to retain fat, interference by olefins and, if also the mineral oil saturated hydrocarbons (MOSH) should be analyzed, the natural paraffins primarily consisting of odd-numbered n-alkanes. A method is described for the enrichment of the MOSH and MOAH conceived as an auxiliary tool for fatty foods analyzed by the conventional methods, such as on-line HPLC–GC. In a double bed liquid chromatographic column, the lower packing consists of a mixture of activated aluminum oxide, silica gel with silver nitrate and activated silica gel, the upper of activated silica gel. The technical detection limit in edible oils is below 0.3 mg/kg, which translates to less than 0.1 mg/kg in the dry foods packed in recycled paperboard. The distinction between migrated mineral oil and that present before packaging often presupposes the availability of the food prior to packaging.     

Migration of mineral oil from printed paperboard into dry foods: survey of the German market. Part II: advancement of migration during storage

In April 2010, 119 samples of dry foods packed in paperboard boxes and stored at ambient temperature were collected from the German market. The migration of mineral oil from the recycled paperboard and printing ink was analyzed for the first time immediately after collection and reported in Vollmer et al. (Eur Food Res Technol 232:175–182, 2011). It frequently exceeded 10–100 times the 0.6 mg/kg limit for mineral oil saturated hydrocarbons (MOSH) derived from the WHO/JECFA evaluation published in 2002. As most samples were far from the end of the shelf life, analyses were repeated 4 months later and a third time either at the expiry date or after 16 months. The average MOSH concentration in the foods increased from 8.9 to 14.3 mg/kg (by 60 %), which indicates a rapid migration during the first months of storage, but also a further increase up to the end of the shelf life. The maximum migration reached 101 mg/kg. In the third measurement, the average concentration of the migrated mineral oil aromatic hydrocarbons was 2.2 mg/kg, with a maximum at 13.2 mg/kg. Most types of food behaved similarly, differences mostly reflecting the types of packaging rather than the food properties. Exceptions were table salt (hardly any migration) and noodles (low migration). Internal bags with an aluminum foil or PET layer were complete barriers. Migration through plastic with vapor-deposited aluminum or acrylate-coated polypropylene was reduced, but still sometimes exceeded 0.6 mg/kg. Internal bags of polyethylene had a weak effect on slowing migration, but acted as a sink for mineral oil: Although on average they only constituted 1.1 % of the total mass of the packs, they absorbed nearly 40 % of the migrating hydrocarbons. Polypropylene was a similar sink. In addition, it strongly slowed migration, but at the third measurement the 0.6 mg/kg limit was nevertheless exceeded in 11 of 16 samples. Polyolefin oligomeric saturated hydrocarbons (POSH) from the plastic or heat-sealable layer, largely branched hydrocarbons similar to MOSH, often migrated in the range of 1–5 mg/kg.     

Determination of mineral oil paraffins in foods by on-line HPLC–GC–FID: lowered detection limit; contamination of sunflower seeds and oils

A method is described to lower the detection limit for mineral oil saturated hydrocarbons (MOSH) in foods as compared to the on-line HPLC–LC–GC–FID method described previously: samples are preseparated (enriched) by conventional liquid chromatography on activated silica gel and activated aluminum oxide. The silica gel retains up to 1 g of fat or oil, the aluminum oxide up to 2 mg n-alkanes of at least 24 carbon atoms, i.e. plant paraffins which may severely hinder the analysis of the mineral paraffins. The efficacy of the method is shown for an apple and sunflower oil. Oils extracted from manually harvested seeds grown in fields or gardens contained between 0.14 and 0.77 mg/kg MOSH. In the oils from seeds sampled in an oil mill, this value was increased to 3.3–9.3 mg/kg, indicating a contamination during harvest, transport and/or storage. Concentrations in commercial refined sunflower oils ranged between 2.7 and 32 mg/kg, averaging 11.2 mg/kg. Since deodorization removes a substantial part of the MOSH, this suggests a further contamination in the oil mill. The contamination affected all samples at a similar level, indicating that it occurs systematically by the presently used technology.     

