Blank Samples Research Articles

Controllable Technology for Thermal Expansion Coefficient of Commercial Materials for Solid Oxide Electrolytic Cells.

Solid oxide electrolysis cell (SOEC) industrialization has been developing for many years. Commercial materials such as 8 mol% Y2O3-stabilized zirconia (YSZ), Gd0.1Ce0.9O1.95 (GDC), La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF), La0.6Sr0.4CoO3-δ (LSC), etc., have been used for many years, but the problem of mismatched thermal expansion coefficients of various materials between cells has not been fundamentally solved, which affects the lifetime of SOECs and restricts their industry development. Currently, various solutions have been reported, such as element doping, manufacturing defects, and introducing negative thermal expansion coefficient materials. To promote the development of the SOEC industry, a direct treatment method for commercial materials-quenching and doping-is reported to achieve the controllable preparation of the thermal expansion coefficient of commercial materials. The quenching process only involves the micro-treatment of raw materials and does not have any negative impact on preparation processes such as powder slurry and sintering. It is a simple, low-cost, and universal research strategy to achieve the controllable preparation of the thermal expansion coefficient of the commercial material La0.6Sr0.4Co0.2Fe0.8O3-δ (LSCF) through a quenching process by doping elements and increasing oxygen vacancies in the material. Commercial LSCF materials are heated to 800 °C in a muffle furnace, quickly removed, and cooled and quenched in 3.4 mol/L of prepared Y(NO3)3. The thermal expansion coefficient of the treated material can be reduced to 13.6 × 10-6 K-1, and the blank sample is 14.1 × 10-6 K-1. In the future, it may be possible to use the quenching process to select appropriate doping elements in order to achieve similar thermal expansion coefficients in SOECs.

Ultra-performance liquid chromatography-tandem mass spectrometry for quantification of pyrethroid pesticide residues in freshwater fish and shrimp

A sophisticated Ultra-Performance Liquid Chromatography-Tandem Mass Spectrometry (UPLC-MS/MS) approach was devised for the concurrent quantification of pyrethroid pesticide residues in freshwater fish and shrimp. This analytical method involved ultrasonic extraction using acetonitrile, succeeded by sample purification employing Primary Secondary Amine (PSA) and Zirconium Dioxide Silica (Z-Sep+) following low-temperature centrifugation. Chromatographic separation was achieved with an ACQUITY UPLC BEH C18 column utilizing a mobile phase of a 2 mmol/L ammonium formate aqueous solution and methanol, with detection conducted through ESI + ionization in Multiple Reaction Monitoring (MRM) mode. The assay demonstrated exceptional linearity for seven pyrethroids across a concentration range of 0.5–10 μg/L, evidenced by correlation coefficients surpassing 0.999. Detection limits were established between 0.08 and 0.52 μg/kg, and the lower limits of quantification ranged from 0.28 to 1.72 μg/kg. Furthermore, recovery rates for blank samples were outstanding, ranging from 91.40% to 108.83% at concentrations of 1.0, 4.0, and 20.0 μg/kg, with Relative Standard Deviations (RSDs) between 0.94% and 8.13%. This methodology proved to be rapid, convenient, sensitive, and robust, offering stable recovery rates. Notably, it facilitated the detection of seven pyrethroid pesticide residues in freshwater fish and shrimp within an expedited timeframe of 15 min. This pioneering technique constitutes a significant advancement in the development of new methods for ensuring food safety.

Properties and corrosion mechanism of Al2O3–SiC–C refractories for hot metal ladle with high FeOx: Effect of in-situ MgAl2O4

Addressing increased damage to hot metal ladle refractory linings from FeOx of scrap steel, Al2O3–SiC–C refractories were prepared at 1400 °C with corundum, SiC, graphite as raw materials, and fused magnesia as additives. The impacts of additives on phase changes, microstructure, and properties were researched. The findings indicate that the oxide layer of Al2O3–SiC–C refractories with in-situ generated MgAl2O4 is denser than that of the blank sample after the oxidation test. This denser layer effectively inhibits the diffusion of O2, leading to a significant enhancement in oxidation resistance. After the corrosion test, it was observed that a part of Al2O3 was wrapped by Mg(Al, Fe)2O4 at the interface between the sample with generated in-situ MgAl2O4 and the slag. This structure can ensure the integrity of the material structure and fix some Fe2+ to weaken its corrosion to the refractory components, and its corrosion resistance is higher than that of the blank sample.

