固相萃取-气相色谱-质谱联用法筛查食用菌中的农药残留

采用气相色谱-质谱联用结合NAGINATA™软件建立了筛查食用菌中多种农药残留的分析方法。采用乙腈提取,Carbon-NH2固相萃取小柱净化,气相色谱-质谱联用检测后NAGINATA™软件全智能分析,对照每个化合物的质谱质量精度以及质谱谱图的谱库给出匹配度,通过保留时间锁定对化合物作定性判断。结果表明,18 种农药在香菇中检出限为0.001～0.050 mg/kg;平均回收率为77%～110%;相对标准偏差为1.1%～6.9%。应用所建立的方法对35 个市售食用菌样品进行了筛查,检测出2 种农药残留,残留量均低于GB 2763-2014《食品中农药最大残留限量》的限量。该方法操作便捷、快速高效,适用于食用菌中农药多残留的快速筛查。     

气相色谱-质谱联用法测定植物油料中角鲨烯的含量及方法比较

建立气相色谱-质谱联用法（Gas chromatography mass spectrometry,GC-MS/MS）分离和测定植物油料中角鲨烯的方法。用氢氧化钾-乙醇溶液超声皂化后,正己烷溶液萃取,氮吹浓缩,正己烷溶解,提取物经HP-5MS柱分离后进入质谱仪检测,外标法定量。该方法在角鲨烯浓度0.1~100.0 mg/L的范围内具有良好的线性关系（r=0.9998）,方法的精密度良好RSD为1.00%~3.35%,加标回收率为83.60%~110.44%,平均加标回收率为98.89%,方法的检出限（RSN=3）为0.10 mg/L。通过气相色谱质谱联用与气相色谱对四类实际油料样品的分析表明,气相色谱质谱联用方法具高效快速、操作简单、污染小以及检测灵敏度高等优点,可以满足植物油料中角鲨烯的快速、高通量检测。     

色谱质谱技术在食品安全分析检测中的应用

食品安全是关系国计民生的重要议题。准确、深入、高效的食品安全分析检测技术是防控食品安全事件发生及处理相关贸易纠纷、立法追责的基础和保障。色谱质谱技术作为高效的分离和检测手段是目前食品安全分析领域最重要、最主流的技术手段。近年来,色谱质谱领域的新发展也推动了食品安全分析检测向更快速,更有效,更可靠,更安全的目标迈进,本综述就其中最重要并有望代表未来食品安全分析发展趋势的色谱质谱技术做了总结和点评。如用于食品样品预处理的固相微萃取技术;气相色谱及气相色谱质谱联用技术中的快速气相色谱方法及其与质谱联用方法,二维气相色谱方法及其与质谱联用方法;液相色谱及液相色谱质谱联用技术中的超高效液相色谱及其与质谱联用方法,毛细管液相色谱和纳流液相色谱及其与质谱联用方法,超临界色谱及其与质谱联用方法,二维液相色谱及其与质谱联用方法;质谱分析技术中的超高分辨率质谱方法,常压敞开式离子源质谱技术等。     

真空冷却对酱排骨风味的影响

为研究真空冷却对酱排骨风味的影响,采用顶空固相微萃取-色谱-质谱联用技术和气相色谱-离子迁移谱测定自然冷却和真空冷却的酱排骨中的挥发性成分,再结合快速气相色谱电子鼻进行主成分分析。在2种不同冷却方式处理的酱排骨中共检测到83种挥发性化合物,包括酯类5种、醇类17种、醚类4种、酮类8种、烃类17种、醛类19种、酸类8种、酚类2种及杂环类化合物3种,2种酱排骨中各种挥发性成分的种类及相对百分含量有明显差异。快速气相色谱电子鼻检测结果显示2种酱排骨容易根据气味差异被区分开来,试验结果可以为酱排骨在真空冷却中的应用提供理论依据。     

