Isolation and identification of microplastics in infant formulas - A potential health risk for children

Microplastics (MPs) are plastic particles between 0.1 and 5,000 µm in size that can contaminate food. Unfortunately, to date, little attention has been paid to analyzing the presence of such particles in baby foods. The present study aimed to determine the degree of contamination of infant formula with MPs. A total of thirty products were subjected to analysis. The research methodology used included the isolation of plastic particles, identification and characterization of MPs using advanced microscopic and spectroscopic techniques. Microplastics were detected in all tested samples. The most frequently identified polymers were polyamide, polyethylene, polypropylene, and poly(ethylene terephthalate). The particles exhibited diverse forms, including fibers, fragments, and films, displaying a range of colors such as colorless, black, and brown particles. Furthermore, the daily intake of MPs by children fed exclusively infant formula was estimated to be approximately 49 ± 32 MPs. This poses a potential health risk for the youngest.

Approaches of lipid oxidation mechanisms in oil matrices using association colloids and analysis methods for the lipid oxidation

Lipid oxidation is one of the key chemical reactions in foods containing fats and oils during production and storage. For several decades, many researchers have tried to understand the mechanisms of lipid oxidation and ways to control the rates of lipid oxidation. Theories of autoxidation or free radical chain reaction have been developed to successfully explain the phenomenon observed in oxidized lipids. Many studies have been conducted to explain the other factors that can affect the lipid oxidation such as food matrix, oxidation time and temperature, transition metal ions, pigments with sensitizing abilities, and surface-active compounds such as phospholipids, free fatty acids, monoacylglycerols, and diacylglycerols. Several strategies were developed to evaluate the degree of oxidation and oxidative stability. This review provides crucial information on the mechanism of lipid oxidation affected amphiphilic compounds and association colloids. This review article will extensively discuss about the methods for determining the oxidative stability.

Feasibility of soil and sludge standards for freshwater sediment pollutant determination and quality judgment

The environmental standards of soil and sludge have been typically referenced for freshwater sediment determination and quality assessment, especially in some areas without sediment standards. The feasibility of determination method and quality standard of soils and sludge for freshwater sediment was investigated in this study. Fractions of heavy metals, nitrogen, phosphorus, and reduced inorganic sulfur (RIS) in different type of samples were determined, including freshwater sediments, dryland and paddy soils, and sludge with air-drying (AD) and freeze-drying (FD) treatment, respectively. Results showed fraction distributions of heavy metals, nitrogen, phosphorus, and RIS in sediments markedly differed from those of soils and sludge. Fraction redistributions of heavy metals, nitrogen, phosphorus, and RIS in sediments were observed with AD compared to those treated by FD. The proportions of heavy metals, nitrogen, and phosphorus associated with organic matter (or sulfide) in FD sediments decreased by 4.8-74.2%, 9.5-37.5%, and 16.1-76.3%, respectively, compared to those in AD sediments, while those associated with Fe/Mn oxides increased by 6.3-39.1%, 50.9-226.9%, and 6.1-31.0%, respectively. The fraction proportions of RIS in sediments with AD also sharply decreased. Determination of standard methods for sludge and soil caused the distortion of pollutant fraction analysis in sediment. Similarly, the quality standard of sludge and soil was inappropriate for sediment quality assessment due to the differences in pollutant fraction pattern between sediment and soils/sludge. Totally, soil and sludge standards are inapplicable for freshwater sediment pollutant determination and quality judgment. This study would greatly advance the establishment of freshwater sediment determination methods and quality standards.

Estimation of contamination level in microplastic-exposed crayfish by laser confocal micro-Raman imaging

Crayfish is one of the most important freshwater aquaculture species in China. The potential risks of crayfish consumption caused by environmental microplastic pollution have attracted much attention. In this study, a total of 72 crayfish samples were exposed to the microplastic concentrations of 1 mg/L, 3 mg/L, and 9 mg/L for 7, 14, and 28 days, and microplastic contamination levels in crayfish were then explored by laser confocal micro-Raman (LCM-Raman) imaging and scanning electron microscope (SEM). LCM-Raman imaging showed better performance in microplastics identification. Besides, the average percentage of the contaminated area in visualized LCM-Raman images was used to quantitatively assess contamination levels. Following 28 days of exposure to 9 mg/L microplastics, microplastic accumulation reached about 13,000 particles per crayfish. The results confirmed that LCM-Raman imaging combined with image processing technology could be used to construct a high-performance analytical strategy for the assessment of microplastic contamination in crayfish.

