Se-Jong Park

Release of N-nitrosamines and N-nitrosatable substances from baby bottle teats and rubber kitchen tools in Korea

AbstractnEnsuring the safety of baby bottle teats and kitchen tools made from rubber is critical. Therefore, the migration of N-nitrosamines and N-nitrosatable substances from 30 teats and 45 kitchen tools to artificial saliva was analyzed by liquid chromatography–tandem mass spectrometry. The method was validated by assessing the limits of detection (0.46–3.87xa0μg/kg), limits of quantification (1.38–11.73xa0μg/kg), and recoveries (86.3–108.6%) of seven compounds. Nitrosodimethylamine (NDMA), N-nitrosopiperidine, and N-nitrosomorpholine (NMOR) migrated from baby bottle teats at concentrations of not detected (ND) to 3.67xa0μg/kg. NDMA and NMOR concentrations ranged from ND to 1.72xa0μg/kg after migration from 45 rubber kitchen tools. N-nitrosatable substances ranged from ND to 42.16xa0μg/kg after migration from baby bottle teats but did not migrate from rubber kitchen tools. All tested products were considered safe for use, as N-nitrosamine and N-nitrosatable substance levels did not exceed the permitted management specifications.

Simultaneous analysis and exposure assessment of migrated bisphenol analogues, phenol, and p-tert-butylphenol from food contact materials

ABSTRACT A simple, rapid, and novel liquid chromatography tandem-mass spectrometry (LC-MS/MS) method was developed and validated to determine levels of eight bisphenol analogues (A, S, F, B, P, AF, AP, and Z), phenol, and p-tert-butylphenol migrated from food contact material (FCM) into food simulants. Method validation showed acceptable values in terms of linearity, precision, and accuracy. The limits of detection and quantification were 0.53–29.6 and 1.77–29.6 μg L−1, respectively. Water, 4% acetic acid, 50% ethanol, and n-heptane were employed as food simulants for the migration tests, and the proposed method was applied to 234 articles of 11 FCMs including polycarbonate, polyethersulfone, polypropylene, and polyethyleneterephthalate, obtained from domestic markets and manufacturers in Korea. Only phenol was found in the FCMs poly(cyclophexane-1,4-dimethylene terephthalate), polylactide, and thermoplastic polyurethane. Eight bisphenol analogues and p-tert-butyl phenol were not found in any samples. Using the obtained migration results, the estimated daily intake (EDI) of phenol was calculated. Exposure assessments were carried out to compare the EDI with the tolerable daily intake (TDI), showing a low percentage (0.18%) of the TDI reported. This is the first study to examine eight bisphenol analogues and two phenols simultaneously in FCMs using the LC-MS/MS.

Perfluorinated compounds in food simulants after migration from fluorocarbon resin-coated frying pans, baking utensils, and non-stick baking papers on the Korean market

ABSTRACT Perfluorinated compounds (PFCs) are used in manufacturing food contact materials, including non-stick cookware coatings and oil- and moisture-resistant paper coatings. The chemical stability of PFCs poses an issue for human safety, as they do not degrade well naturally and hence may accumulate in the body. In terms of food safety, since dietary intake is thought to be a major source of exposure to PFCs, it is necessary to assess the migration of PFCs from food packaging articles to food under typical cooking and storage conditions. An analytical method was developed for assessing the migration of 16 PFCs from food contact materials to food simulants using liquid chromatography–tandem mass spectrometry. The applicability of the method for regular inspection was assessed by monitoring 312 samples. Based on the results of the exposure assessment, all food contact materials deemed to be safe for use, which evaluated migrated concentrations and dietary food intake.

