气相色谱-质谱法测定聚氯乙烯包装材料和食品模拟物中的46种增塑剂

建立了46种增塑剂在聚氯乙烯(PVC)食品包装材料中的含量及其在水、3%乙酸、10%乙醇和橄榄油4种食品模拟物中迁移量的气相色谱-质谱(GC-MS)测定方法。食品包装材料、水质模拟物和橄榄油中增塑剂分别采用溶解-沉淀法、正己烷液-液萃取和凝胶渗透色谱(GPC)法提取。采用GC-MS法,在选择离子监测模式(SIM)下对46种增塑剂进行定性,采用外标法进行定量测定。各种增塑剂在0.1～2.0 mg/L质量浓度范围内呈线性,相关系数为0.9910～0.9999,各组分检出限均在0.005～0.05 mg/kg之间。在2种食品模拟物中,3个浓度添加水平下46种增塑剂的加标回收率在69.51%～107.21%之间,精密度(RSD, n=6)为3.53%～18.95%。该方法可满足PVC食品接触制品及4种不同性质的食品模拟物中多种类增塑剂的快速筛查和准确定性、定量测定要求。     

Migration of non intentionally added substances from adhesives by UPLC–Q‐TOF/MS and the role of EVOH to avoid migration in multilayer packaging materials

Polyurethane adhesives are commonly used to laminate multilayer packaging materials for food. Since these materials are in direct contact with the food, compounds could migrate from adhesive into it. For this reason, it is important to identify all the potential migrants and verify their migration. Ultra‐high performance liquid chromatography–quadrupole time‐of‐flight–mass spectrometry analyses and ChemSpider database are used to identify the potential migrants from polyurethane adhesives, and these techniques were demonstrated to be very powerful and useful tools for this purpose. Migration tests were carried out using Tenax® as food simulant. Nine out of fifteen non‐volatile compounds, identified in the cured adhesives, migrated. Most of them were identified as cyclic compounds, adipic based, which is the most commonly used monomer to make the polyester/polyol resins for polyurethane bi‐component adhesives. In this work, the use of EvOH layer in several multilayer materials to minimize or avoid migration was evaluated too. Copyright © 2013 John Wiley & Sons, Ltd.     

The validation of a method for determining the migration of trace elements from food packaging materials into food

A new radiotracer method has been developed to measure the migration of trace elements from food contact packaging into four standard food simulants; acetic acid, ethanol, olive oil, deionised water. A sample of material is irradiated in a thermal neutron flux of 10¹⁶n·m^–2·s^–1 to activate the trace elements and produce a range of radionuclides. The sample is then placed in the food simulant and the migration of the radionuclides is monitored by performing -ray spectrometry on a sample of the simulant. Any radionuclides measured must be due entirely to the migration of the elements present in the plastic, since the simulant itself is not radioactive. Preliminary studies have shown that detection limits of around 0.2g·dm^–2 (0.002 mg/kg) can be achieved for antimony in a sample of polyethylene terephthalate. This method can now been extended to measure migration into real foods. This will highlight any differences between the standard simulants currently used and real foods. Since the method only involves irradiation of the packaging material, any food matrix can be studied.     

Aromatic amines from polyurethane adhesives in food packaging: The challenge of identification and pattern recognition using Quadrupole-Time of Flight-Mass Spectrometry

Toxic primary aromatic amines (PAAs) are reaction products from residual isocyanates in polyurethane adhesives. The maximum migration level of the total sum of PAAs is 10 ng g⁻¹ of food. This paper reports on a method for quantification of 18 PAAs by UHPLC–MS/MS that was optimised and applied to a series of industrial laminates prepared from polyurethane adhesives. Non-intentionally added substances (NIAS), impurities and other migrants were identified by Q-TOF/MS^E. A comparison of the quantitative values obtained by the colorimetric method using NEDA and by UHPLC–MS/MS confirmed that the first method can overestimate the quantification of PAAs. This could be attributed to the impurities and other NIAS present in the plastic laminate. Values of R² in the analytical characteristics of UHPLC–MS/MS were obtained, the best value being 0.9964 and the most unfavourable 0.7626. The detection limit (LOD) and the quantification limit (LOQ) were 2 pg g⁻¹ and 7 pg g⁻¹, respectively. The stability of the PAAs over time in the acidic simulant in contact with the plastic laminate is also reported.     

