Polypropylene: establishment of a rapid extraction test for overall migration limit compliance testing

In order to demonstrate compliance with the overall migration limit given in EC Directive 90/128/EEC, overall migration tests are usually performed on the finished food packaging with food simulants. As a consequence, the packaging industry is confronted by a significant compliance testing burden to demonstrate that their products are suitable for food use applications. However, the Directive also allows compliance with migration limits to be demonstrated by use of a ‘more severe test’. In this study a ‘more severe test’ has been developed for polypropylene materials and articles involving extraction with the solvent, diethyl ether. The solvent was removed from the samples, evaporated to dryness and the mass of the non‐volatile residue determined. This extracted residue represents the overall migration value. This procedure has been optimized so that it is simple and rapid to perform and, in general, gives slightly higher results compared to overall migration tests conducted with fatty and aqueous food simulants. Copyright © 2000 John Wiley & Sons, Ltd.     

Suitability of alternative fatty food simulants to study the effect of thermal and microwave heating on overall migration of plastic packaging

The suitability of alternative fatty food simulants on overall migration determination under thermal treatment and microwave heating were analysed for different plastic materials commonly used for packs subjected to thermal treatment or microwave heating. Elevated temperature and microwave heating increased overall migration. The results demonstrated that polymer–simulant affinity plays a large role in determining the suitability of the alternative simulant. For PA/PE, ethanol 95% represented the best alternative fatty food simulant to reproduce overall migration with olive oil. PVC presented a high overall migration. Microwave heating increased migration up to 45 mg/dm². For PVC, isopropanol was able to reproduce olive oil even after microwave heating. For PP, none of the alternative fatty food simulants were able to reproduce overall migration with olive oil. PP presented high inert behaviour. Microwave heating did not produce a significant increase in overall migration; meanwhile, the time of exposure produced a more significant migration. Copyright © 2004 John Wiley & Sons, Ltd.     

PVC thermoformed containers for food packaging: establishment of a rapid extraction test for overall migration limit compliance testing

In order to demonstrate compliance with the overall migration limit given in amended EC Directive 90/128/EEC, overall migration tests are usually performed on the finished food packaging with food stimulants. For packaging converters, in particular, who thermoform a wide range of containers from an extruded sheet, the cost of testing for compliance can be prohibitive. However, the Directive also allows compliance to be demonstrated by use of a ‘more severe test’. In this study a ‘more severe test’ has been developed for PVC and VC/VA co-polymer materials involving extraction with methanol or a methanol/water mixture and evaporation to dryness. This procedure has been optimised so that it is simple and rapid to perform and gives slightly higher results for the extruded sheet compared to overall migration tests conducted with fatty and aqueous food simulants. Results are presented demonstrating the rapid extraction test to be a ‘more severe test’ and that it could be used by converters in conjunction with good manufacturing practice (GMP) to demonstrate compliance with the overall migration limit in a cost-effective way. © 1997 John Wiley & Sons, Ltd.     

Investigations on Overall Migration of Various Plastic Materials and Articles Used in Contact with Foodstuffs

The results of overall migration tests for a wide range of plastic packagings and other domestic and imported articles made of plastic intended to come into direct contact with foodstuffs are presented. In these tests the simulants specified in Directive 85/572/EEC as well as isooctane and 95% ethanol (so called alternative substances) have been used. Checking the overall migration into the four simulants specified in the above mentioned Directive it was found that the limit (equal to 10 mg/dm² according to Directive 90/128/EEC) was exceeded in a few, very specific, cases. Comparison between overall migration from some articles into sunflower oil and isooctane was also examined. The results indicate that though the use of isooctane as an alternative substance significantly simplifies the testing procedure, exceeding an overall migration limit into isooctane is not equivalent to exceeding the limit of migration into sunflower oil. In such cases only migration into typical fatty food simulants can have a deciding meaning. © 1997 John Wiley & Sons, Ltd.     