NPS–EQA PART I: Four years’ experience in external quality assessment program in Italy for classical and new psychoactive substances analysis in oral fluid

In 2019, Italian National Institute of Health established an external quality assessment program (EQA) to evaluate the performance of oral fluid testing for classical and new psychoactive substances by laboratories participating in the National Early Warning System collaborative centres. This report presents the results of four rounds between 2019 and 2023. Eleven oral fluid specimens, including 3 blank samples, were prepared by adding different classes of and new psychoactive drugs at known concentrations to pre-screened drug-free oral fluid. False-negative and false-positive results were calculated for the qualitative data evaluation. The quantitative evaluation measured the imprecision and accuracy of the results, in terms of coefficient of variation (CV%) and percent error (ERR%), respectively, with respect to a mean value obtained by reference laboratories. Z-score values were then calculated. Over the years, there has been a significant improvement in false-negative results (from 42.7% in the first year to 19.4% in the last year), but not in false-positive results (from 33.3% in the first year to 22.2% in the last one). In addition to the classic drugs of abuse (e.g. cocaine, amphetamine, methadone), the substances found in false positive samples belonged to the class of synthetic cannabinoids (e.g 5-fluoro CUMYL-PINACA and 5-fluoro-EDMB-PICA), synthetic opioids (e.g butyrylfentanyl) and tryptamines (e.g. 5-methoxy-N-methyl-N-isopropyltryptamine). The four rounds yielded a mean ERR% of approximately 22.1% and a mean CV% of around 41.5%. The participating laboratories demonstrated variable performances in relation to the class of analysed psychoactive substances, as evidenced by the calculated Z-scores. Between 25% and 60% of the reported results in all rounds should be considered satisfactory. EQA is a crucial element of laboratory quality management systems. It promotes continuous improvement and maintains high standards in the field of forensic and clinical drug testing.

Microstructural Characterisation of Adsorbent Ash with Potentially Toxic Elements in a Mortar

Abstract Potentially toxic elements (PTEs) in ecosystems and construction materials pose a significant environmental concern. Various qualitative and quantitative techniques are employed to analyse PTEs in a sample. This study explores an innovative approach that incorporates PTE (Cd, Zn, Cu, Pb) adsorbent ash, specifically adsorbed paper ash (APA) and adsorbed mulch ash (AMA), into mortar composites. This approach offers several advantages, including reduced reliance on waste landfills, energy recovery during the ashing process, and immobilisation of PTEs within a cement matrix. This study evaluated the elemental and microstructural characteristics of mortar composites incorporated with adsorbed ash by using a scanning electron microscope (SEM) equipped with energy-dispersive X-ray spectroscopy (EDS), followed by analysing the elemental maps with ImageJ software version 1.8.0. Parallel experiments were conducted to measure the leaching of mortar composites. The total elemental content of PTEs in the leachate solutions was quantified using an inductively coupled plasma-optical emission spectrometer (ICP-OES). The differences in adsorption capacity and leaching of PTEs observed between paper and mulch can be ascribed to their distinct affinities, which are influenced by the recorded pH levels. The examined elemental mapping revealed a consistent distribution across the APA and AMA mortar matrix structures, with greater intensity than the blank mortar sample. Furthermore, there is a reverse correlation between the order of percentage area coverage of the immobilised elements and the order of leaching, indicating that the PTEs were successfully immobilised. The percentage of PTE area coverage within AMA mortar composites followed the subsequent order: Pb > Cd > Zn > Cu, constituting 32.1 %, 28.6 %, 13.8 %, and 12.4 %, respectively. This order was also observed in the blank mortar composite, with percentages of 12.5 %, 8.6 %, 4.5 %, and 4.2 %, respectively. In the case of the APA mortar composite, the percentage of area coverage followed a different sequence: Cd > Pb > Zn > Cu, representing 27.7 %, 26.6 %, 14.5 %, and 14.1 %, respectively. The results also demonstrated notable improvements in the microstructure of the mortar when AMA and APA are incorporated, which is attributed to the ash additives’ micro-filling capacity. The findings contribute to advancing environmentally sound construction practices, with implications for sustainable waste management and pollution mitigation.

Low blank sampling method for measurement of the nitrogen isotopic composition of atmospheric NOx.