落叶松树皮快速热解油的成分分析研究

利用红外光谱、差热扫描以及气相色谱-质谱联用等先进的分析手段对落叶松树皮快速热解油的主要成分进行了分析.结果表明:落叶松树皮快速热解油的成分非常复杂,含有很多酚类、醛类、酮类物质以及不饱和的C=C键和柔性集团;快速热解油中酚类物质的含量约为33%,不同的酚类物质反应活性不同,其中含有三反应活性点、二反应活性点和单反应活性点的酚类物质占热解油的比例分别为:20%、10%、3%;在140℃的条件下,热解油中的酚类物质和醛类物质发生的固化放热反应和纯酚醛树脂相类似.     

色谱-质谱联用技术在食品检测中的应用

色谱-质谱联用技术是近年来迅速发展的一类技术。本文综述了色谱-质谱联用技术在食品检测中的应用,分别介绍了气相色谱-质谱联用技术、液相色谱-质谱联用技术、离子色谱-质谱联用技术的原理和技术特点,并结合具体实例对各项技术的应用加以阐述。在食品检验过程中,应根据未知样品的特点,选择适当的色谱-质谱联用技术,建立起高效、灵敏的检测方法,对其进行定性定量分析,以保证食品安全。     

纺织品中禁用偶氮染料的有效测定

通过改进气相色谱-质谱联用方法的测试条件,在提高24种禁用芳香胺物质检测效率的同时,实现了2,4-二氨基甲苯与其3种同分异构体的有效鉴别,建立了一种快速、有效地检测纺织品中禁用偶氮染料的方法.     

基于二维色谱及其联用技术筛查乳及乳制品中外源性风险物质的分析方法研究进展

近年来,随着色谱技术飞速发展,二维气相色谱与二维液相色谱等高分辨色谱及其联用技术在乳品质量安全领域被广泛应用。乳及乳制品为复杂基质,基质组分种类多,含量差异性大,色谱共流出化合物给外源性风险物质分离检测带来困难。二维色谱具有峰容量大,分辨率和精确度高等优势,与质谱技术进行有效联用,可实现乳及乳制品中外源性风险物质的高通量、快速筛查。本文论述乳制品中风险物质及二维色谱的技术原理、工作流程,综述近十年来二维色谱在乳及乳制品中风险物质筛查研究的应用进展,对其发展趋势及相关应用前景进行了总结展望。     

气相色谱-串联质谱在食品农药残留检测中的应用进展

正气相色谱-质谱联用(GC-MS)综合气相色谱和质谱两种检测方法的特点,既具有气相色谱法分离能力较强的特点,又具有质谱检测法对化合物的结构准确鉴定的特点,能同时准确且快速地检测食品中微量的多种农药残留及其衍生物质。因此,在各国家食品检测中得到较为广泛的应用,笔者根据实际工作经验从各个层面分析现阶段我国食品农药残留检测中使用到的气相色谱-质谱联用法,并以此     

顶空固相微萃取-气质联用法测定五味子酒挥发性风味成分

采用顶空固相微萃取法并结合气相色谱-质谱联用技术对五味子酒的挥发性风味成分进行分析。共检测出五味子酒挥发性风味成分36种,确定结构31种,其风味物质组成为醇类(74.03%,7种)、酯类(17.21%,3种)、芳香族(1.83%,8种)、烯烃类(1.06%,4种)、酸类(0.81%,4种)、杂环类(0.37%,3种)和酚类(0.27%,2种)。顶空固相微萃取法并结合气相色谱-质谱联用技术能简易、快速地检测出五味子酒中的醇类、酯类、芳香族和烯烃类等挥发性风味成分,为五味子酒的进一步研究与开发提供科学依据。     

Migration of styrene and ethylbenzene from virgin and recycled expanded polystyrene containers and discrimination of these two kinds of polystyrene by principal component analysis

ABSTRACT

The migration of styrene and ethylbenzene from virgin and recycled expanded polystyrene (EPS) containers into isooctane was investigated using gas chromatography-mass spectrometry (GC-MS). EPS containers were in two-sided contact with isooctane at temperatures of 25 and 40°C. It was shown that recycled EPS gave greater migration ratios compared with virgin EPS, which indicated that styrene and ethylbenzene migrated more easily from recycled EPS. In addition, an analytical method to distinguish between virgin and recycled EPS containers was established by GC-MS followed by principal component analysis (PCA). The relative peak area of the identified compounds was used as input data for PCA. Distinct separation between virgin and recycled EPS was achieved on a score plot. Extension of this method to other plastics may be of great interest for recycled plastics identification.     