Static subcritical water extraction combined with anion exchange disk sorption for determining chlorinated acid herbicides in soil

Static subcritical water extraction (SbWE) was coupled with collection on a strong anion exchange (SAX) disk for the determination of chlorinated acid herbicides and their esters in soil. With 100-150 degrees C water, esters were hydrolyzed into their acid form, and the herbicide acids extracted by subcritical water were trapped onto/into a SAX disk as the extraction cell was cooled. The trapped solutes were then derivatized for gas chromatographic (GC) analysis by placing the disk into a GC autosampler vial containing 1 mL of N,O-bis(trimethylsilyl)trifluoroacetamide derivatizing reagent. With the static SbWE/SAX disk extraction, nearly quantitative recoveries (typically over 80%) were obtained at 100 degrees C for 30 min in the extraction of herbicide acids and esters spiked on several different soils covering a range of organic content from 0.3 to 12%. Good agreements were reached between this method and EPA method 8151 for aged spiked soils. Detection limits of the static SbWE/SAX disk extraction were from 0.05 to 0.5 ppm and from 0.01 to 0.5 ppm using GC/electron capture detector and GC/mass spectrometry, respectively. The method is fast and simple and uses a small amount of organic solvent.     

Design of experiments in environmental chemistry studies: example of the extraction of triazines from soil after olive cake amendment

The disposal of natural, composted and vermicomposted olive cake for modifying the fate of triazine herbicides with different physicochemical properties (terbuthylazine, cyanazine, simazine and prometryn) has been tested. Experimental design (surface response methodology plus desirability function) to multicriteria optimization was carried out to evaluate both dose and type of amendment to retain the cited analytes and to develop two simple and low cost analytical methods for extracting triazines from soil. From a methodological point of view, classical and D-optimal designs were employed depending on the problem. Thus, the best combination of soil amount and solvent ratio, the most important parameters affecting triazine extraction from soil, was looked for by means of Central Composite Designs. Under the optimized conditions, the range of triazines recovery was 75-85% for shaking extraction and 87-107% for ultrasonic extraction. Regarding the amendment assay, D-optimal design was selected to keep the reliability of the estimations. Natural olive cake added to the soil at a high dose (8%) reduced herbicide recovery to ca. 50-60% for terbuthylazine, prometryn and simazine, while cyanazine recovery was negligible. Design of experiment provides an efficient working strategy to explore those conditions which ensure the optimum or target value of several responses evaluated simultaneously.     

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.     

Effect of high‐pressure food processing on the mass transfer properties of selected packaging materials

The effect of high‐pressure processing (HPP) on the total migration into distilled water and olive oil and on the barrier properties of four complex packaging materials were evaluated. The films were polyethylene/ethylene‐vinyl‐alcohol/polyethylene (PE/EVOH/PE), metallized polyester/polyethylene, polyester/polyethylene (PET/PE), and polypropylene‐SiOx (PPSiOx). Pouches made from these films were filled with food simulants, sealed and then processed at a pressure of 400 MPa for 30 min, at 20 or 60°C. Pouches kept at atmospheric pressure were used as controls. Prior to and after treatment, all films were evaluated for their barrier properties (oxygen transmission rate and water vapour transmission rate) and ‘Total’ migration into the two food simulants. In the case of water as the food stimulant, a low ‘Total’ migration was observed and even a lower one after the HPP treatment. In the case of oil as the food simulant, a higher ‘Total’ migration was found compared to the control as a result of damage to the structures during the HPP treatment. The gas permeability of the films increased after the HPP, compared to the control, due to damages in the structure caused during the treatment. The PET/PE film presented minimum changes in properties after HPP. Copyright © 2010 John Wiley & Sons, Ltd.     

Recycling of solvent used in a solvent extraction of petroleum hydrocarbons contaminated soil

The application of water washing technology for recycling an organic composite solvent consisting of hexane and pentane (4:1; TU-A solvent) was investigated for extracting total petroleum hydrocarbons (TPH) from contaminated soil. The effects of water volume, water temperature, washing time and initial concentration of solvent were evaluated using orthogonal experiments followed by single factor experiments. Our results showed that the water volume was a statistically significant factor influencing greatly the water washing efficiency. Although less important, the other three factors have all increased the efficacy of water washing treatment. Based on a treatment of 20 g of contaminated soil with a TPH concentration of 140 mg g(-1), optimal conditions were found to be at 40°C, 100 mL water, 5 min washing time and 660 mg g(-1) solvent. Semi-continuous water extraction method showed that the concentration of the composite solvent TU-A was reduced below 15 mg g(-1) d.w. soil with a recovery extraction efficiency >97%. This finding suggests that water washing is a promising technology for recycling solvent used in TPH extraction from contaminated soils.     

