Development of a wet digestion method for paints for the determination of metals and metalloids using inductively coupled plasma optical emission spectrometry

Chemical contaminants from food contact materials and articles made from or containing wood and bamboo - a review

Due to recently introduced 'so-called' bio- and plant-based friendly food contact materials and articles (FCM/FCA), some neglected safety issues need to be raised. In this review, potential chemical contaminants from FCM/FCA made from or containing wood and bamboo are presented. Sources, migration, and analytical issues in determining contaminants including intentionally and non-intentionally added substances (IAS and NIAS, respectively) are reviewed. Most of the contaminants are components from melamine-formaldehyde-resin (MFR), paints and coatings, preservatives, and bleaching agents. Tableware made of MFR containing bamboo fibres as a filler are not always suitable for use as tableware since harmful amounts of melamine and formaldehyde can migrate from the tableware into food and even accelerate the degradation of certain polymers with which they are mixed. In addition, in the EU bamboo in plastic FCM is not authorized under Regulation (EU) 10/2011. Paints and coatings used to provide surface coverage for bamboo and wooden articles also pose a risk of migration of heavy metals. Limits on preservatives in wood FCM are covered by legislation in many countries, nevertheless their contamination should not be ignored. Some wood species are considered 'toxic' or contain 'toxic' constituents that should not be used in contact with food, which are worth considering for legislation. IAS analyses in bamboo and wooden FCM is generally not a problem, but has proven to be more challenging for NIAS. Due to a complex mixture of substances contained in plant-based materials, there is a need to improve databases for non-target screening of such chemicals.

Heavy Metals in Acrylic Color Paints Intended for the School Children Use: A Potential Threat to the Children of Early Age

Heavy metals are the harmful elements, regarded as carcinogens. Nevertheless, owing to their physical and chemical properties, they are still used in the production of several commercial products. Utilization of such products increases the chance for the exposure of heavy metals, some of them are categorized as probable human carcinogens (Group 1) by the International Agency for Research on Cancer. Exposure of heavy metals to school children at early age can result severe life time health issues and high chance of emerging cancer. Thus, we have performed study relating to the presence of heavy metals in acrylic color paints commonly used by the school children. Acrylic paints of different colors were assayed for seven potential heavy metals manganese (Mn), cobalt (Co), nickel (Ni), zinc (Zn), arsenic (As), cadmium (Cd) and lead (Pb) using microwave digestion and iCAPQ inductively coupled plasma mass spectrometry (ICP-MS) system. The optimized method including paints digestion reagents nitric acid (HNO3, 65%, 5 mL) and hydrofluoric acid (HF, 40%, 2 mL) have offered excellent method performance with recovery values ranged between 99.33% and 105.67%. The elements were identified in all of the analyzed samples with concentrations ranged from 0.05 to 372.59 µg/g. Cd constitutes the lower percentage (0.05%), whereas Zn constitutes high ratio contribution which was tremendously high (68.33%). Besides, the paints contamination was also color specific, with considerably total heavy metal concentrations found in brunt umber (526.57 µg/g) while scarlet color (12.62 µg/g) contained lower amounts. The outcomes of our investigation highlight the necessity for guidelines addressing the heavy metals in acrylic color paints intended for the school children usage.

Characterisation of Engineered Nanomaterials in Nano-Enabled Products Exhibiting Priority Environmental Exposure

Analytical limitations have constrained the determination of nanopollution character from real-world sources such as nano-enabled products (NEPs), thus hindering the development of environmental safety guidelines for engineered nanomaterials (ENMs). This study examined the properties of ENMs in 18 commercial products: sunscreens, personal care products, clothing, and paints—products exhibiting medium to a high potential for environmental nanopollution. It was found that 17 of the products contained ENMs; 9, 3, 3, and 2 were incorporated with nTiO₂, nAg, binaries of nZnO + nTiO₂, and nTiO₂ + nAg, respectively. Commonly, the nTiO₂ were elongated or angular, whereas nAg and nZnO were near-spherical and angular in morphology, respectively. The size ranges (width × length) were 7–48 × 14–200, 34–35 × 37–38, and 18–28 nm for nTiO₂, nZnO, and nAg respectively. All ENMs were negatively charged. The total concentration of Ti, Zn, and Ag in the NEPs were 2.3 × 10⁻⁴–4.3%, 3.4–4.3%, and 1.0 × 10⁻⁴–11.3 × 10⁻³%, respectively. The study determined some key ENM characteristics required for environmental risk assessment; however, challenges persist regarding the accurate determination of the concentration in NEPs. Overall, the study confirmed NEPs as actual sources of nanopollution; hence, scenario-specific efforts are recommended to quantify their loads into water resources.