The nitrogen isotopic composition of nitrogen oxide (NOx) is useful for estimating its sources and sinks. Several methods have been developed to convert atmospheric nitric oxide (NO) and/or nitrogen dioxide (NO2) to nitrites and/or nitrates for collection. However, the collection efficiency and blanks are poorly evaluated for many collection methods. Here, we present a method for collecting ambient NOx (NO and NO2 simultaneously) with over 90% efficiency collection of NOx and low blank (approximately 0.5 μM) using a 3 wt% hydrogen peroxide (H2O2) and 0.5 M sodium hydride (NaOH) solution. The 1σ uncertainty of the nitrogen isotopic composition was ± 1.2 ‰. The advantages of this method include its portability, simplicity, and the ability to collect the required amount of sample to analyze the nitrogen isotopic composition of ambient NOx in a short period of time. Using this method, we observed the nitrogen isotopic compositions of NOx at the Tsukuba and Yoyogi sites in Japan. The averaged δ15N(NOx) value and standard deviation (1σ) in the Yoyogi site was (-2.7 ± 1.8) ‰ and in the Tsukuba site was (-1.7 ± 0.9) ‰ during the sampling period. The main NOx source appears to be the vehicle exhaust in the two sites.

Performance Evaluation of a Commercial Real-Time PCR Method for the Detection of Lupin Traces in Food.

In accordance with U.S. FDA Foods Program Regulatory Science Steering Committee guidelines, with this study, we optimized and validated a commercial real-time PCR method for the detection of low amounts of lupin in four classes of food matrices: chocolate cookies, ragù, Olivier salad, and barley and rice flour. DNA extracted from blank (true negative) samples artificially contaminated with lupin (Lupinus albus) flour at 1000 ppm underwent dilutions with the DNA extracted from the true negative samples up to 0.5 ppm. The limit of detection for real-time PCR was 0.5 ppm in the complex matrices (range, Ct 26-34), making this a specific, robust, and rapid method for lupin allergen detection and labeling. Our validation data support the suitability of this commercially available real-time PCR method for this purpose.

Effect of hydroxypropyl methylcellulose (HPMC) hard capsules on in vitro rumen fermentation kinetics of commonly used feeds in ruminant feeding.

Accurate dosing of feed additives is often required to evaluate their effects on rumen fermentation. This can be done using soluble but nonfermentable hydroxypropyl methylcellulose (HPMC) hard capsules. The aim of the study was to evaluate the effect of HPMC hard capsules on the extent and rate of in vitro gas production in eleven feeds. Six high-fibre feeds and five concentrates, were weighed into syringes either directly or into HPMC capsules and incubated anaerobically in 30mL buffered rumen fluid at 39°C. Data obtained from gas production measurements were fitted using the Gompertz model to obtain kinetic parameters for gas production. HPMC hard capsules had no effect on the gas production of the blank sample and concentrate feeds. In contrast, high-fibre feeds weighed in HPMC showed a significant decrease (p < 0.05) in total gas production and gas produced within 24 h of incubation. The use of HPMC hard capsules was found to be inappropriate for determining gas production kinetics because fermentation subsides at a certain point when peak fermentation is reached (at TMFR), resulting in a decrease in both total potential gas production and gas production within 24 h of incubation. This is particularly evident when high-fibre feeds are incubated.

Determination of cyclic volatile methylsiloxanes in sludge samples collected from To Lich River, Hanoi, Vietnam

Cyclic volatile methylsiloxanes (cVMSs) are synthesis chemicals used widely in consumer products such as building materials, households, electrical and medical devices, and personal care products. Due to being used in many applications, cVMSs are released into various micro-environments. Recently, the pollution level of cVMSs in the environment including sewage sludge has been gradually concerned. In this work, four typical cVMSs: hexamethylcyclotrisiloxane (D3), octamethylcyclotetrasiloxane (D4), decamethylcyclopentasiloxane (D5), and dodecamethylhexasiloxane (D6) were measured in 20 sludge samples collected from a sewage river (To Lich River) in Ha Noi metropolitan by using the gas chromatography-tandem mass spectrometry (GC-MS) method. The method detection limits (MDLs) and the method qualification limits (MQLs) of cVMSs in sewage sludge were a range of (1.20-3.00) ng/g-dw (dry weight) and (3.60-9.00) ng/g-dw, respectively. Recoveries of the surrogate compound (tetrakis-(trimethyl siloxane)-silane: M4Q) in blank and real samples were from (89.4 to 112) % (RSD: 9.2 %). The total concentrations of cVMSs in sewage sludge samples from To Lich River ranged from (260 to 13,800) ng/g-dw. Among the studied cVMSs, D5 was found at the highest levels in a range of (150-6,040) ng/g-dw. To our knowledge, this is the first report on the occurrence of cVMSs in sewage sludge samples in Ha Noi as well as Vietnam. The results indicate that the distribution of cVMSs in environments is significantly high and further studies should be conducted. ® 2023 Journal of Science and Technology - NTTU

