Extraction and analysis of an organophosphate salt nucleating agent from irradiated polypropylene resin.

Although it is well-established that irradiation of produce can reduce food-borne pathogens and spoilage organisms, data on the effect of irradiation on polymer additives in food packaging materials are limited, particularly for those additives used in packaging leafy greens or in current food packaging materials. We investigated the effects of irradiating a nucleating agent, aluminium, hydroxybis[2,4,8,10-tetrakis(1,1-dimethylethyl)-6-hydroxy-12H-dibenzo [d,g][1,3,2]dioxaphosphocin 6-oxidato]- (CAS Reg. No. 151841-65-5), at doses of 1-20 kGy in polypropylene. That nucleating agent was then extracted using accelerated solvent extraction and analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS), liquid chromatography-photodiode array detection (LC-PDA), and solid-state nuclear magnetic resonance (SSNMR) spectroscopy. We found this nucleating agent was not significantly affected by radiation treatment up to 20 kGy. Therefore, this nucleating agent could potentially be useful in food packaging materials that will be irradiated at doses of 20 kGy or less. Establishing which additives are stable under anticipated irradiation doses will help support safety evaluation of food packaging materials.

Determination of phthalate concentrations in paper-based fast food packaging available on the U.S. market.

Phthalates are one of many chemical compounds that are used as plasticisers. Packaging can transfer plasticisers to the surfaces of foods or other materials. A recent study suggested a link between fast food consumption and increased urine phthalate metabolites even though phthalates are most commonly found in food contact materials made of PVC while fast food packaging is most commonly composed of paper and paper board. Phthalates in PVC are usually present in percent concentrations. In non-PVC food contact materials, such as paper or paperboard, the concentrations, if any, are expected to be significantly lower which can greatly impact the analytical method used for their determination. Due to the widespread use of plasticised PVC in many commercial applications, background concentrations of phthalates are a concern for trace concentration analyses and background contamination must be avoided when performing these analyses. A glassware cleaning method was developed and a solvent extraction with dichloromethane and hexane was used to extract phthalates from paper-based food packaging. The extracts were then analysed using a GC-MS/MS. The minimum reporting concentrations for the method were determined to be 0.10-0.40 µg/g depending on the phthalate investigated. Phthalate concentrations in several different non-PVC printed and unprinted packaging are presented. Of the 54 packaging samples tested, 10 samples contained no reportable concentrations of any of the 6 phthalates investigated. Of those that were reportable, all measured lower than 10 µg/g and in fact, most had concentrations less than 1 µg/g. These data demonstrate that phthalates from fast food packaging do not significantly contribute to overall consumer exposure.

Migration of phenolic brominated flame retardants from contaminated food contact articles into food simulants and foods.

Several food contact articles (FCAs) contaminated with unapproved brominated flame retardants (BFRs) purchased in the US market were analysed and subjected to migration tests. Migration tests were performed in food simulants (water, 3% acetic acid, 10% ethanol and 50% ethanol) and food (milk, coffee and chicken bouillon soup) to evaluate the BFRs mass transfer from the contaminated FCA. The BFRs studied, 2,4,6-tribromophenol (TBP), 3,3',5,5'-tetrabromobisphenol A (TBBPA), and 1,2,5,6,9,10-hexabromocyclododecane (HBCD) were analysed by UHPLC-MS/MS. The method validation parameters were r2 ≥ 0.999, LOD ≤ 0.3 ng mL-1, and RSD ≤ 1.7 % (n = 7). HBCD was not stable under our migration conditions and was not detected in any FCA, food or food simulant, including positive controls. Phenolic BFRs (TBP and TBBPA) migrated at concentrations ranging from non-detected to 73 µg kg-1 in food simulants, and from 1 to 23 µg kg-1 in food. Phenolic BFRs migrated into 50% ethanol food simulant at higher concentrations than in more aqueous food simulants and foods.

Rapid identification of polyamides using direct analysis in real time mass spectrometry.