植物油基鱼罐头中矿物油污染物高灵敏检测方法的建立

本文建立了植物油基鱼罐头中矿物油（MOH）的高灵敏测定方法并调查了部分市售商品的MOH含量。方法采用皂化反应、环氧化反应进行提取和净化，以高效液相色谱-气相色谱联用法（HPLC-GC）分级、富集和定量检测。结果表明:所建立的植物油基鱼罐头中饱和烃矿物油（MOSH）和芳香烃矿物油（MOAH）测定方法的定量限（LOQ）为0.5 mg/kg，加标回收率为90.0%~106.0%，精密度（RSD）为1.6%~12.7%，满足欧洲联合研究中心（JRC）关于高油脂食品中矿物油的分析要求。应用该方法检测了北京地区10个市售鱼罐头产品，发现所有样品均含有MOSH，含量为2.6~53.7 mg/kg，其中5个检出MOAH，含量为0.7~5.5 mg/kg；谱图分析表明这些罐头的MOH污染与其植物油和鱼肉来源密切相关。     

Analysis of mineral oil in food: results of a Belgian market survey

ABSTRACT

Recently, migration of mineral oil components from food contact materials into various foods has been reported. The analysis of mineral oil in food is complicated since it consists of mineral oil saturated hydrocarbons (MOSH) comprising a complex mixture of linear, branched and cyclic compounds and variable amounts of mineral oil aromatic hydrocarbons (MOAH), mainly alkylated. Both MOSH and MOAH form ‘humps’ of unresolved peaks in the chromatograms with the same range of volatility. Since these two fractions have a different toxicological relevance, it is important to quantify them separately. Occurrence data on mineral oil are available only for a limited number of food groups and only from few countries. In Belgium, data on the contamination of food by mineral oil are lacking. In this contribution, an in-house validated online combination of liquid chromatography with gas chromatography (LC–GC) with flame ionisation detection (FID) was used for the quantification of MOSH and MOAH. Totally, 217 packed food samples were selected using a well-defined sampling strategy that targeted food categories which are highly consumed and categories suspected to contain mineral oil. For 19 samples, the method was not applicable. For the 198 remaining samples, MOSH was detected in 142 samples with concentrations up to 84.82 mg kg^?1. For the MOAH fraction, there are 175 samples with a concentration below the limits of quantification (LOQ), while 23 samples had a higher concentration ranging from 0.6 to 2.24 mg kg^?1. Finally, these results were compared with the action thresholds as proposed by the Scientific Committee (SciCom) of the Belgian Food Safety Agency (FAVV-AFSCA). Only one sample exceeded the threshold for MOSH, while the threshold for MOAH was exceeded in 23 samples. For the samples exceeding the action threshold, further investigation is needed to identify the contamination source.     

Concentrations of migrated mineral oil/polyolefin oligomeric saturated hydrocarbons (MOSH/POSH) in Chinese commercial milk powder products

ABSTRACT

Mineral oil contaminants migrated from food contact materials have raised much concern in the past few decades. However, survey data of the occurrence of mineral oils in foods are only available for a limited variety of foods, which do not include the contaminants in Chinese milk powders. Thus, to conduct an analysis of mineral oils migrated into milk powder products from different packaging materials, 50 Chinese commercial samples (including 38 infant formulas), which were packaged in metal cans, paper containers, paper boxes and aluminium foil-plastic bags, were analysed. Mineral oil saturated hydrocarbons (MOSH), polyolefin oligomeric saturated hydrocarbons (POSH) and aromatic hydrocarbons (MOAH) migrated into those samples were extracted and quantitatively analysed by on-line liquid chromatography coupled with gas chromatography (LC-GC). The results indicated no surface MOAH was detected in any of the samples, while 33 samples contained MOSH/POSH with surface contents of 0.10 ~ 5.09 mg kg^?1. Moreover, the amounts of those MOSH/POSH are closely related to packaging materials, among which the surface contamination values of products in metal cans were the lowest, followed by products in paper containers and boxes, and the values of samples in aluminium foil-plastic bags were the highest. In addition, the surface MOSH/POSH content exhibited a positive correlation with fat content in the samples due to their similar polarities.     