Presence of microplastics in commercial canned tuna

The present study aims to determine the presence of synthetic polymeric microparticles (MPs) in samples of canned tuna. An analysis procedure of these microparticles was developed and tested. Four brands of tuna marketed in Ecuador canned both in water and oil were analysed. A significant presence of MPs was found: 692 ± 120 MPs/100 g of tuna in water and 442 ± 84 MPs/100 g of tuna in oil. Random samples of the liquid covering the tuna fish in the cans showed 6 MPs/mL in the case of water and 5 MPs/mL in the case of oil-containing samples. A total of 90% of the reported particles presented a size range of 1-50 µm. The number of MPs present in canned tuna suggests that the ingredients and inputs of the canning process greatly contribute to micro polymers. The identification of the microparticles using fluorescence and micro-FTIR spectrometry revealed that PET, polystyrene and nylon were the most frequent MPs present in the samples analysed.

Environmental characteristics and formations of polybrominated dibenzo-p-dioxins and dibenzofurans

Polybrominated dibenzo-p-dioxins and furans (PBDD/Fs) are emerging persistent organic pollutants (POPs) that have similar or higher toxicities than the notorious dioxins. Toxicities, formation mechanisms, and environmental fates of PBDD/Fs are lacking because accurate quantification, especially of higher brominated congeners, is challenging. PBDD/F analysis is difficult because of photolysis and thermal degradation and interference from polybrominated diphenyl ethers. Here, literatures on PBDD/F analysis and environmental occurrences are reviewed to improve our understanding of PBDD/F environmental pollution and human exposure levels. Although PBDD/Fs behave similarly to dioxins, different congener profiles between PBDD/Fs and dioxins in the environment indicates their different sources and formation mechanisms. Herein, potential sources and formation mechanisms of PBDD/Fs were critically discussed, and current knowledge gaps and future directions for PBDD/F research are highlighted. An understanding of PBDD/F formation pathways will allow for development of synergistic control strategies for PBDD/Fs, dioxins, and other dioxin-like POPs.

Analysis Method for Laryngeal High-Speed Videoendoscopy: Development of the Criteria for the Measurement Input

Despite its clear advantages, laryngeal high-speed videoendoscopy (LHSV) has not yet been accepted as a routine imaging tool for the evaluation of vocal fold vibration due to the unavailability of methods to effectively analyze the huge number of images from the LHSV recording. Recently, a promising LHSV-based analysis method has been introduced. The ability of this analysis method in studying the vocal fold vibratory behaviors had been substantially demonstrated. However, some practical aspects of its clinical applications still require further attention. Most fundamental is that the criteria for the measurement input ie, a segment of interest (SOI), which has not been fully defined. Particularly, the length of the SOI and the location along the sample, where it needs to be selected require further confirmation. Meanwhile, the analysis using any options of a well-delineated glottal area demands verification. Without clear criteria for the SOI, it is difficult to demonstrate the relevance of this analysis method in clinical voice assessment. Therefore, the aim of the present study is to establish the criteria for the SOI, which involved the investigations on the length of the SOI and the location along the sample, where it needs to be selected, as well as the use of any options of a well-delineated glottal area for analysis. The participants in the present study consisted of 36 young normophonic females. The methods involved LHSV recording of the images of the vibrating vocal folds. The captured images were then analyzed using the method. The LHSV-based measures from the analyses were compared according to the specified procedures of each investigation. Results indicated that 2000 frames should be used as the SOI length. The SOI could be selected at any location along the sample as long as well-delineated glottal areas were observed. With the current findings, a more conclusive measurement protocol is available to ensure reliable LHSV-based measures. The findings further support this analysis method for clinical application, which in turn promote LHSV as a reliable laryngeal imaging tool in clinical setting.