RATIONALE: Polyamide (PA) is the generic name of polymers synthesized by linking monomers via amide bonds, and various types of PAs with different monomer compositions are known. Distinguishing PA polymers is useful in directing monomer residual testing, product testing, and reverse engineering, but is analytically challenging and cumbersome. To simplify this, we explored the applicability of direct analysis in real time mass spectrometry (DART-MS) for screening PA polymers. METHODS: A DART ion source coupled to a quadrupole Orbitrap (high-resolution (HR) mass spectrometer) was employed for this study. Ten types of PA polymers and four retail samples were evaluated. The DART-HRMS data for these samples, as well as the DART-MS/MS (MS2 ) data for PA6 and PA66, were obtained, and their repeatability was assessed across days/calibrations, operators, and equipments. RESULTS: Ions corresponding to the cyclic or linear monomers and oligomers of each PA polymer were detected in each DART-HR mass spectrum. Although similar DART-HR mass spectra were obtained for PA6, PA66, and PA6/PA66 (polymer blends of PA6 and PA66), their DART tandem mass spectra were completely different. The analysis was repeatable, and nearly identical DART tandem mass spectra were obtained on different days, by different operators, and with different equipment. This technique was successfully applied to commercially available samples. CONCLUSIONS: Ten types of PA polymers were distinguished using DART-HRMS and DART-MS2 , and their identification using these techniques was straightforward as the characteristic ions for each PA polymer were identified and detected. Furthermore, the spectra were obtained rapidly. Therefore, DART-HRMS can be considered an efficient screening technique for the rapid identification and differentiation of PA polymers.

Assessment of the Impact of Accelerated Migration Testing for Coated Food Cans Using Food Simulants.

In this study, an accelerated migration test on food can coatings into food simulants was investigated. Food simulants covering a wide range of polarity were used to conduct migration tests at 60 °C with storage times ranging from 4 h to 30 days. Epoxy-resins, acrylic-phenolic, polyester, and vinyl coatings were exposed to water, 3% acetic acid, 50% ethanol, and Miglyol 812®. Using liquid chromatography coupled to a variety of detectors (UHPLC-Q-Orbitrap-MS, UFLC-MS/MS, and HPLC-DAD), migration of several monomers and previously identified oligomers, as well as some unidentified migrants, were determined during the experiment. The data from this study was compared to our findings from previous long-term migration studies with storage times ranging from 24 h to 540 days at 40 °C using the same can coating applications. The results illustrate that performing migration experiments for short time periods at 60 °C may mimic migration results that would be obtained at 40 °C after long-term migration tests (up to 1.5 years) from food can coatings into food simulants.

Investigation of the primary plasticisers present in polyvinyl chloride (PVC) products currently authorised as food contact materials.

PVC is a common food contact material that is usually plasticised to increase its flexibility. Phthalates are one class of chemical compounds that are often used as plasticisers in PVC in a wide range of industries. They may be used in packaging materials for foods and can also be found in components of certain food processing equipment such as conveyor belts and tubing. Transfer of plasticisers from packaging to foods can occur. In recent years, there has been increased interest in understanding the health effects of phthalates, as well as the possible human exposure levels. However, there is limited information available about the routes of exposure to phthalates. In July 2014, the Chronic Hazard Advisory Panel (CHAP) produced a report for the U.S. Consumer Product Safety Commission detailing the potential health hazards of phthalates and phthalate alternatives. This report listed diet as one factor contributing greater than or equal to 10% of total phthalate exposure. As a result of this report, the U.S. Food and Drug Administration (FDA) is interested in determining the types of the primary plasticiser present in food packaging and processing materials as well as their concentrations. An investigation was conducted of 56 different samples of PVC food packaging and food processing materials available in the US market using a solvent extraction and GC-MS analysis. Nine different plasticisers including three phthalates, di(2-ethylhexyl) phthalate, diisononyl phthalate and diisodecyl phthalate, were identified in the products tested. The plasticiser concentrations ranged from 1 to 53% depending on the types of food contact materials and the type of plasticiser. Overall, it appears that manufacturers are switching away from phthalates as their primary plasticiser to alternate compounds such as ESBO, ATBC, DEHT, DINCH, DEHA and DINA.

Evaluation of Short-Term and Long-Term Migration Testing from Can Coatings into Food Simulants: Epoxy and Acrylic-Phenolic Coatings.

