Quantification of bisphenols in Korean urine using online solid-phase extraction-high-performance liquid chromatography-tandem mass spectrometry.

Bisphenol A (BPA), an endocrine-disrupting chemical, has been used as a basic raw material for the production of polycarbonate plastics. As concern over the toxic effects of BPA grows, it is gradually being replaced in many consumer products with compounds such as bisphenol F (BPF) and bisphenol S (BPS). In this study, online solid-phase extraction-high-performance liquid chromatography-tandem mass spectrometry was used to analyze the urinary concentrations of BPA, BPF, and BPS in 2487 Korean urine samples collected between 2017 and 2018. The detection rates and geometric mean (GM) concentrations were as follows: BPA (82.1 %; 0.65 µg/L), BPF (11.1 %; not calculated), and BPS (63.6 %; 0.20 µg/L), respectively. The mean daily intake based on urinary BPA concentrations was 0.013 µg/kg bw/day (95th percentile, 0.089 µg/kg bw/day), which is lower than the tolerable daily intake. This is the first study observing urinary BPA, BPF, and BPS concentrations based on a nationally representative Korean population and could contribute to the evaluation of bisphenol analogue exposure levels in risk assessments.

Migration of lead and arsenic from food contact paper into a food simulant and assessment of their consumer exposure safety.

Paper is one of the most commonly used food packaging materials. During the production of packaging paper, it is possible for trace amounts of heavy metals to be incorporated as contaminants. These could migrate into food when packaging paper (food contact paper) is used for cooking, storing and eating. The aim of this study was to determine the migration of lead (Pb) and arsenic (As) from food contact paper into a food simulant and then to assess human safety through the estimated daily intake (EDI) with consumption factor. Migration tests were conducted for 310 samples using 4% acetic acid as a food simulant at 25°C for 10 min and at 95°C for 30 min. Concentrations of Pb and As in a food simulant were quantified by inductively coupled plasma mass spectrometry. LODs for Pb and As were 0.002 and 0.005 µg L-1, respectively. The migration of Pb from food contact paper ranged from not detected (ND) to 17.5 µg L-1 at 25°C for 10 min and from 0.10 to 25.6 µg L-1 at 95°C for 30 min while As ranged from ND to 0.44 µg L-1 at 25°C for 10 min and from ND to 0.87 µg L-1 at 95°C for 30 min. The migration of Pb and As determined in this study confirm that the human exposure was within safe levels based on the EDI of food contact paper compared with the provisional tolerable weekly intake for Pb of 25 µg kg-1 bw and for As of 15 µg kg-1 bw.

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

Ensuring 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 (0.46-3.87 µg/kg), limits of quantification (1.38-11.73 µg/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 3.67 µg/kg. NDMA and NMOR concentrations ranged from ND to 1.72 µg/kg after migration from 45 rubber kitchen tools. N-nitrosatable substances ranged from ND to 42.16 µg/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.

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

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.

Effects of Magnetic and Electric Field Uniformity on Coded Aperture Imaging Quality in a Cycloidal Mass Analyzer.

Cycloidal mass analyzers are unique sector mass analyzers as they exhibit perfect double focusing, making them ideal for incorporating spatial aperture coding, which can increase the throughput of a mass analyzer without affecting the resolving power. However, the focusing properties of the cycloidal mass analyzer depend on the uniformity of the electric and magnetic fields. In this paper, finite element simulation and charged particle tracing were used to investigate the effect of field uniformity on imaging performance of a cycloidal mass analyzer. For the magnetic field, we evaluate a new permanent magnet geometry by comparing it to a traditional geometry. Results indicate that creating an aperture image in a cycloidal mass spectrometer with the same FWHM as the slit requires less than 1% variation in magnetic field strength along the ion trajectories. The new magnet design, called the opposed dipole magnet, has less than 1% field variation over an area approximately 62 × 65 mm; nearly twice the area available in a traditional design of similar size and weight. This allows ion imaging across larger detector arrays without loss of resolving power. In addition, we compare the aperture imaging quality of a traditionally used cycloidal mass spectrometer electric design with a new optimized design with improved field uniformity. Graphical abstract ᅟ.