Comparability of mineral oil testing for dry food and cardboard samples – Perspectives from different PT rounds

Mineral oil hydrocarbons (MOH) can be found in detectable levels in a multitude of foodstuffs. Therefore, chemical analysis of food for MOH gains importance. Different proficiency testing (PT) rounds on mineral oil testing have been performed in different matrices: cereals and rice as well as cardboard samples were examined. The laboratories participating in the PT rounds had to follow specific requirements for examination. The sample materials used contained different concentrations of mineral oil saturated hydrocarbons (MOSH) and mineral oil aromatic hydrocarbons (MOAH). The PT results were statistically evaluated according to ISO 13528:2005 and additionally the HorRat(R) value was calculated to gain information on the comparability of the mineral oil testing. It could be shown that for the examined sample materials and under the chosen specifications for testing a comparable determination of the mineral oil content is possible within the required relative standard deviations. A useful analytical determination can be achieved with an acceptable relative standard deviation of <50% from a concentration of defined mineral oil fractions at ≥1 mg/kg in food. In the concentration range for MOH in food of between 1 mg/kg and 2 mg/kg, relative standard deviations of 20–40% were achieved. MOH concentrations of ≥ 2 mg/kg food were determined with good relative standard deviations of around 20%. Moreover, due to the results gained within this work a statement concerning the comparability for MOSH and MOAH contents below concentrations of 1 mg/kg food is possible: under the chosen conditions for examination as part of this work, mineral oil determination below 1 mg/kg food showed high variability. To gain reliable information with regard to consumer protection on the risk of mineral oil contents in this low concentration range further standardisation of the test method is indicated.     

纸质食品包装材料的矿物油迁移研究进展

食品中的矿物油污染物是指石油来源的C10~C50烃类化合物, 包括烷烃矿物油(mineral oil saturated hydrocarbons, MOSH)和芳烃矿物油(mineral oil aromatic hydrocarbons, MOAH)2大类。近年来的研究表明, 食品中的矿物油污染物主要来源于食品的回收纸包装材料迁移。本文综述了国外近十年来纸质包装材料的矿物油迁移研究情况, 包括纸质包装材料迁移的矿物油分析方法——液相色谱-气相色谱联用法; 矿物油迁移至食品的2种方式: 气态扩散迁移和包装材料接触迁移; 降低矿物油迁移的技术方法, 即食品包装纸质材料的回收工艺, 向包装纸质中添加活性炭等吸附剂以及增加阻隔层以阻挡矿物油的迁移。旨在为相关企业和机构提供数据与技术参考。     

Saturated and aromatic mineral oil hydrocarbons from paperboard food packaging: estimation of long-term migration from contents in the paperboard and data on boxes from the market

In the absence of a functional barrier, mineral oil hydrocarbons from printing inks and recycled fibres tend to migrate from paper-based food-packaging materials through the gas phase into dry food. Concentrations easily far exceed the limit derived from the acceptable daily intake (ADI) of the Joint FAO/WHO Expert Committee on Food Additives (JECFA). Since the estimation of long-term migration into the food by testing at 40°C for 10 days is difficult, it seems preferable (and easier) to use the mineral oil content in the paperboard. Evaporation experiments showed that hydrocarbons eluted up to about n-C?? are sufficiently volatile for relevant migration into dry food: in worst-case situations, about 80% migrate into the packed food. The extraction of the paperboard was optimised to give good recovery of the relevant hydrocarbons, but to discriminate against those of high molecular mass which tend to disturb gas chromatographic analysis in on-line coupled normal phase HPLC-GC-FID. Even though some of the relevant hydrocarbons had already evaporated, the average concentration of < C?? mineral oil saturated hydrocarbons (MOSH) in the paperboard boxes of 102 products from the Swiss and Italian market was 626 mg kg?1. Nearly 15% of investigated boxes still contained more than 1000 mg kg?1 < C?? MOSH up to over 3000 mg kg?1 (maximum = 3500 mg kg?1). This amount of MOSH in the board have the potential of contaminating the packed food at a level exceeding the limit, derived from the JECFA ADI, hundreds of times.     