Developing a high-performance liquid chromatography fast and accurate method for quantification of silibinin

Objective

Silibinin is an antioxidant agent and is shown to have anticancer effects in different cancers including lung, breast, colorectal, liver, prostate, and kidney. There are challenges in the clinical use of silibinin. The main limitation is low solubility, poor oral absorption, and extensive hepatic metabolism. We aim to develop a High-Performance Liquid Chromatography (HPLC) sensitive method for quantification of silibinin in aqueous samples to quantify its concentration in new formulations. A reverse-phase high-performance liquid chromatography (RP-HPLC) composed of C18 column as stationary phase and the mixture of methanol (90%) and water (10%) as mobile phase. The developed method was validated based on the established guidelines.

Results

The retention time for silibinin was seen in 2.97 min after injection. The calibration curve was drawn and the established method demonstrated a linear ranged from 10 to 100 µg/ml, with a correlation coefficient of 0.996. The sensitivity of the developed method was 10 µg/ml. The accuracy calculated in the range of 88–105.9% and the precision (as relative standard deviation) was between 2.7 and 10.9%. These results demonstrate that the developed method can be a fast and accurate method for quantification of silibinin in aqueous samples.

Pharmacokinetic study of salvianolic acid D after oral and intravenous administration in rats

A sensitive, specific and rapid LC-MS method was developed and validated for the determination of salvianolic acid D (SalD) in rat plasma. This method used a single quadrupole mass spectrometer with an electrospray ionization (ESI) source. A single ion monitoring scanning (SIM) mode was employed. It showed good linearity over the concentration range from 3.3 to 666.7 ng/mL for the determination of SalD. The R.S.D.% of intra-day and inter-day precision values were no more than 7.69%, and the accuracy was within 91%−104% at all quality control levels. This LC-MS method was applied to the pharmacokinetic study of SalD in rats. A two-compartmental model analysis was employed. The plasma concentrations at 2 min (C_2min) were 5756.06±719.61, 11,073.01±1783.46 and 21,077.58±5581.97 μg/L for 0.25, 0.5 and 1 mg/kg intravenous injection, respectively. The peak plasma concentration (C_max) was 333.08±61.21 μg/L for 4 mg/kg oral administration. The area under curve (AUC_0−t) was 14,384.379±8443.184, 22,813.369±11,860.823, 46,406.122±27,592.645 and 8201.740±4711.961 μg/L·h for intravenous injection (0.25, 0.5 and 1 mg/kg) and oral administration (4 mg/kg), respectively. The bioavailability of SalD was calculated to be 4.159%±0.517%.

Measurement uncertainties in quantifying aeolian mass flux: evidence from wind tunnel and field site data

Aeolian sediment traps are widely used to estimate the total volume of wind-driven sediment transport, but also to study the vertical mass distribution of a saltating sand cloud. The reliability of sediment flux estimations from such measurements are dependent upon the specific configuration of the measurement compartments and the analysis approach used. In this study, we analyse the uncertainty of these measurements by investigating the vertical cumulative distribution and relative sediment flux derived from both wind tunnel and field studies. Vertical flux data was examined using existing data in combination with a newly acquired dataset; comprising meteorological data and sediment fluxes from six different events, using three customized catchers at Ameland beaches in northern Netherlands. Fast-temporal data collected in a wind tunnel shows that the median transport height has a scattered pattern between impact and fluid threshold, that increases linearly with shear velocities above the fluid threshold. For finer sediment, a larger proportion was transported closer to the surface compared to coarser sediment fractions. It was also shown that errors originating from the distribution of sampling compartments, specifically the location of the lowest sediment trap relative to the surface, can be identified using the relative sediment flux. In the field, surface conditions such as surface moisture, surface crusts or frozen surfaces have a more pronounced but localized effect than shear velocity. Uncertainty in aeolian mass flux estimates can be reduced by placing multiple compartments in closer proximity to the surface.