Quality and safety aspects of reusable plastic food packaging materials: influence of reuse on intrinsic properties

The aim of the project was to develop a comprehensive package of quality assurance criteria for use by the industry and by regulatory authorities to ensure the quality and safety-in-use (sensory, microbiological and chemical safety) of reused plastics for food packaging. The paper describes the investigations into potential adulteration effects by reuse on the intrinsic properties of plastics in more detail. The plastic articles investigated were bottles of polyethylene terephthalate (PET) or polycarbonate (PC) and vending cups of polypropylene (PP). The influence of repeated use on the migration of plastic constituents, degradation products of plastic additives, barrier properties and surface characteristics were investigated. The overall conclusion was that the investigated intrinsic properties of the refillable articles were not significantly influenced by repeated use. Only the hydrophobicity of the refillable PC and PP articles seemed to be influenced by repeated washing. PC bottles washed 15 times were significantly less hydrophobic than unwashed bottles.     

Effect of temperature, plastic type and virginity on the water uptake of sawdust/plastic composites

Water absorption of wood plastic composites (WPCs) manufactured from sawdust and virgin and recycled plastics (HDPE and PP) was studied. Wood flour was prepared from sawdust and mixed with different virgin or recycled plastics at 50% by weight fiber loading. The mixed materials were compression molded into panels. Water absorption of manufactured WPCs was determined after 2 and 24 h immersion in distilled water at different temperatures (25, 50 and 70 °C). WPCs containing recycled plastics exhibited higher water absorption especially when the two recycled plastics were mixed together. Immersion temperature had a significant effect on water absorption.     

Evaluation of some screening methods for the analysis of contaminants in recycled polyethylene terephthalate flakes

A range of different analytical techniques were used to test recycled polyethylene terephthalate (PET) flakes for potential chemical contaminants. The techniques used were headspace gas chromatography coupled to mass spectrometry (GC-MS), liquid extraction followed by GC-MS, supercritical-fluid extraction followed by GC-MS, and migration testing followed by elemental analysis using inductively coupled plasma mass spectroscopy (ICP-MS). The PET samples were 50 representative samples taken from 600 that had been collected throughout Europe and which had been screened for potential contaminants using a single technique of high-temperature GC-MS. Six of the 50 samples tested had been spiked with a selection of model contaminants, three samples were virgin PET flakes and two of the samples were from supercleaning processes. All samples were analysed 'blind' in this exercise. The qualitative results showed that most of the contaminants came from the first use, being flavour-aroma compounds from soft drinks. The quantitative analysis found concentrations under a few mg kg^-1 in the polymer, except for the spiked samples. Element migrations were low and only calcium, silicon and sodium had median migrations above 50 μg l^-1. This in-depth analysis of recycled PET flakes did not identify any significant contaminants that had not already been detected by the high-temperature static GC-MS screening method, thus demonstrating its utility.     