MALDI-MS and colorimetric analysis of diisocyanate and polyol migrants from model polyurethane adhesives used in food packaging

The identification of the migrants, into food simulants, from a series of polyurethane adhesives used in the manufacture of plastic film laminates for use in common food packaging is described. Commercial materials, based on four different model adhesive systems, were prepared by an industrial collaborator. The MALDI-MS fingerprint patterns of the three polyether and one polyester polyol components of these adhesives were obtained for reference purposes. The decrease in the level of diisocyanate as a migrant versus time after lamination was confirmed by colorimetric measurements. The migration of the standard polyol samples through polyethylene pouches into water at 70 degrees C has been demonstrated and also the attenuation effect for different polyols. Cured laminates in the form of pouches were used to carry out the migration experiments into distilled water, inside the pouch, at 70 degrees C over a period of 2 h. Comparison of the migration results from the food packaging laminates with those from the polyethylene film confirmed the migration of unreacted polyol components for the polyether-based systems. Cyclic oligomers from the polyol starting materials were identified as the migrants from the polyester-based adhesive.     

食品包装材料中7种光引发剂向水性模拟液中的迁移测定

为了考察食品包装材料中光引发剂向食品中迁移的情况,以水性模拟液作为迁移溶剂,用65 μm聚二甲基硅氧烷/二乙烯基苯(PDMS-DVB)纤维头进行固相微萃取结合气相色谱-质谱(SPME/GC-MS)分析方法同时测定食品包装材料中7种光引发剂(PIs)的迁移量。方法的检出限为0.0012～0.0069 μg/L,线性范围为0.03～1.0 μg/L (r2＞0.9909),在3种浓度的添加水平下,加标回收率为70.8%～112.0%,相对标准偏差不大于14.0%。利用建立的方法对20个实际样品进行测定,发现所有样品中均检出二苯甲酮,其中10个样品中检出4-甲基二苯甲酮,3个样品中检出1-羟基环己基苯基甲酮,1个样品中检出安息香双甲醚。该方法的灵敏度高,样品前处理过程简单,无需使用有机溶剂,为食品接触材料表面印刷油墨中PIs向水性样品中的迁移测定提供了参考。     

Identification of non-volatile compounds and their migration from hot melt adhesives used in food packaging materials characterized by ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry

The identification of unknown non-volatile migrant compounds from adhesives used in food contact materials is a very challenging task because of the number of possible compounds involved, given that adhesives are complex mixtures of chemicals. The use of ultra-performance liquid chromatography coupled to quadrupole time-of-flight mass spectrometry (UPLC-MS/QTOF) is shown to be a successful tool for identifying non-targeted migrant compounds from two hot melt adhesives used in food packaging laminates. Out of the seven migrants identified and quantified, five were amides and one was a compound classified in Class II of the Cramer toxicity. None of the migration values exceeded the recommended Cramer exposure values.     

Effect of gamma irradiation on caprolactam migration from multilayer polyamide 6 films into food simulants: development and validation of a gas chromatographic method

A GC method to determine caprolactam in water, 15% ethanol, and olive oil food simulants was developed and validated. Linear ranges varied from 0.96 to 642.82 microg/mL for water, 0.64 to 800.32 microg/mL for 15% ethanol, and 1.06 to 1062.34 microg/g for olive oil, with correlation coefficients higher than 0.999. Method precision studies showed RSD values lower than 5.45%, while method accuracy studies showed recovery from 72 to 111% for all simulants. The effect of gamma irradiation on caprolactam migration from multilayer polyamide 6 (PA-6) films intended for cheese into water, 15% ethanol, olive oil, and 3% acetic acid simulants was also studied. For migration assay, non-irradiated and irradiated (12 kGy) films were placed in contact with the simulant and exposed at 40 degrees C for 10 days. The validated method was used to quantify caprolactam migration from multilayer PA-6 films into the simulants, which ranged from 1.03 to 7.59 mg/kg for non-irradiated films, and from 4.82 to 11.32 mg/kg for irradiated films. Irradiation caused almost no changes in caprolactam levels, with the exception of olive oil, which showed an increase in the caprolactam level. All multilayer PA-6 films were in accordance with the requirements of the legislation for caprolactam migration.     

Analytical procedure for the determination of Ethyl Lauroyl Arginate (LAE) to assess the kinetics and specific migration from a new antimicrobial active food packaging

Ethyl Lauroyl Arginate (LAE) is a cationic tensoactive compound, soluble in water, with a wide activity spectrum against moulds and bacteria. LAE has been incorporated as antimicrobial agent into packaging materials for food contact and these materials require to comply with the specific migration criteria. In this paper, one analytical procedure has been developed and optimized for the analysis of LAE in food simulants after the migrations tests. It consists of the formation of an ionic pair between LAE and the inorganic complex Co(SCN)₄²⁻ in aqueous solution, followed by a liquid–liquid extraction in a suitable organic solvent and further UV–Vis absorbance measurement. In order to evaluate possible interferences, the ionic pair has been also analyzed by high performance liquid chromatography with UV–Vis detection. Both procedures provided similar analytical characteristics, with linear ranges from 1.10 to 25.00 mg kg⁻¹, linearity higher than 0.9886, limits of detection and quantification of 0.33 and 1.10 mg kg⁻¹, respectively, accuracy better than 1% as relative error and precision better than 3.6% expressed as RSD. Optimization of analytical techniques, thermal and chemical stability of LAE, as well as migration kinetics of LAE from experimental active packaging are reported and discussed.     

