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。     

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。     

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 diethylhexyladipate and acetyltributylcitrate in aqueous extracts after cloud point extraction coupled with microwave assisted back extraction and gas chromatographic separation

The determination of commercial plasticizers (di-(2-ethylhexyl)adipate (DEHA) and acetyl tributyl citrate (ATBC)) in aqueous solutions is described. The newly proposed technique of applying microwaves to cloud point extracts in order to enable combination with gas chromatographic analysis has been used for this purpose. Both plasticizers were entrapped in the micelles of the non-ionic surfactant Triton X-114 and removed from the bulk phase by centrifugation. Micellization was enhanced by increasing the ionic strength of the solution with concentrated NaCl. Extraction recoveries of the proposed method were over 95% for water and 3% (w/v) aqueous acetic acid and over 85% for 10% (v/v) aqueous ethanol, respectively. The calibration curves obtained, following the proposed methodology have a linear range between 50 and 2000 microg/L for each analyte while the detection limits were as low as 15 and 19 microg/L for DEHA and ATBC, respectively, with an RSD below 5% even for low concentrations. As an analytical demonstration the proposed methodology was applied for the determination of the migration levels of the selected plasticizers from a PVC food packaging film into aqueous simulants.     

Analysis of 16 phthalic acid esters in food simulants from plastic food contact materials by LC‐ESI‐MS/MS

An RP LC‐ESI‐MS/MS method for the determination of the migration of 16 primary phthalic acid esters from plastic samples has been developed using distilled water, 3% acetic acid, 10% alcohol, and olive oil as food simulants. Detection limits were 1.6–18.5 μg/kg in distilled water, 1.4–17.3 μg/kg in 3% acetic acid, 1.4–19.2 μg/kg in 10% alcohol, and 31.9–390.8 μg/kg in olive oil. The RSDs were in the range of 0.07–11.28%. The real plastic products inspection showed that only few analyzed samples were phthalates contaminated. Bis‐2‐ethylhexyl ester and dibutyl phthalate were the common items migrated from the plastic products into food and feeds, but the migration concentrations were far below the limits set by European Union (1.5 mg/kg for bis‐2‐ethylhexyl ester and 0.3 mg/kg for dibutyl phthalate).     

Determination of Pyromellitic Acid in Aqueous Matrices by CE

An analytical method for the capillary electrophoresis determination of pyromellitic acid in aqueous media used as “food simulants” has been developed and is described in this paper. The proposed method determined the pyromellitic acid at ppb levels and is based on a capillary zone electrophoresis separation using coated fused-silica capillary column with a carbonate running buffer and a UV-Vis detector. The method herein developed has been applied to the determination of pyromelitic acid residues leached from plastic bottles. The amount of pyromellitic acid determined in different batch of polyethyleneterephthalate bottles is 2.18%, while the limit of detection is 2.30 ng mL^?1 with a relative standard deviation of 4.40%.     

Application of capillary electrophoresis in migration studies of food contact materials – part 1: Substituted phenolic additives

A method has been developed to determine 11 phenolic antioxidants in the food simulants distilled water, 3% acetie acid, and 15% ethanol, using; micellar capillary electrophoresis (MCE). All the phenols could he analyzed within 35 min. The analytical recovery from spiked simulants was 80 to 119% except for 2,6-di-tert-butyl-4hydroxytoluenc (BHT) and octyl gallate, which could not be recovered from 3% acetic acid simulant. Calibration graph correlation coefficients for the 11 phenols were 0.982 to 0.999. Limits of detection (LoDs) were from 2.8 to 8.6 mg/L. These LoDs are well below European Union migration limits for these substances. It is concluded therefore that MCE offers a rapid and reliable analysis for the control of migration from plastics intended for food contact which employ these phenols as antioxidants.     

A novel method for the determination of migration of contaminants from food contact materials

A neutron activation method has been developed for the analysis of high density polyethylene, low density polyethylene, polypropylene, polyethylene terephthalate and polystyrene food contact plastics. The method provides determination of over 50 elements at concentrations below 1 mg kg^–1. This technique has now been extended to study migration from food contact materials into standard food simulants (olive oil, acetic acid, ethanol and water). Samples of plastic are irradiated in a thermal neutron flux to produce radionuclides of the elements present in the plastic. Over a period of time the radionuclides of these elements may travel from the plastic into the food simulants, and hence the migration can be determined. Gamma ray spectrometry is performed on the simulants at the end of the test to quantify the migration. Any activity present must be due only to the migration of radionuclides of elements in the plastic and nothing else. This eliminates the need for a blank determination, which is required with existing migration methods. Preliminary studies have shown that detection limits of around 0.002 mg kg^–1 can be achieved for Sb in a retail polyethylene terephthalate (PET) bottle. This can be compared to levels of 0.005     