Traditionally, migration testing during 10 days at 40 °C has been considered sufficient and appropriate for simulating the potential migration of substances from food-contact materials into foods. However, some packages, such as food cans, may be stored holding food for extended time periods (years). This study attempts to verify whether common testing conditions accurately estimate long-term migration. Two types of can coatings, epoxy and acrylic-phenolic, were subjected to short-term and long-term migration testing (1 day-1.5 years) using food simulants (water, 3% acetic acid, 50% ethanol, and isooctane) at 40 °C. Using HPLC-DAD/CAD, HPLC-MS, UHPLC-HRMS (where HRMS is accurate mass, mass spectrometry), and DART-HRMS, we identified potential migrants before starting the experiment: BPA, BADGE, BADGE derivatives, benzoguanamine, and other relevant marker compounds. During the experiment using a water-based food simulant, migrants remained stable. Most of the cans in contact with 3% acetic acid did not survive the experimental conditions. Tracked migrants were not detected in isooctane. In the presence of 50% ethanol, the traditional migration test during 10 days at 40 °C did not predict migration during long-term storage. These results suggest that migration protocols should be modified to account for long-term storage.

A Collaborative Study: Determination of Mycotoxins in Corn, Peanut Butter, and Wheat Flour Using Stable Isotope Dilution Assay (SIDA) and Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS).

A collaborative study was conducted to evaluate stable isotope dilution assay (SIDA) and LC-MS/MS for the simultaneous determination of aflatoxins B1, B2, G1, and G2; deoxynivalenol; fumonisins B1, B2, and B3; ochratoxin A; HT-2 toxin; T-2 toxin; and zearalenone in foods. Samples were fortified with 12 13C uniformly labeled mycotoxins (13C-IS) corresponding to the native mycotoxins and extracted with acetonitrile/water (50:50 v/v), followed by centrifugation, filtration, and LC-MS/MS analysis. In addition to certified reference materials, the six participating laboratories analyzed corn, peanut butter, and wheat flour fortified with the 12 mycotoxins at concentrations ranging from 1.0 to 1000 ng/g. Using their available LC-MS/MS platform, each laboratory developed in-house instrumental conditions for analysis. The majority of recoveries ranged from 80 to 120% with relative standard derivations (RSDs) <20%. Greater than 90% of the average recoveries of the participating laboratories were in the range of 90-110%, with repeatability RSDr (within laboratory) < 10% and reproducibility RSDR (among laboratory) < 15%. All Z scores of the results of certified reference materials were between -2 and 2. Using 13C-IS eliminated the need for matrix-matched calibration standards for quantitation, simplified sample preparation, and achieved simultaneous identification and quantitation of multiple mycotoxins in a simple LC-MS/MS procedure.

Identification of unknown compounds from polyester cans coatings that may potentially migrate into food or food simulants.

Cross-linked polyester resins are being introduced into the market as alternatives to epoxy resins as coatings for metal food cans. Identification of potential migrants, from these coatings into food, is a significant analytical challenge due to the diversity of substances employed in the manufacture of the coatings. However, such identification is required to assess migration from the can coating into the food and quantify dietary exposure. Polyester can coatings were extracted with acetonitrile at 40°C for 24h and the extracts were analyzed by a variety of analytical techniques, including GC-MS, HPLC-DAD/MS, HPLC-DAD/CAD and UHPL C-HRMS. Twenty nine non-volatile oligomers were tentatively identified using retention times, UV spectra, and accurate mass measurements. Identified oligomers suggest the coating in use for food cans is a polyester coating and is mainly based on the monomers isophthalic acid, terephthalic acid and nadic acid. To give confidence in the identification, one of the tentatively identified oligomer was synthetized and analyzed by (13)C and (1)H NMR and UHPL C-HRMS. The NMR and HRMS results, confirmed the presence of this compound in the can extracts. Finally, to determine if rapid, direct detection of the oligomers was practical, the coatings were analyzed by DART-HRMS. Twenty three out of the 29 oligomers were identified in the coating by direct measurement with DART-HRMS in few minutes.

Evaluation of Long-Term Migration Testing from Can Coatings into Food Simulants: Polyester Coatings.