A radiotracer technique for the migration of inorganic contaminants into dry food from packaging made from recycled paper and board

Summary In nuclear and radiochemistry the concepts of specific activity, radioactive concentration, isotopic and non-isotopic carrier, carrier-free and no-carrier-added are of paramount relevance. In fact, traces of carrier are easily introduced in the radioactive preparations by their presence in the target material, by equipment and chemicals used in target processing, and may also be produced by side nuclear reactions induced in the target by nuclear activation, sometimes followed by a decay chain. Very sensitive analytical and radioanalytical techniques allow the determination of the real value of specific activity of no-carrier-added radionuclides and labeled compounds. Thus, in this paper we show with several examples that in most practical cases the term carrier-free (CF) is used improperly and has to be substituted by the more suitable term no-carrier-added (NCA). Carrier-free radionuclides and labeled compounds do exist in a few selected cases only.     

Analytical method for the simultaneous determination of polyfunctional amines used as monomers in the manufacture of food packaging materials

This paper describes the development of a multi-analyte method for the determination of polyfunctional amines commonly used as monomers in the manufacture of food contact materials. Amines were analyzed by high-performance-liquid chromatography with diode-array detection (HPLC-DAD) after derivatization with dansyl chloride. The chromatographic analysis and the derivatization conditions were optimized. The proposed method was validated in terms of linearity, limits of detection and repeatabilities. The method showed an excellent sensitivity (LOD≤0.05 μg/mL) and appropriate repeatabilites (RSD (n=7)≤5%)). LC-MS/MS was used as a confirmatory technique. The stability of the amines in five food simulants (distilled water, 3% acetic acid, 10% ethanol, 50% ethanol and olive oil) under the most common testing conditions (10 days at 40 °C) was also studied. Results showed that amines had an acceptable stability in aqueous simulants but in the olive oil a loss of 100% was observed for all analytes.     

Determination of paraffins in food simulants and packaging materials by liquid chromatography with evaporative mass detection and identification of paraffin type by liquid chromatography/gas chromatography and fourier transform infrared spectroscopy

A liquid chromatographic method with evaporative mass detection (EMD) is described for the determination of paraffins in food contact materials that do not contain polyolefin oligomers, or paraffins migrating from these materials into fatty food simulants or certain simple foods. A normal-phase column operating at maximum column efficiency separates nonparaffinic and paraffinic materials without resolving the latter into individual components, and EMD is used to quantitate the paraffins. An on-line qualitative method that uses liquid chromatography/gas chromatography with flame ionization detection discriminates between paraffin waxes and oils in food contact materials, food simulants, and certain simple foods; a Fourier transform infrared spectrophotometric qualitative method also discriminates between waxes and oils, but is usually restricted to food contact materials that do not contain polyolefins and to migration experiments with organic solvents as fatty food simulants (with some other fatty food simulants, paraffin type must then be identified in the food contact material).     

Liquid chromatography with tandem mass spectrometry method for trace level analysis of migrated secondary alkanesulfonate from poly(tetramethylene terephthalate) into food simulants

Secondary alkanesulfonate has been widely used as an antistatic additive in polymers for producing anti‐dust food packaging containers. Currently, no reported method exists for accurate quantification of secondary alkanesulfonate in ethanolic and acidic food simulants. A new liquid chromatography with tandem mass spectrometry method was developed to quantify the migrated amount of secondary alkanesulfonate at trace levels in food simulants from a poly(tetramethylene terephthalate) containing secondary alkanesulfonate. The poly(tetramethylene terephthalate) samples loaded with the antistatic additive were exposed to various food simulants. The collected extracts were directly analyzed by liquid chromatography with tandem mass spectrometry in electrospray ionization negative mode. As secondary alkanesulfonate is a mixture containing C14 to C17 chain lengths, it was separated on a Poroshell 120 EC‐C8 column adopting methanol water gradient program. The migration of secondary alkanesulfonate ranged from 58 to 329 ppb; which is well within the allowed permissible regulatory limits and the adopted method was validated by conducting spiking studies and acceptable recoveries were obtained. The developed method was not only sensitive to detect lower levels of the migrated antistatic additive, but it also avoided more cumbersome sample preparation methodologies like sample enrichment and other derivatization approaches.     