高效液相色谱-串联质谱法快速测定水基食品模拟物中28种受限芳香族伯胺的迁移量

建立了高效液相色谱-串联质谱(HPLC-MS/MS)联用方法用于快速测定水基食品模拟物(10%乙醇、30 g/L乙酸和20%乙醇)中28种芳香族伯胺的迁移量。用水基食品模拟物浸泡待测样品中一定时间(在100 ℃条件下)后,冷却至室温并混匀,所得浸泡液经亲水性聚四氟乙烯针头式过滤器过滤后,直接进行HPLC-MS/MS测定。采用Agilent Zorbax SB-Phenyl柱,以水和0.1%甲酸-25%乙腈-甲醇溶液为流动相进行梯度洗脱分离;质谱具电喷雾离子源,在正离子和分段式多反应监测(MRM)模式下检测。结果表明,方法定量限为0.002～10 μg/L,在5～100 μg/L或10～100 μg/L范围内线性关系良好(r2＞0.995);在10、20、40 μg/L水平的加标回收率为76.6%～114%,相对标准偏差为1.53%～8.97%。该方法样品前处理简单快速,色谱分离效果和线性关系好,检出限较低、回收率和准确度高,且完全满足欧盟(EU)No 10/2011法规中对芳香族伯胺特定迁移量的限量要求。该方法已成功应用于30批次出口欧盟的食品接触材料相关制品中芳香族伯胺特定迁移量的检测。     

Application of single-drop microextraction to the determination of dialkyl phthalate esters in food simulants

A fast and simple method, using static single-drop microextraction (SDME), has been developed to facilitate the identification and quantification of seven dialkyl phthalate esters in the three aqueous food simulants. The simulants were: A, distilled water; B, 3% (w/v) acetic acid/water; and C, 15% (v/v) ethanol/water. The extraction is performed by simply suspending a drop of organic solvent in the aqueous sample using a conventional gas chromatography (GC) microsyringe. Following extraction, the organic phase is withdrawn into the syringe and analyzed by gas chromatography and flame ionization detection (FID). The optimized method yields a linear calibration curve over three orders of magnitude for all the simulants, and method detection limits (MDLs) allowing detection of all the studied compounds at concentrations below migration limits established by the European Union. The accuracy of the SDME method was tested and compared to that of solid-phase microextraction (SPME) by recovery experiments using spiked samples, with results ranging from 85 to 115% in most cases.     

Determination of Dihydroxybenzenes in Plastic Food Packaging Materials and in Food Simulating Liquids Using Capillary Electrophoresis

A capillary electrophoresis method has been developed to determine 1,2-dihydroxybenzene and 1,3-dihydroxybenzene in the food simulants distilled water, 3% acetic acid, 15% ethanol, and olive oil. Both substances, used as monomers and additives to make food packaging plastics, could be analyzed within 15 min. The 1,4-dihydroxybenzene isomer was unretained and eluted with the electroosmotic flow, and so the CE method can give only a semi-quantitative estimate of this isomer if it is present as a migrant. The analytical recovery for the 1,2- and 1,3-isomers from spiked simulants was good at 87% to 98% except for 1,2-dihydroxybenzene which could only be recovered to the extent of 58% from olive oil. Calibration graphs were linear and the limit of detection for each substance was 0.6 mg/kg, which is well below migration limits for these substances. It is concluded that CE offers a rapid and reliable analysis for the control of migration from plastics intended for food contact which employ 1,2-dihydroxybenzene or 1,3-dihydroxybenzene during manufacture, and offers a screening method for 1,4-dihydroxybenzene migration.     

Assessment of specific migration to aqueous simulants of a new active food packaging containing essential oils by means of an automatic multiple dynamic hollow fibre liquid phase microextraction system

The determination of specific migration in the three aqueous food simulants (water, 3% acetic acid and 10% ethanol) from experimental active packaging polypropylene-based films containing natural essential oils as active agents has been carried out for the first time by a two-phase hollow fibre liquid phase microextraction (HFLPME). Due to the high number of variables involved, an experimental design has been applied. High throughput, with six samples running simultaneously in a highly automated system working in dynamic extraction mode, has been achieved. The main analytical characteristics are detection limits as low as 0.01 μg kg⁻¹, linearity higher than 0.99 for almost 5 magnitude orders, average precision below 16% as RSD and concentration factors ranging from 4 to 189. Migration of 43 compounds including terpenes, alkanes, plastic additives and degradation compounds is reported. According to the results obtained and European legislation, the packaging prototypes tested could be safely marketed.     

Gas-chromatographic determination of formic acid in the oxidation products of organic substances

Procedures for the gas-chromatographic determination of formic acid in oxidation produts of organic substances after its conversion to benzyl formate were developed. In determining formic acid in an organic phase, free formic acid was esterified with benzyl alcohol in a pyridine solution while adding acetic anhydride under mild conditions. The conversion of formic acid was complete even in the presence of other mono-and dicarboxylic acids in considerable amounts. It was found that the formation of benzyl formate occurred via a mixed aldehyde formed in situ from formic acid and acetic anhydride. The determination of formic acid in aqueous solutions involves the synthesis of its sodium or potassium salt and the successive treatment of this salt with acetyl chloride and benzyl alcohol in a pyridine solution.     