FDA guidance for food contact substances recommends that for food packaging intended for use at sterilized, high temperature processed, or retorted conditions, a migration test with a retort step at 121 °C for 2 h followed by a 10 day migration test at 40 °C should be performed. These conditions are in intended to simulate processing and long-term storage. However, can coatings may be in contact with food for years, and there are very few data evaluating if this short-term testing accurately simulates migration over extended time periods. A long-term migration test at 40 °C with retorted and non-retorted polyester cans using several food simulants (water, 3% acetic acid, 10% ethanol, 50% ethanol, and isooctane) was conducted to verify whether traditional migration testing protocols accurately predict migration from food contact materials used for extended time periods. Time points were from 1 day to 515 days. HPLC-MS/MS was used to analyze polyester monomers, and oligomer migration was monitored using HPLC-DAD/CAD and HPLC-MS. Concentrations of monomers and oligomers increased during the migration experiments, especially in ethanol food simulants. The data suggest that current FDA migration protocols may need to be modified to address changes in migrants as a result of long-term storage conditions.

Target and non-target analysis of migrants from PVC-coated cans using UHPLC-Q-Orbitrap MS: evaluation of long-term migration testing.

A simple, rapid and sensitive method for analyzing multi-target and non-target additives in polyvinyl chloride (PVC) food can coatings using ultra-high-performance liquid chromatography coupled to quadrupole-orbital ion-trap mass spectrometry was developed. This procedure was used to study the behaviour of a cross-linking agent, benzoguanamine (BGA), two slip agents, oleamide and erucamide, and 18 other commonly used plasticisers including phthalates, adipates, sebacates, acetyl tributyl citrate and epoxidised soybean or linseed oils. This optimised method was used to detect these analytes in food simulants (water and 3% acetic acid) in a long-term migration test of PVC-coated food cans for a period ranging from 1 day to 1.5 years at 40°C. Although very low detection limits (5 ng ml(-1)) were obtained for the majority of compounds, none of the monitored plasticisers and slip agents was detected in simulants extracted from cans over the period of the test. However, the presence of BGA in both aqueous food simulants was confirmed based on high-resolution mass spectrometry, product ion spectra and analysis of a reference standard. The BGA concentration in both simulants continued to increase with storage time: after 1.5 years storage in aqueous food simulants at 40°C, BGA was detected at concentrations up to 84 µg dm(-2). We believe this is the first study describing the long-term migration capacity of BGA from any vinyl coating material intended for use in PVC-coated food cans. Our results may have implications for migration test protocols for food cans that will be stored for extended time periods.

Characterisation and potential migration of silver nanoparticles from commercially available polymeric food contact materials.

The potential for consumer exposure to nano-components in food contact materials (FCMs) is dependent on the migration of nanomaterials into food. Therefore, characterising the physico-chemical properties and potential for migration of constituents is an important step in assessing the safety of FCMs. A number of commercially available food storage products, purchased domestically within the United States and internationally, that claim to contain nanosilver were evaluated. The products were made of polyethylene, polypropylene and polyphenylene ether sulfone and all contained silver (0.001-36 mg kg(-1) of polymer). Silver migration was measured under various conditions, including using 3% acetic acid and water as food simulants. Low concentrations (sub-ppb levels) of silver were detected in the migration studies generally following a trend characterised by a surface desorption phenomenon, where the majority of the silver migration occurred in the first of three consecutive exposures. Silver nanoparticles were not detected in food simulants, suggesting that the silver migration may be due solely to ionic silver released into solution from oxidation of the silver nanoparticle surface. The absence of detectable silver nanoparticles was consistent with expectations from a physico-chemical view point. For the products tested, current USFDA guidance for evaluating migration from FCMs was applicable.

A novel method for the simultaneous determination of 14 sweeteners of regulatory interest using UHPLC-MS/MS.