Rapid classification of virgin and recycled EPS containers by Fourier transform infrared spectroscopy and chemometrics

ABSTRACT

A rapid and sensitive method for classification of virgin and recycled expanded polystyrene (EPS) food containers was developed using Fourier transform infrared spectroscopy (FTIR) and chemometrics. This method includes preparing a transparent film by dissolution, examining by FTIR and developing classification models. The degradation of EPS containers occurring during the recycling process was reflected by the carbonyl region of the infrared spectrum which was used as variables for multivariate data analysis. PCA was used to reduce the data dimension and view the sample similarities. Soft independent modelling of class analogy (SIMCA), partial least squares-discrimination analysis (PLS-DA) and linear discrimination analysis (LDA) were applied to construct three classification models. The best discrimination results were obtained by an LDA model, with all samples correctly classified. PLS-DA and SIMCA could not classify the recycled EPS samples with low levels of adulteration. When applying this method to commercially available EPS containers, about 45% of samples were shown to contain recycled polystyrene resins. It is concluded that the carbonyl region of the infrared spectra coupled with chemometrics could be a powerful tool for the classification of virgin and recycled EPS food containers.     

Studies on the usability of recycled PET for food packaging applications

The need of and opportunities for recycling of plastics for food packaging have been recognized, and a lot of work to find meaningful and cost-effective solutions to this issue is in progress. The safety of recycled plastics for food contact use is largely dictated by the ability of post-consumer contaminants to absorb into recycled materials and later diffuse from recycled plastics into the food. The objective of the present study was to establish a suitable analytical approach to identifying and quantifying any chemical substances that derive from the earlier use and remain in the polyethylene terephthalate (PET). A simple gas chromatographic technique using flame ionization detection was developed to allow quantification of solvent extractable compounds in a series of recycled PET samples. Identification of the nature and extent of contaminants in the PET samples was also attempted using GC/MS analysis.     

食品包装塑料制品中掺杂回收塑料的分析及 检测方法研究现状

随着高分子材料工业的飞速发展,塑料制品已广泛应用于食品包装行业,同时食品包装塑料制品中掺杂回收塑料的问题也日益严重。本文综述了食品包装塑料制品中掺杂回收塑料的分析及检测方法研究现状,重点讨论了红外光谱法、热分析法、分子量及其分布法、气相色谱-质谱联用法、机械性能法等分析方法的应用现状及可行性。同时对该领域的发展趋势进行了展望。     

Post-consumer contamination in high-density polyethylene (HDPE) milk bottles and the design of a bottle-to-bottle recycling process.

Six hundred conventional recycled HDPE flake samples, which were recollected and sorted in the UK, were screened for post-consumer contamination levels. Each analysed sample consisted of 40-50 individual flakes so that the amount of analysed individual containers was in the range 24,000-30,000 post-consumer milk bottles. Predominant contaminants in hot-washed flake samples were unsaturated oligomers, which can be also be found in virgin high-density polyethylene (HDPE) pellet samples used for milk bottle production. In addition, the flavour compound limonene, the degradation product of antioxidant additives di-tert-butylphenol and low amounts of saturated oligomers were found in higher concentrations in the post-consumer samples in comparison with virgin HDPE. However, the overall concentrations in post-consumer recycled samples were similar to or lower than concentration ranges in comparison with virgin HDPE. Contamination with other HDPE untypical compounds was rare and was in most cases related to non-milk bottles, which are <2.1% of the input material of the recycling process. The maximum concentration found in one sample of 1 g was estimated as 130 mg kg(-1), which corresponds to a contamination of 5200-6500 mg kg(-1) in the individual bottle. The recycling process investigated was based on an efficient sorting process, a hot-washing of the ground bottles, and a further deep-cleaning of the flakes with high temperatures and vacuum. Based on the fact that the contamination levels of post-consumer flake samples are similar to virgin HDPE and on the high cleaning efficiency of the super-clean recycling process especially for highly volatile compounds, the recycling process investigated is suitable for recycled post-consumer HDPE bottles for direct food-contact applications. However, hand-picking after automatically sorting is recommended to decrease the amount of non-milk bottles. The conclusions for suitability are valid, provided that the migration testing of recyclate contains milk bottles up to 100% and that both shelf-life testing and sensorial testing of the products are successful, which are topics of further investigations.     