Analysis of Morpholinium Ionic Liquid Cations by Hydrophilic Interaction Columns Coupled with Indirect UV Detection

A method was developed for the separation and detection of morpholinium ionic liquid cations by hydrophilic interaction column combined with indirect ultraviolet detection using imidazolium ionic liquids as ultraviolet absorbents in high‐performance liquid chromatography. The effects of the ultraviolet absorbents, organic solvents, and the pH value of the aqueous solution in the mobile phase for the determination of morpholinium cations were investigated by using a hydrophilic column with carbamoyl group as the analytical column. The retention and detection behavior of morpholinium cations was discussed. The suitable chromatographic conditions were 0.8 mmol/L 1‐ethyl‐3‐methyl‐imidazolium tetrafluoroborate aqueous solution (pH 3.5 adjusted with acetic acid)/acetonitrile (45/55, v/v) as the mobile phase and a detection wavelength of 210 nm. Under these conditions, the baseline separation of N‐methyl‐N‐ethyl‐morpholinium cation ([MEMo]⁺) and N‐methyl‐N‐propyl‐morpholinium cation ([MPMo]⁺) was successfully achieved in 15 min. The detection limits of [MEMo]⁺ and [MPMo]⁺ were 0.595 and 0.531 mg/L, respectively. Relative standard deviations were less than 0.2%. This method has been successfully applied to the analysis of morpholinium ionic liquid samples synthesized in chemical laboratories, which is simple, reliable, and practical.     

A novel method for the estimation of arsenic(V) in organic compounds

A novel method for the determination of arsenic(V) in organic compounds has been developed by reducing combined arsenic(V) to arsenic(III) in aqueous acetic acid medium with zinc dust. In some cases, addition of ethyl alcohol is necessary to dissolve the compound and to keep the arsenic(III) compound in solution. The arsenic(III) is titrated with iodine and the end-point is detected visually with starch as indicator or potentiometrically.     

Kinetics of the hydrolysis of bisphenol A diglycidyl ether (BADGE) in water-based food simulants

Summary The first-order degradation kinetics of bisphenol A diglycidyl ether (BADGE; CAS No. 1675-54-3) has been studied in three water-based food simulants (3% (W/V) acetic acid, distilled water and 15% (V/V) ethanol) at various temperatures. BADGE and its first and second hydrolysis products were determined by reversed-phase high-performance liquid chromatography with fluorescence detection. Nonlinear regression was used to fit the experimental data at 40, 50 and 60°C with the proposed kinetic equations; Arrhenius' equation was then fitted to the rate constants obtained and the kinetic models were tested by comparing experimental data obtained at 70°C with the kinetic curves calculated using the rate constants predicted for this temperature. The half-life of BADGE was longest in ethanol and shortest in acetic acid. The rings opening in acetic acid appears to happen by means of active hydrogens whereas in the other simulants it is mainly influenced by the formation of acid/base adducts. The results imply that resins which comply with existing legislation on the migration of unreacted monomer may still contaminate foodstuffs.     

乙醇对砷锑钼蓝测砷法的增敏作用研究及其应用

本文提出了一个利用乙醇的增敏作用,进行砷锑钼蓝测定痕量砷的高灵敏度的分析方法,对水中砷的检出限可达18ppt。通过对水、植物和钢铁中砷的分析,证明本方法具有较好的实用价值。对有机试剂的增敏作用进行了初步讨论。     

Specific determination of 20 primary aromatic amines in aqueous food simulants by liquid chromatography-electrospray ionization-tandem mass spectrometry

A multi-analyte method without any pre-treatment steps using reversed-phase liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) was developed and applied for the determination of 20 primary aromatic amines (PAA) associated with polyurethane (PUR) products or azo-colours. The method was validated in-house for water and 3% acetic acid food simulants using spiked migrates from plastic laminates. Detection limits ranged from 0.27 to 3 microg amine/L food simulants, and RSD values of within-laboratory reproducibility at the 2 microg PAA/L level ranged from 3.9 to 19%. PAA migration from plastic laminates and black nylon cooking utensils were determined with the method, and high levels of 4,4'-methylenedianiline and aniline were found in migrates from about half of the tested cooking utensils. The method fulfils present legislative demands in the EU for screening and verification of PAA migration from food contact materials.     

FTIR investigation of the specific migration of additives from rigid poly(vinyl chloride)

Commercial sunflower oil was epoxidized and used as organic costabiliser for rigid poly (vinyl chloride) (PVC) containing zinc and calcium stearates as primary stabilisers and stearic acid as lubricant. For applications in the packaging of foodstuffs, migration testing must be realised. For that purpose, two food simulants were used (sunflower oil and 15% (v/v) aqueous ethanol). The test conditions were 12 days at 40 °C. Circular samples of rigid PVC were immersed in a well known volume of food simulant. A circular sample and 10 ml of food simulant were taken off every day to be analysed. The specific migrations of the additives were investigated by using Fourier transform infrared spectroscopy.The direct analysis of the food simulants was difficult because overlapping of the bands of the additives. However, the analysis of PVC films obtained by dissolution of the circular samples in tetrahydrofuran and evaporation of the solvent was more conclusive. The specific migrations of the metal carboxylates and epoxidized sunflower oil were evidenced.     

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.