橄榄油中角鲨烯含量的气相色谱/质谱法分析

本文建立了橄榄油中角鲨烯含量的GC/MS分析方法.橄榄油中的脂肪酸甲酯化,角鲨烯同步萃取于石油醚-苯(1+1)溶剂中,经强极性毛细管柱SP-2560分离,质谱选择离子监测对角鲨烯进行定量测定.该方法在0.01-0.50mg/mL范围内线性关系良好,相关系数为0.9999,最小检测限为1.80ng/mL,方法回收率在99...     

膜萃取去除水中氯仿的研究

采用煤油－氯仿－水为实验体系,在两种不同型号的的聚丙烯中空纤维膜器中进行了连续逆流膜萃取过程的研究．计算了基于水相的总传质系数Ｋｗ,分析了实测值与计算值之间的偏差．实验结果表明,传质由水相边界层控制,壳程的非理想流动是造成偏差的主要原因．通过计算传质单元高度ｈＨＴＵ及测定萃取前后氯仿水溶液的ＣＯＤ值,证明了中空纤维膜萃取去除水中氯仿的高效性     

Pressurized fluid extraction of nonpolar pesticides and polar herbicides using in situ derivatization

Analysis of polar acidic herbicides has traditionally presented a challenge because of their strong adsorption to and ionic interactions with soil. One approach which has been successful for extraction of these polar compounds from soil is supercritical fluid extraction (SFE) coupled with in situ derivatization. This technique involves the addition of common derivatization reagents directly into the extraction chamber, where the acid herbicides are derivitized to extractable esters or ethers. This study describes the application of an in situ derivatization technique to pressurized fluid extraction (PFE) for the herbicides 2,4-D, 2,4,5-T, dicamba, silvex, trichlopyr, and bentazone. The efficiency of in situ derivatization PFE for these analytes is compared with a conventional basic extraction method followed by ex situ derivatization. The variables of temperature, pressure, static extraction time, and derivatization-reagent amount were optimized for recovery of these analytes from soil. Average recovery for these six analytes was 107% for in situ derivatization PFE from spiked sand, 93% for the same method from a high-concentration spiked soil (50 mg/kg), and 68% for the optimized in situ derivatization PFE method from low-concentration soil (0.5 mg/kg). The in situ derivatization PFE method has substantial advantages of simplicity of methodology and reduction in extraction time compared with the conventional technique. A second in situ derivatization PFE strategy was investigated using sodium EDTA in the extraction chamber for the extraction of 2,4-D from soil. Preliminary results demonstrate improved recovery with the use of Na4EDTA. Extraction efficiency of PFE for nonpolar organochlorine insecticides and slightly polar triazine herbicides from soil is also presented and compared with that of Soxhlet extraction.     

微波辅助萃取/分光光度法快速测定抗菌纺织品中的三氯生

为了测定抗菌纺织品中三氯生的含量,本文以二氯甲烷为萃取溶剂,采用微波萃取技术萃取抗菌纺织品中的抗菌剂三氯生。萃取液蒸发至干后,用甲醇定容,然后以甲醇为参比溶液,在282nm波长下测定其吸光度,从而建立了一种测定抗菌纺织品中的抗菌剂三氯生的分光光度方法,并对萃取条件、方法的线性关系、精密度、回收率、检出限等进行了研究。三氯生在0.2-80mg/L范围内呈现良好的线性关系,线性相关系数为0.9998,回收率为91.98%-104.94%,相对标准偏差均小于6%,检出限为0.1mg/kg(S/N=3)。采用该方法对市售抗菌纺织品进行检测,发现部分抗菌纺织品中使用高含量的三氯生。     

气相色谱法测定食品包装纸中饱和烃矿物油迁移量

本文运用气相色谱技术建立了食品包装纸中饱和烃矿物油迁移量检测方法.本方法检出限和定量限分别为2.28mg/L和6.84mg/L,采用低、中、高3个浓度水平对样品进行加标回收试验,加标回收率为95.46%~106.38%,相对标准偏差<4.0%.优质原生纸样品食品模拟物未检出矿物油,而回收食品包装纸中均存在不同矿物油迁移量,尤其是含有油墨、石蜡和粘合剂等的回收纸.     