Migration of bisphenol A from plastic baby bottles,baby bottle liners and reusable polycarbonate drinking bottles

Human exposure to bisphenol A (BPA) has recently received special attention. It has been shown that exposure to BPA may occur through the consumption of beverages or foods that have been in contact with polycarbonate (PC) plastic containers or epoxy resins in food packaging. A BPA migration study was conducted using a variety of plastic containers, including polycarbonate baby bottles, non-PC baby bottles, baby bottle liners, and reusable PC drinking bottles. Water was used to simulate migration into aqueous and acidic foods; 10% ethanol solution to simulate migration to low- and high-alcoholic foods; and 50% ethanol solution to simulate migration to fatty foods. By combining solid-phase extraction, BPA derivatization and analysis by GC-EI/MS/MS, a very low detection limit at the ng l^?1 level was obtained. Migration of BPA at 40°C ranged from 0.11 µg l^?1 in water incubated for 8 h to 2.39 µg l^?1 in 50% ethanol incubated for 240 h. Residual BPA leaching from PC bottles increased with temperature and incubation time. In comparison with the migration observed from PC bottles, non-PC baby bottles and baby bottle liners showed only trace levels of BPA. Tests for leachable lead and cadmium were also conducted on glass baby bottles since these represent a potential alternative to plastic bottles. No detectable lead or cadmium was found to leach from the glass. This study indicated that non-PC plastic baby bottles, baby bottle liners and glass baby bottles might be good alternatives for polycarbonate bottles.     

Identification and quantification of the migration of chemicals from plastic baby bottles used as substitutes for polycarbonate

The results of a study on the analytical identification and quantification of migration of chemicals from plastics baby bottles found in the European Union market made of materials that are now present as substitutes for polycarbonate (PC) are reported. A total of 449 baby bottles with a focus on first age or sets of bottles were purchased from 26 European Union countries, Canada, Switzerland and the USA. From this collection, which contained several duplicates, a total of 277 baby bottles were analysed. The materials included different types of plastic such as PC, polyamide (PA), polyethersulphone (PES), polypropylene (PP), but also silicone, and from the United States a co-polyester marketed under the trade name Tritan?. The bottles were subjected to the conventional migration test for hot fill conditions, i.e. 2?h at 70°C. The simulant used was that specified in European Union legislation (2007/19/EC) for milk, i.e. 50% ethanol. In a first phase 1, migration was conducted since the scope of this investigation was a screening rather than a true compliance testing check. Second and third migrations were performed on selected articles when migrated substances exceeded limits specified in the legislation. In order to verify some materials, a portion of the bottle was cut to run an FT-IR fingerprint to confirm the nature of the polymer. The migration solutions in general showed a low release of substances. Results showed that bottles made of PP and silicones showed a greater number of substances in the migration solutions and in greater quantity. Chemicals from PP included alkanes, which could be found in >65% of the bottles at levels up to 3500?μg?kg?1; and benzene derivatives in 17% of the baby bottles and found at levels up to 113?μg?kg?1. Some substances were found on a regular basis such as plasticisers, esters and antioxidants (e.g. tris(2,4-di-tert-butylphenyl)phosphate, known as Irgafos 168. Some substances found were not included in the Community positive list, which means that those should not be found even in the first migration. Such substances included 2,6-di-isopropylnaphthalene (DIPN), found in 4% of the bottles at levels up to 25?μg?kg?1, 2,4-di-tert-butyl phenol (in 90% of the bottles at levels up 400?μg?kg?1). Moreover, bisphenol A (BPA) was detected and quantified in baby bottles made of PA, but limited to one brand and model specific (but labelled BPA free). Results for baby bottles made of silicone also indicated the presence of components, e.g. potentially coming from inks (benzophenone, diisopropyl naphtahalene - DIPN, which could come for example from the presence of instruction leaflets in the bottles). In the case of silicone, phthalates were also found in relevant concentrations, with levels for DiBP and DBP from the first migration test of 50-150?μg?kg?1 and DEHP at levels 25-50?μg?kg?1.