Delamination of multilayer packaging caused by exfoliating cream ingredients

Exfoliating creams were packed in sachets of composite packaging consisting of polyethylene, aluminium and polyester layers stuck together by polyurethane adhesive, and they were kept in an oven at 40°C in order to accelerate the delamination process. The sachets were then delaminated and the resulting layers were analysed. A headspace solid‐phase microextraction mass spectrometry method (HS–SPME–GC–MS) using a 75µm carboxen polydimethylsiloxane fibre was used to identify the compounds migrating from the exfoliating creams through the polyethylene layer to the aluminium interface and suspected to be responsible for packaging delamination. Several volatile compounds used in the cosmetic industry as perfumes, fixing agents and preservatives, such as menthol, dihydromyrcenol and 2‐phenoxyethanol, were detected in the aluminium/polyester delaminated layer. The exfoliating creams were also analysed by HS–SPME–GC–MS. The study of loss of adhesion of the laminated material exposed to the exfoliating products revealed that the product with a higher concentration of 2‐phenoxyethanol caused a faster decrease in adhesion strength, but the lower adhesion values were found in products with higher concentrations of menthol and dihydromyrcenol. The results obtained showed that the analytical method used was suitable for identifying volatile compounds that migrate through polyethylene to the inner layers of the packaging of exfoliating products, as well as for providing prior information on which products may be difficult to package in sachets. Copyright © 2006 John Wiley & Sons, Ltd.     

基于HS-SPME-GC-MS与电子舌分析冷藏冠玉枇杷的风味特性

目的 探讨冷藏对枇杷果实风味品质的影响。方法 采用顶空固相微萃取-气相色谱质谱联用(HS-SPME/GC-MS)、液相色谱和电子舌检测技术,研究冠玉枇杷在温度为(6±0.5)℃,相对湿度为90%~95%的环境下果实的滋味特性、酸度、糖组分含量及挥发性物质的变化情况。结果 电子舌检测结果表明,在贮藏过程中枇杷的酸味下降明显,贮藏14 d后味觉指标发生显著变化,主成分1的方差贡献率达到85.17%,酸味、甜味与可溶性固形物、pH值呈高度相关性,与可溶性糖缺乏关联性。蔗糖含量在冷藏过程中表现为持续下降趋势,质量损失率为56.7%。HS-SPME/GC-MS结果表明,在枇杷果实中共检测出37种挥发性物质,其中醛类化合物为枇杷的主要挥发性成分,相对含量接近40%。挥发性物质的种类和含量随着贮藏时间会发生变化,己醛的相对含量会降低,(E)-2-己醛含量显著增加。结论 在冷藏过程中,冠玉枇杷果实的酸味明显下降,蔗糖含量显著减少,主要香气成分己醛和(E)-2-己醛可以作为枇杷采后贮藏品质评价的重要指标,并且在贮藏14~21 d期间是风味变化较为明显的阶段。     

Determination of ϵ‐caprolactam migration from polyamide plastics: a new approach

A new gas chromatography method for determination of ?‐caprolactam (CPR) migration from packaging materials such as: polyamide (PA) films, PA granulates, PA/PE (polyethylene) laminates, PA casings, etc., to food simulants has been developed. Water, 3% w/v acetic acid, 15% and 95% v/v ethanol and olive oil have been used as a food simulants. Using the 1,4‐butanediol (BUG) as an internal standard (instead of aza‐2‐cyclononanone), calibration curves were constructed. Very good separation of CPR from BUG was achieved by using a Nukol fused silica capillary column (Supelco), 25 m × 0.32 mm. The time of analysis is shorter than 12 min: 7.69 min for BUG and 11.60 min for CPR. The regression line equation for CPR migration to water is: y = 0.080x + 0.14; to olive oil: y = 0.010x. The sensitivity of the developed method is appropriate for the quantitative determination of CPR in an analyte concentration of approximately 0.2 mg/kg, when the specific migration limit (SML) for this compound, according to Directive 90/128/EEC, is 15 mg/kg food simulant. Copyright © 2001 John Wiley & Sons, Ltd.     

Determination of Four Types of Hazardous Chemicals in Food Contact Materials by UHPLC‐MS/MS

A simple ultrahigh‐performance liquid chromatography (UHPLC) tandem mass spectrometric method for the identification and quantification of two photoinitiators 4‐methylbenzophenone and 2‐ethylhexyl‐4‐dimethylaminobenzoate; nine plasticizers including di(2‐ethylhexyl) adipate and diisobutyl adipate; three primary aromatic amines 4‐aminobiphenyl, 4‐amino‐2′,3‐dimethylazobenzene and bis‐(4‐aminophenyl) methane and six bisphenols bisphenol F diglycidyl ether, bisphenol A diglycidyl ether, bisphenol A (BPA), bisphenol B (BPB), bisphenol E (BPE) and bisphenol F (BPF) in food contact materials has been developed. The chromatographic conditions, pre‐treatment methods and matrix effects were studied and optimized. For the determination of the four bisphenols, BPA, BPB, BPE and BPF, the UHPLC method employed a mobile phase of aqueous ammonia and methanol in binary gradient mode, and measurement was based on a triple quadrupole mass spectrometer equipped with an electrospray ionization (ESI) source operating in negative ion mode. The remaining chemicals were determined using the ESI source in positive ion mode and using the [M + NH₄]⁺ or [M + H]⁺ adducts as precursor ions for tandem mass spectrometry. The calibration graphs were linear with correlation coefficients of above 0.995. Detection limits for the method were in the range of 1–16 µg/kg. Analyte recovery values were in the range of 70–114%, and relative standard deviations were 1–14%. Under optimized conditions, the chromatographic separation was performed in 12 min. The validation data indicated that the method was effective for the determination of the four classes of hazardous chemicals in plastic packaging materials or in can lacquers. The optimized method was successfully applied to trace analysis of commercially available food contact materials. Copyright © 2014 John Wiley & Sons, Ltd.