精炼吊瓜籽油的脂肪酸分析

对压榨吊瓜籽毛油进行了精炼,计算出得率为54%。采用GC分析、比较了吊瓜籽精油、橄榄油和菜籽油的脂肪酸组分,表明吊瓜籽油中油酸、亚油酸含量为8.48%、33.6%,亚油酸含量高于橄榄油(8.48%)和菜籽油(13.03%).经过GC-MS确证,吊瓜籽含有丰富的角鲨烯(22.7%),是营养保健物质的新型来源.     

Extraction of antioxidants from olive mill wastewater and electro-coagulation of exhausted fraction to reduce its toxicity on anaerobic digestion

Liquid-liquid extraction was used in order to recover phenolic compounds from centrifuged olive mill wastewater (OMW), a polluting by-product of olive oil production process, and to reduce their toxicity for a subsequent aerobic or anaerobic digestion. Phenolic compounds were identified in untreated and treated OMW by gas chromatography coupled to mass spectrometry (GC-MS). The experimental results of ethyl acetate extraction showed that the monomers recovery efficiency was over 90%. This pre-treatment resulted in the removal of the major LMM phenolic compounds and a small part of HMM polyphenols. The aerobic treatment of the exhausted OMW fraction removed 78.7% of the soluble COD. In the case of anaerobic digestion at OLR ranged from 1 to 3.5 gCOD l(-1)day(-1), methanisation process exhibited high methane yield as 0.3 l CH4 produced per g COD introduced and high COD removal (80%). However, a disruption of the process was observed when the OLR was increased to 4.5 gCODl(-1)day(-1). A pre-treatment by electro-coagulation resulted in decreasing the toxicity and enhancing the performance of methanisation operated at higher OLR from 4 to 7.5 gCODl(-1)day(-1).     

Determination of hydroxytyrosol in plasma by HPLC

Hydroxytyrosol (2-(3,4-dihydroxyphenyl)ethanol), a phenolic compound present in extravirgin olive oil, has been reported to contribute to the prevention of cardiovascular disease. The present study describes an accurate and reproducible reversed-phase HPLC method to measure hydroxytyrosol in plasma. This compound was extracted from acidified plasma by solid-phase extraction using an Oasis HLB copolymer. The plasma sample was rinsed with water and methanol in water (5:95; v/v). Hydroxytyrosol was eluted with methanol, which was subsequently evaporated under a nitrogen stream. Analysis by HPLC with diode array-UV detection was carried out using a C18 column and a gradient elution with acidified water and methanol/acetonitrile (50:50; v/v). The method was validated by the analyses of plasma samples spiked with pure hydroxytyrosol, obtaining a linear correlation (0.9986) and precision with a coefficient of variation ranging from 0.79 to 6.66%. The recovery was approximately 100%, and the limit of detection was 37 ng/mL. The oral administration of hydroxytyrosol to rats and its subsequent detection in plasma showed that the method is suitable for pharmacokinetic studies.     

Migration of Tinuvin P,a UV stabilizer,from PET bottles into fatty‐food simulants

Tinuvin P migration from Polyethyleneterephthalate (PET) bottles was investigated using several fatty‐food simulants such as olive oil, soybean oil, n‐heptane and iso‐octane, at exposure conditions of 2–10 days at 40°C (total immersion). The stability of several UV stabilizers (BHT, Cyasorb UV 5411, Tinuvin P, Tinuvin 326 and Tinuvin 327) in n‐heptane and iso‐octane was also studied. After 10 days at 40°C, losses of 6% and 10% in iso‐octane and n‐heptane respectively, were verified for Tinuvin P. Other UV stabilizers at the same experimental conditions showed higher losses (up to 30% for Tinuvin 327). These results confirm that, when carrying out specific migration studies, the stability of the substance of interest should be established in the food simulant to avoid underestimating the real migration behaviour. In order to quantify UV stabilizer migration, n‐heptane and iso‐octane solutions were concentrated and directly analysed by SIM mode GC–MS. For olive and soybean oils, Tinuvin P was isolated using size‐exclusion chromatography and quantified by SIM mode GC–MS. Iso‐octane proved to be a more suitable fatty‐food simulant than n‐heptane for the migration study of Tinuvin P from PET. Higher levels of Tinuvin P migrated to olive and soybean oils rather than to n‐heptane. These results suggest that the MERCOSUL recommended official methods for specific migration studies should be revised, since the migration levels using n‐heptane as a fatty‐food simulant could be underestimated when compared to edible oils. Copyright © 1999 John Wiley & Sons, Ltd.     