An improved, efficient, sensitive method for the determination of 14 non-nutritive sweeteners in food products was developed using electrospray ionisation (ESI) ultra-high-performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) in the negative-ion mode. Fourteen sweeteners and three internal standards were separated on a reversed-phase UHPLC column using a simple gradient programme. Analyte quantitation and confirmation were performed with data collection in multiple reaction monitoring (MRM) mode. Limits of detection (LODs) were determined in a representative drink, candy and yogurt sample and ranged from 0.1 to 1.8 ng ml(-1) (drinks) and from 0.1 to 2.5 ng g(-1) (candy and yogurt). Repeatability at the limit of quantitation (LOQ) ranged from 1% to 13% relative standard deviation (RSD). Twenty-seven commercially available food products were tested using the optimised method showing that the majority of products contained sweetener concentrations below their assigned maximum usable dose. Recovery studies were performed and accuracy data are presented.

Liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the direct detection of 2-monochloropropanediol (2-MCPD) esters in edible oils.

A new analytical method has been developed and validated for the detection and quantification of 2-monochloropropanediol (2-MCPD) esters in edible oils. The target compounds are potentially carcinogenic contaminants formed during the processing of edible oils. As the 2-MCPD esters that occur most frequently in refined edible oils were not commercially available, standards were synthesized with identity and purity (95+%) confirmed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and (1)H NMR. Target analytes are separated from edible oil matrices using a two-step solid-phase extraction (SPE) procedure. The extracts are then analyzed using LC-MS/MS with electrospray ionization (ESI). The method has been validated for 11 2-MCPD diesters and 3 2-MCPD monoesters in soybean oil, olive oil, and palm oil using an external calibration curve. The ranges of average recoveries and relative standard deviations (RSD) across the three oil matrices at three spiking concentrations are 79-106% (3-13% RSD) for the 2-MCPD diesters and 72-108% (4-17% RSD) for the 2-MCPD monoesters, with limits of quantitation at or below 30 ng/g for the diesters and 90 ng/g for the monoesters.

Screening multimycotoxins in food-grade gums by stable isotope dilution and liquid chromatography/tandem mass spectrometry.

Stable isotope dilution with LC/MSIMS was used to determine the following 11 mycotoxins in food grade gums: aflatoxins B1, B2, G1, and G2; deoxynivalenol; fumonisins B1, B2, and B3; ochratoxin A; T-2 toxin; and zearalenone. Samples were fortified with 11 [13C]-uniformly labeled internal standard ([13C]-IS) mycotoxins that corresponded to the 11 target mycotoxins and extracted by acetonitrile-water (4 + 1, v/v), followed by LC/MS/MS analysis. Mycotoxins were quantitated with the fortified [13C]-IS in each sample. The average recoveries of aflatoxins B1, B2, G1, and G2 (1, 5, and 25 microg/kg); deoxynivalenol and fumonisins B1, B2, and B3 (25, 100, and 500 microg/kg); and ochratoxin A, T-2 toxin, and zearalenone (10, 50, and 250 microg/kg) ranged from 84 to 117% with RSDs less than 20%. Method-dependent LOQs were from 0.1 (aflatoxin B1) to 25 microg/kg (fumonisin B3). Among 20 market samples, aflatoxin B1 (< LOQ) was detected in a Guar gum and a Tragacanth gum, and zearalenone (6 +/- 0.6 microg/kg) was detected in a Xanthan gum. The detected mycotoxins were further confirmed by comparing their enhanced product ion spectra to those of reference standards. The single laboratory validated stable isotope dilution and LC/MSIMS method provides sufficient selectivity, sensitivity, accuracy, and reproducibility with a simple sample preparation to screen the 11 mycotoxins in gums.

Single-laboratory validation of a method for the determination of select volatile organic compounds in foods by using vacuum distillation with gas chromatography/mass spectrometry.

Recent studies showed that headspace and purge and trap methods have limitations when used to determine volatile organic compounds (VOCs) in foods, including matrix effects and artifact formation from precursors present in the sample matrix or from thermal decomposition. U.S. Environmental Protection Agency Method 8261A liberates VOCs from the sample matrix by using vacuum distillation at room temperature. The method was modified and validated for the determination of furan, chloroform, benzene, trichloroethene, toluene, and sytrene in infant formula, canned tuna (in water), peanut butter, and an orange beverage (orange-flavored noncarbonated beverage). The validation studies showed that the LOQ values ranged from 0.05 ng/g toluene in infant formula to 5.10 ng/g toluene in peanut butter. Fortified recoveries were determined at the first, second, and third standard additions, and concentrations ranged from 0.07 to 6.9 ng/g. When quantified by the method of standard additions, the recoveries ranged from 56 to 218% at the first standard addition and 89 to 117% at the third. The validated method was used to conduct a survey of the targeted VOCs in 18 foods. The amounts found ranged from none detected to 73.8 ng/g furan in sweet potato baby food.