食品接触材料中烃类矿物油毒性和风险管理

烃类矿物油(mineral oil hydrocarbons,MOHs)是一类由多种烃类物质组成的复杂混合物。现阶段,针对烃类矿物油毒理学数据比较缺乏,毒理学动物试验数据能否外推至人体仍存在争议。对饱和烃矿物油(MOSH)的毒性主要关注其生物蓄积性,C_(16)～C_(35)的MOSH能在人体和大鼠组织中蓄积并可形成微肉芽肿;而含有3～7个芳香环的芳香烃矿物油(MOAH)具有致突变和致癌性,以及是潜在的内分泌干扰物。欧洲食品安全局指出人群暴露于烃类矿物油的健康风险值得关注。食品接触材料是食品中烃类矿物油污染的重要来源,而由回收纸纤维制作的食品接触纸制品中烃类矿物油污染食品的问题尤为突出。为完善对烃类矿物油的风险管理,应基于化学成分而不是粘度指标,对特定组分烃类矿物油开展毒理学研究和膳食暴露评估。     

食品中矿物油分析方法的考察验证与结果确证

矿物油是指来源于石油和合成油的C10~C50烷烃(MOSH)和芳烃(MOAH)类物质的总称,其化合物类型众多且数量巨大;食品的种类多样且基质干扰严重,其中涉及矿物油的干扰物有油脂、天然烷烃、固有烯烃以及包装材料迁移至食品的寡聚烯烃饱和烃(POSH)等。因此,分析食品中的矿物油相当困难。通常,矿物油分析步骤包括提取、净化分离和测定三个环节。为了保证检测方法的可靠性,样品中必须添加9个标准化合物(包括3个分离标记物,2个挥发损失标记物和2对定量内标物),用于监测矿物油的净化、分离与测定效果;同时需要经常插入空白实验和正构烷烃混合标准用于考察操作规范、试剂纯度、仪器性能等。由于矿物油来源与食品基质干扰物的复杂性,实际分析中还需要给出每类样品的定量限和回收率等方法学考察数据,以证明矿物油分析方法的灵敏度和准确度。对于部分基质干扰严重的样品,还需要采用全二维气相色谱-飞行时间质谱进行分析结果的确认。本文结合食用油、奶粉、巧克力和大米等分析实例,综述了食品中矿物油测定的验证与确认方法。     

Is recycled newspaper suitable for food contact materials? Technical grade mineral oils from printing inks

Recycled paper and board used in food packaging materials (boxes, paper bags) often cause migration of mineral oil into food at levels which are unacceptable according to present toxicological assessments. When foods in recycled board are densely packed into larger boxes or onto pallets, most of the hydrocarbons up to n-C₂₀ may migrate into the packed food within a few weeks, those up to n-C₂₈ at a decreasing rate. Unprinted recycled board contained 300–1,000 mg/kg mineral oil <n-C₂₈. The main sources are the inks used for printing newspapers: newspapers contained roughly 3,000 mg/kg mineral oil <n-C₂₈. These mineral oils fall into classes for which JECFA established a tolerable daily intake of 0.01 mg/kg body weight. Using standard assumptions for calculating specific migration limits, a maximum tolerable concentration in food of 0.6 mg/kg is derived. This evaluation assumes highly refined white oils, whereas the oils found in recycled board are of technical quality and contain 15–25% aromatic compounds, predominantly with 1–3 aromatic rings, as shown by comprehensive GC × GC. This finding precipitates authorities into a dilemma: recycling is supported for the sustainable use of materials, but on the basis of present toxicological assessments the migration is often far beyond acceptable.     