Migration of Cyclic Monomer and Oligomers from Polyamide 6 and 66 Food Contact Materials into Food and Food Simulants: Direct Food Contact

Cyclic monomer and oligomers are the major migrating substances from polyamide (PA) food contact materials. An increase of caprolactam (+44%) and cyclic oligomer content (+27%, incl. caprolactam) in PA6 was observed by thermal treatment, here by extrusion of a PA6 film from a granulate. Migration experiments with a PA6 and a PA66 packaging film were carried out into food simulants according to directives 85/572/EEC and 82/711/EEC. Contact conditions (2 h/100°C) were chosen for a heat treatment of the food in the packaging, in this case production of scalded sausage. Aqueous and ethanolic food simulants clearly revealed to be the worst case for migration of cyclic PA6 and PA66 monomer and oligomers. Migration of cyclic oligomers into oil was one order of magnitude lower. No migration could be observed into isooctane (<8 µg dm^?2). The substitutes for oil, 95% ethanol and isooctane, were inapplicable for simulating migration of cyclic oligomers into oil. Caprolactam showed different migration behaviour compared with cyclic oligomers, migrating into oil and water to the same extent depending on contact conditions. Fifty percent of the extractable caprolactam migrated from a PA6 sausage casing into scalded sausage (4.2 mg kg^?1), residual 41% apparently were extracted by the boiling medium or during pretreatment (soaking) of the casing. Potential migration of caprolactam and cyclic oligomers from a PA6 tea bag was found to be 18% of the specific migration limit for caprolactam and 36% of the overall migration limit. Copyright © 2014 John Wiley & Sons, Ltd.     

Evaluation of Different Conditions of Contact for Caprolactam Migration from Multilayer Polyamide Films into Food Simulants

Caprolactam, the polyamide 6 (PA‐6) monomer, can migrate during food processing. At cooking temperatures, migration is accelerated and plastic components could degrade, giving off low molecular mass compounds, which can migrate into food. In this work, caprolactam migration from multilayer films containing PA‐6 for meat foodstuffs and cheese packaging was performed at contact conditions of 40°C/10 days and 100°C/30 min. The migration into water ranged from 0.89 to 1.22 mg/dm² and 0.92 to 1.21 mg/dm², into 3% acetic acid from 1.29 to 1.74 mg/dm² and 1.13 to 1.62 mg/dm² and into olive oil from 1.18 to 1.98 mg/dm² and 0.50 to 0.80 mg/dm² for films intended for meat foodstuffs for 10 days at 40°C and 30 min at 100°C, respectively. Among PA‐6 films used for cheese, caprolactam migration into water ranged from 0.17 to 0.91 mg/dm² and 0.74 to 1.04 mg/dm², into 3% acetic acid from 1.15 to 1.26 mg/dm² and 1.11 to 1.37 mg/dm² and into olive oil from 0.23 to 0.83 mg/dm² and 0.37 to 0.56 mg/dm² for 10 days at 40°C and 30 min at 100°C, respectively. Caprolactam migration evaluation into water and 3% acetic acid at 100°C/30 min could replace the need to apply the test at 40°C/10 days, since similar results were obtained under both conditions. In the case of PA‐6 for meat foodstuffs, caprolactam migration into olive oil was highly affected by different conditions of contact, showing values two to three times higher at 40°C/10 days than at 100°C/30 min. For cheese films, caprolactam migration into olive oil was higher at 40°C for 10 days. Copyright © 2013 John Wiley & Sons, Ltd.