Development and single-laboratory validation of an improved method for the determination of cyclamate in foods using liquid chromatography/tandem mass spectrometry.

A fast and reliable LC-MS/MS method for the determination of cyclamate in a variety of food matrices was developed and validated. This method provides both quantitation and qualitative mass spectral determination important for analysis of regulatory samples. Utilization of a cyclamate-d11 internal standard corrects for potential matrix interferences during sample injection and allows minimal sample preparation. Seventeen commercially available food products were fortified at 250 µg/mL and tested as part of the method validation. Recoveries ranged from 72to 110%, with RSDs ranging from 3 to 15%. The linear range spanned 0.010-1.00 µg/mL. LODs were 0.1 and 0.6 ng/mL, determined in pomegranate juice and dried fig, respectively. LOQs were 0.3 and 1.6 ng/mL, which are significantly lower than needed to measure cyclamate when used as a food additive. The interday and intraday accuracy and precision data are presented. This method was validated for analysis of a variety of commonly adulterated products, including drinks, dried fruits, jams, and hard candies.

Application of single immunoaffinity clean-up for simultaneous determination of regulated mycotoxins in cereals and nuts.

A rapid and sensitive analytical strategy for the simultaneous determination of twelve mycotoxins (aflatoxins, fumonisins, zearalenon, deoxynivalenol, ochratoxin A, T-2 and HT-2 toxins) using ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS) was developed and validated. The method was validated for peanuts, barley and maize-breakfast cereals; selected as they represent the matrices most often contaminated by mycotoxins. The method is designed for fast and reliable analyses of mycotoxins in regulatory, industrial and private laboratories. Multi-target immunoaffinity columns containing antibodies for all mycotoxins studied herein were used for sample clean-up. Method optimization was predominantly focused on the simplification of extraction and clean-up procedure recommended by column producers. This newly developed and simplified procedure decreased both the sample preparation time and the solvent volumes used for their processing. The analysis of all regulated mycotoxins was conducted by a newly developed UHPLC-MS/MS method with a sample run time of only ten minutes. The method trueness was tested with analytical spikes and certified reference materials, with recoveries ranging from 71% to 112% for all of the examined mycotoxins.

Occurrence of 3-MCPD and glycidyl esters in edible oils in the United States.

Fatty acid esters of 3-monochloropropanediol (3-MCPD) and glycidol are processing contaminants found in a wide range of edible oils. While both 3 MCPD and glycidol have toxicological properties that at present has concerns for food safety, the published occurrence data are limited. Occurrence information is presented for the concentrations of 3-MCPD and glycidyl esters in 116 retail and/or industrial edible oils and fats using LC-MS/MS analysis of intact esters. The concentrations for bound 3-MCPD ranged from below the limit of quantitation (

Determination of perfluorochemicals in fish and shellfish using liquid chromatography-tandem mass spectrometry.

This paper reports the validation and application of a method for determination of 10 perfluorochemicals (PFCs) in retail fish and shellfish. The analytes of interest were 7 perfluorinated carboxylates and 3 perfluorinated sulfonates. Fish and shellfish samples were digested with a basic solution of 10 mM sodium hydroxide in methanol before sonication and solid phase extraction through weak anion exchange. Analysis was performed using liquid chromatography-tandem mass spectrometry. Recoveries from spiking five different types of fish and shellfish indicate that the method performs similarly with different fish types, and recoveries were over 90% for all analytes. Forty-six retail samples, collected between 2010 and 2012, including 13 different types of fish and shellfish were analyzed for PFCs. The 13 different types included the top 10 most-consumed fish and shellfish in the United States according to data collected by the National Fisheries Institute. Two Standard Reference Materials were also analyzed. Most fish and shellfish had no detected PFCs; only 11 samples of the 46 tested had detectable concentrations of PFCs.