Fast and simple determination and exposure assessment of bisphenol A, phenol, p-tert-butylphenol, and diphenylcarbonate transferred from polycarbonate food-contact materials to food simulants

Polycarbonate (PC) plastics find extensive use in baby bottles, food storage containers, and various kitchen items. Possibly hazardous chemicals, bisphenol A (BPA), phenol, p-tert-butylphenol (TBP), and diphenylcarbonate (DPC), are source materials or by-products from PC production. Therefore, a fast and simple analytical method was developed to determine and assess the exposure of BPA, phenol, TBP, and DPC transferred from PC food-contact materials to four different food simulants (water, 4% acetic acid, 50% ethanol, and n-heptane) at different temperatures. The method was validated in terms of limit of detection (LOD) and quantification (LOQ), recovery, and precision for the detection of BPA, phenol, and TBP using HPLC-FLD and of DPC using HPLC-UV. BPA, phenol, TBP, and DPC concentrations transferred from 200u202fPC samples to food simulants were determined. The highest migration levels of BPA (54.3u202fμgu202fL-1) and phenol (43.8u202fμgu202fL-1) were found in 50% ethanol at 70u202f°C. TBP did not migrate to any simulant. DPC did not show any migration from PC samples into water and only migrated from a cup to 4% acetic acid at 70u202f°C and 100u202f°C, whereas migration occurred from several cups, ladles, spoons, and tongs to 50% ethanol and to n-heptane at 25u202f°C. Food simulants and temperature were the crucial factors for the migration of BPA and phenol from PC samples. Estimated daily intakes (EDIs), based on food consumption and food-type distribution factors, for BPA, phenol, and DPC were calculated to be 0.007, 0.001, and 2.5u202f×u202f10-4u202fμgu202fkg-1 bw day-1, respectively.

Analytical Survey on the Package Source, Components, and Various Characteristics of Processed Foods in Korea

This study was conducted to investigate the packaging characteristics including pack sources and pack components of processed foods in Korea. For the survey, 704 food package samples were selected based on the consumption of top 10 brackets in each food item. They were consisted of 1,245 packaging components. Seven specific items were firstly investigated including product name, capacity of the food, package component, package source, food contact area, food contact ratio, and package thickness. The processed foods in Korea can be classified into 16 pack sources and 21 pack components, respectively. By using this information, the data were analyzed specifically. The collected data were analyzed in 8 major categories: frequency of use by pack components and pack sources, pack components by the products, pack sources by the products and pack components, pack thickness/food contact ratio by the products, food contact ratio by pack components and pack sources. Consequently, this survey will provide various information of the packaging characteristics of processed foods in Korea.

INFLUENCE OF MONTMORILLONITE NANOCLAY CONTENT ON THE OPTICAL, THERMAL, MECHANICAL, AND BARRIER PROPERTIES OF LOW-DENSITY POLYETHYLENE

Although low density polyethylene (LDPE) has long been widely used in packaging applications, some limitations in its use still exist and are due to its relatively poor gas barrier properties and low mechanical strength which can restrict its extensive use for more advanced applications, such as electronic and pharmaceutical packaging. The purpose of this study was to investigate the possibility of using montmorillonite (MMT) nanoclay as a means to enhance the thermal, mechanical, and barrier properties of LDPE prepared via melt extrusion. The level of exfoliated dispersion of the MMT nanoclay in the prepared LDPE-MMT composite was confirmed using transmission electron microscopy (TEM). The relationship between the resulting morphology and the thermal, mechanical, and barrier properties as a function of the MMT content was evaluated. The results showed that incorporating >3 wt.% of MMT nanoclay produced significant changes in the morphology of the LDPE-MMT nanoclay composite in that the segregated matrix adopted an oriented arrangement of exfoliated clay platelets. Thermogravimetric analysis (TGA) showed that the thermal stability of LDPE improved significantly as a result of MMT nanoclay incorporation. Furthermore, differential scanning calorimetry (DSC) analysis indicated that increasing clay content above 3 wt.% effectively reduces the crystallinity of LDPE-MMT composites through the suppression effect. The tensile strength of LDPE increased gradually with an increased content of MMT nanoclay and the maximum value of 16.89 N/mm2 was obtained at 10 wt.% MMT content. This value represents a 40.87% increase relative to the tensile strength of the pristine LDPE. Barrier properties of LDPE and LDPE-MMT nanoclay composites were assessed by examining the permeability with respect to oxygen and water vapor. As the content of MMT nanoclay was increased to 10 wt.%, the permeability of the nanocomposite films to oxygen and water vapor notably decreased to 42.8% and 26.2%, respectively.