高效液相色谱-串联质谱法测定食品包装材料中全氟辛烷磺酰基化合物(PFOS)

建立了用高效液相色谱-串联质谱(HPLC/MS/MS)结合快速溶剂萃取测定食品包装材料中全氟辛烷磺酰基化合物(PFOS)的方法。采用乙腈溶剂,快速溶剂提取食品包装材料中的PFOS,提取液经0.2μm有机滤膜过滤后,以V(乙腈)∶V(10 mmol/L乙酸铵溶液)=80∶20为流动相,经HPLC分离后用多级反应监测(MRM)方式测定。用两个子离子的相对丰度定性,外标法定量。PFOS在0.002~0.1μg/mL范围内线性良好(R2=0.998),回收率为93.8%~101%,精密度RSD为1.6%~3.1%,方法检出限为0.4μg/m2(S/N≥10),满足欧盟法规对食品包装材料中PFOS的限量检测要求。方法可用于食品包装材料中PFOS的检测。     

Studies on the stabilization of poly(vinyl chloride) with epoxides. Transformation products and their migration from packaging to foods

Epoxidized glyceryl trioleate has been used as a model compound to extend previous studies on the mode of action of epoxides in the stabilization of poly(vinyl chloride) (PVC). Sheets of PVC containing 3% expoxidized glyceryl tri[1-¹⁴C]oleate were prepared on a hydraulic press and subsequently heated in an oven for various times to simulate heat processing. After separation of the polymer from the low molecular weight components by steric exclusion chromatography, there was only a negligible amount (max. 2%) of bonding to the polymer and progressive loss from 15 to 90% of epoxide function occurred with heat processing over the period from 0.2 to 40 min. The concentration of the chlorohydrin transformation product was estimated by high performance steric exclusion chromatography after formation of a suitable u.v. detectable derivative, but the levels found did not fully account for the overall loss of epoxide. To assess the potential of both epoxide and chlorohydrin for migration from plastic packaging into foods, sheets individually containing the epoxide and the corresponding chlorohydrin were placed in contact with a range of solvents, orange squash and edible oil. No migration was measurable at a limit of detection of 0.1 ppm (orange squash limit 0.5 ppm) after 10 days contact at 40, with the exception of edible oil where a level of 1.0 ppm was detectable.     

常见食品中邻苯二甲酸酯类增塑剂含量及食品包装材料中邻苯二甲酸酯类增塑剂迁移量的测定

采用气相色谱-质谱联用(GC-MS)方法并结合液液萃取及基质分散固相萃取的样品处理方式,建立了测定饮料、牛奶、白酒3类食品中16种邻苯二甲酸酯类增塑剂的分析方法。研究结果表明16种邻苯二甲酸酯类增塑剂的检出限(LOD, S/N=3)范围为0.005~0.025 mg/L;峰面积的相对标准偏差(RSD)均小于2%。饮料、牛奶、白酒3种样品的加标回收率范围普遍在60%~110%。所建方法简便、灵敏、准确,可满足饮料、牛奶和白酒中痕量邻苯二甲酸酯类增塑剂的测定需要。此外,将该方法应用于食品包装材料中邻苯二甲酸酯类增塑剂的迁移研究,以异辛烷为油脂食品模拟物,测定了保鲜膜与保鲜袋中16种邻苯二甲酸酯类增塑剂的迁移量。结果显示保鲜膜存在显著的邻苯二甲酸酯类增塑剂迁移现象。     

高效液相色谱-紫外检测法同时测定食品接触材料中7种苯多酸及其衍生物的特定总迁移量

建立了高效液相色谱-紫外检测(HPLC-UV)同时测定5种食品模拟物(10%(v/v)乙醇、20%(v/v)乙醇、50%(v/v)乙醇、3%(w/v)乙酸和橄榄油)中偏苯三甲酸、偏苯三甲酸酐、间苯二甲酰氯、间苯二甲酸、对苯二甲酰氯、邻苯二甲酸、对苯二甲酸的特定总迁移量(SML(T))的方法。用食品模拟物浸泡待测样品,冷却至室温并混匀,水基食品模拟物经亲水性聚四氟乙酸针头过滤器过滤后进样;橄榄油用0.1%(w/v)乙酸铵水溶液提取后,下层清液用亲水性聚四氟乙烯针头过滤器过滤后进样。用Synergi Polar-RP色谱柱(250 mm×4.6 mm, 4 μm)分离,梯度洗脱,检测波长为232 nm。5种食品模拟物中的定量限为0.1~0.2 mg/kg;水基食品模拟物在0.5~12 mg/L、橄榄油食品模拟物在0.5~12 mg/kg范围内线性关系良好(r² > 0.99991); 1.25、2.5、6.25 mg/kg水平的加标回收率为94.3%~105%,相对标准偏差为0.1%~2.3%。结果表明,该方法的色谱分离和线性关系较好,回收率和准确度高,完全满足欧盟(EU)No 10/2011法规附表2中7种苯多酸及其衍生物的SML(T)的限量要求,并已应用于实际样品的检测。