Determination of total and bioavailable As and Sb in children's paints using the MSFIA system coupled to HG-AFS

In this study, the use of hydride generation atomic fluorescence spectrometry (HG-AFS) coupled with the multi-syringe flow injection analysis (MSFIA) has been proposed in the application of the Doehlert design to optimise the determination of As and Sb in gouache and tempera children's paints. The determination of the total and bioavailable As and Sb in paint samples from various brands and colours was also investigated. The limits of quantification (LOQ) obtained for the determination of As and Sb were 14.0 and 8.6 ng g-1, respectively. The accuracy and precision of the method were evaluated through recovery tests (by the analyte addition method) at three levels for both elements, and by the analysis of certified reference materials of clay (CRM 052, Loamy Clay 1) and river water (SLRS-4). Twenty paint samples, manufactured in China, Italy, Spain and Brazil, were analysed. The concentrations of As varied between below LOQ (<14 ng g-1) and 136.0 ± 1.1 ng g-1 (average value of 101.0 ng g-1, n = 10), and Sb between below LOQ (<8.6 ng g-1) and 74.0 ± 5.4 ng g-1 (average value of 21.7 ng g-1, n = 17). The children's paint samples presented As and Sb concentrations that were below the maximum values established by the National Institute of Metrology, Quality and Technology (INMETRO), as well as by the European legislation Directive 2009/48/EC. Based on the obtained results for the total As and Sb concentrations, eight samples were selected to evaluate the migration or bioavailability of As and Sb after solubilisation in HCl solution. The obtained results showed that for the eight analysed samples, the concentration of both elements after solubilisation in HCl solution were below the LOQ (<16.2 ng g-1 for As and <7.1 ng g-1 for Sb). These values correspond to the limits of analytical concentrations of As and Sb established by INMETRO and the Brazilian Association of Technical Standards (ABNT). The determined concentrations of As and Sb guarantee the safety (with regards to these elements) for children when using the analysed paint samples since they do not cause any health risk. The analytical method for the determination of the total and bioavailable As and Sb in children's paints was efficient, accurate and precise.

Interpol review of glass and paint evidence 2016-2019

This review paper covers the forensic-relevant literature in paint and glass evidence from 2016 to 2019 as a part of the 19th Interpol International Forensic Science Managers Symposium. The review papers are also available at the Interpol website at: https://www.interpol.int/content/download/14458/file/Interpol%20Review%20Papers%202019.pdf.

High-Precision (MC-ICPMS) Isotope Ratio Analysis Reveals Contrasting Sources of Elevated Blood Lead Levels of an Adult with Retained Bullet Fragments, and of His Child, in Milwaukee, Wisconsin

Exposure to the neurotoxic element lead (Pb) continues to be a major human health concern, particularly for children in US urban settings, and the need for robust tools for assessment of exposure sources has never been greater. The latest generation of multicollector inductively coupled plasma mass spectrometry (MC-ICPMS) instrumentation offers the capability of using Pb isotopic signatures as a tool for environmental source tracking in public health. We present a case where MC-ICPMS was applied to isotopically resolve Pb sources in human clinical samples. An adult male and his child residing in Milwaukee, Wisconsin, presented to care in August 2015 with elevated blood lead levels (BLLs) (>200 μg/dL for the adult and 10 μg/dL for the child). The adult subject is a gunshot victim who had multiple bullet fragments embedded in soft tissue of his thigh for approximately 10 years. This study compared the high-precision isotopic fingerprints (<1 ‰ 2σ external precision) of Pb in the adult's and child's whole blood (WB) to the following possible Pb sources: a surgically extracted bullet fragment, household paint samples and tap water, and a Pb water-distribution pipe removed from servicing a house in the same neighborhood. Pb in the bullet and adult WB were nearly isotopically indistinguishable (matching within 0.05-0.56 ‰), indicating that bullet fragments embedded in soft tissue could be the cause of both acute and chronic elevated blood Pb levels. Among other sources investigated, no single source dominated the child's exposure profile as reflected in the elevated BLL.

Total tin and organotin speciation in historic layers of antifouling paint on leisure boat hulls

Despite their ban on small vessels in 1989 in the EU, organotin compounds (OTCs) are still being released into the environment due to their presence in historic paint layers on leisure boats. 23 paint samples scraped from recreational boats from three countries around the Baltic Sea were analyzed for total tin (Sn) and OTCs. Two antifouling paint products were also subjected to the same analyses. A new method for the detection of Sn in paint flake samples was developed and found to yield more accurate results compared to four different acid digestion methods. A new method was also developed for the extraction of OTCs from ground paint flakes. This endeavor revealed that existing methods for organotin analysis of sediment may not have full recoveries of OTCs if paint flakes are present in the sample. The hull paint samples had Sn concentrations ranging from 25 to 18,000 mg/kg paint and results showed that tributyltin (TBT) was detected in all samples with concentrations as high as 4.7 g (as Sn)/kg paint. TBT was however not always the major OTC. Triphenyltin (TPhT) was abundant in many samples, especially in those originating from Finland. Several other compounds such as monobutyltin (MBT), dibutyltin (DBT), tetrabutyltin (TeBT), monophenyltin (MPhT) and diphenyltin (DPhT) were also detected. These could be the result of degradation occurring on the hull or of impurities in the paint products as they were also identified in the two analyzed paint products. A linear correlation (r² = 0.934) was found between the total tin content and the sum of all detected OTCs. The detection of tin can therefore be used to indicate the presence of OTCs on leisure boats.