Saturated and aromatic mineral oil hydrocarbons from paperboard food packaging: estimation of long-term migration from contents in the paperboard and data on boxes from the market

In the absence of a functional barrier, mineral oil hydrocarbons from printing inks and recycled fibres tend to migrate from paper-based food-packaging materials through the gas phase into dry food. Concentrations easily far exceed the limit derived from the acceptable daily intake (ADI) of the Joint FAO/WHO Expert Committee on Food Additives (JECFA). Since the estimation of long-term migration into the food by testing at 40°C for 10 days is difficult, it seems preferable (and easier) to use the mineral oil content in the paperboard. Evaporation experiments showed that hydrocarbons eluted up to about n-C₂₄ are sufficiently volatile for relevant migration into dry food: in worst-case situations, about 80% migrate into the packed food. The extraction of the paperboard was optimised to give good recovery of the relevant hydrocarbons, but to discriminate against those of high molecular mass which tend to disturb gas chromatographic analysis in on-line coupled normal phase HPLC-GC-FID. Even though some of the relevant hydrocarbons had already evaporated, the average concentration of?<?C₂₄ mineral oil saturated hydrocarbons (MOSH) in the paperboard boxes of 102 products from the Swiss and Italian market was 626?mg?kg^?1. Nearly 15% of investigated boxes still contained more than 1000?mg?kg^?1?<?C₂₄ MOSH up to over 3000?mg?kg^?1 (maximum?=?3500?mg?kg^?1). This amount of MOSH in the board have the potential of contaminating the packed food at a level exceeding the limit, derived from the JECFA ADI, hundreds of times.     

餐盘纸中矿物油的检测及溯源分析

对15 种餐盘纸中矿物油的含量进行检测，并对其中1 种印刷有已知油墨的餐盘纸进行溯源分析。采用离线固相萃取前处理，以混合溶液（正己烷-乙醇（1∶1，V/V））作为提取溶剂，经0.3%硝酸银硅胶固相萃取柱分离纯化，气相色谱-氢火焰离子化检测法进行定量，气相色谱-质谱法进行定性分析。结果表明：网店购买的4 种餐盘纸的矿物油含量普遍比快餐店中收集到的餐盘纸高，饱和烃矿物油的最高含量为3 397.6 mg/kg，芳香烃矿物油的最高含量为374.6 mg/kg，均超过限量值。通过溯源分析发现，有印刷的餐盘纸中一部分矿物油来源于油墨。本方法的检出限和定量限分别为2.73 mg/kg和8.19 mg/kg，加标回收率为92.1%～115.1%，相对标准偏差为3.12%～11.85%，准确性高，实验操作方便，可用于食品接触用纸中矿物油的检测及溯源分析。     

Mineral oil in sunflower seeds: the sources

All sunflower oils previously analyzed were found to be somewhat contaminated with mineral oil. Now sunflower seeds harvested manually or mechanically, sampled from the field to the drying at the collection centers, were analyzed in order to determine the sources. The composition of the mineral oil saturated hydrocarbons in the hand-picked seeds suggested the presence of mainly lubricating oil from the atmosphere. Referring to the oil in the seeds, concentrations ranged from 0.1 mg/kg in a rural area of Switzerland to 2.4 mg/kg near the town of Zürich. Harvesters contaminated the seeds with up to 7 mg diesel oil/kg oil and up to 11 mg/kg lubricating oil. The drying in one of the collection centers added 30–40 mg/kg fuel oil. It is surprising how little attention is paid to food contamination by mineral oil products despite concentrations widely exceeding the acceptable daily intake specified by the WHO/JECFA.