Study on determination of PAEs in water samples by using solid phase extraction combined with gas chromatography-mass spectrometry

Phthalic acid diesters (PAEs) are industrial chemicals used as plasticizers in a variety of commercial products. Due to wide usage, PAEs have been found in various environments and their human exposure risks have also attracted a lot of concerns. However, little information about the distributions of PAEs in the water samples collected from Vietnam was reported. In this study, the method for the determination of nine typical PAEs in water samples by using the solid phase extraction (SPE) combined with gas chromatography-mass spectrometry (GC-MS) technique was optimized. The method detection limits (MDLs) and method quantitation limits (MQLs) of PAEs in water samples were in ranges of 0.2–0.4 ng/L and (0.6-1.2) ng/L, respectively. The recoveries of surrogate compounds in blank and real samples ranged from (74.8 to 93.9) %, with RSD &lt; 9.2 %. The calibration curve for all standards was linear over a concentration range of (1.0-1,000) ng/mL (with R2 ≥ 0.998). The total concentrations of PAEs measured in bottled water of six brands were ranged from 10.0 ng/L to 6,690 ng/L. Among the studied PAEs, di-(2-ethylhexyl) phthalate (DEHP) was found at the highest frequencies and concentrations. Overall, the distribution of PAEs in plastic bottled water is significantly lower than the permitted regulations (only with DEHP) in drinking water by the Ministry of Health of Vietnam in 2011. ® 2023 Journal of Science and Technology - NTTU

Transforming polypropylene waste into transparent anti-corrosion weather-resistant and anti-bacterial superhydrophobic films

The global pollution crisis arising from the accumulation of plastic in landfills and the environment necessitates addressing plastic waste issues. Notably, polypropylene (PP) waste accounts for 20% of total plastic waste and holds promise for hydrophobic applications in the realm of recycling. Herein, the transparent and non-transparent superhydrophobic films made from waste PP are reported. A hierarchical structure with protrusions is induced through spin-casting and thermally induced phase separation. The films had a water contact angle of 159° and could vary in thickness, strength, roughness, and hydrophobicity depending on end-user requirements. The Bode plot indicated enhanced corrosion resistance in the superhydrophobic films. Antibacterial trials with Escherichia coli and Staphylococcus aureus microbial solutions showed that the superhydrophobic film had a significantly lower rate of colony-forming units compared to both the transparent surface and the control blank sample. Moreover, a life cycle assessment revealed that the film production resulted in a 62% lower embodied energy and 34% lower carbon footprint compared to virgin PP pellets sourced from petroleum. These films exhibit distinctiveness with their dual functionality as coatings and freestanding films. Unlike conventional coatings that require chemical application onto the substrate, these films can be mechanically applied using adhesive tapes on a variety of surfaces. Overall, the effective recycling of waste PP into versatile superhydrophobic films not only reduces environmental impact but also paves the way for a more sustainable and eco-friendly future.

Preparation and performance evaluation of graphene-based waterborne thermal conductive coatings

Thermal management of electronic products and communication equipment is a key bottleneck restricting the integration of products, and high-performance thermal management materials are an effective means to solve this problem. In this study, graphene prepared by liquid phase exfoliation was used as a functional additive material to successfully prepare a graphene high-thermal-conductivity coating material on stainless steel substrates for enhanced cooling performance. The research found that the thermal conductivity of different coating materials with different graphene contents significantly varies, and when the graphene content is 15 %, the thermal conductivity can reach as high as 9.499 W/(m·K), which can rapidly achieve heat dissipation. Considering the actual working conditions of the thermal coating, the comprehensive performance of the coating was tested, and it has excellent corrosion resistance and excellent temperature cycling resistance. Under experimental conditions, after adding the thermal coating to the stainless steel substrate, its cooling effect significantly improved. Compared with uncoated blank samples, the maximum temperature difference during heat transfer under room temperature can reach 11 °C, and the maximum temperature difference under −80 °C can reach 19 °C. This study's coating has potential application prospects in the field of thermal management.

Biphasic Porous Bijel-Like Structures with Hydrogel Domains as Controlled Drug Delivery Systems.

Bijels are a peculiar type of Pickering emulsion that have a bicontinuous morphology and are stabilised by a jammed layer of nanoparticles (NPs). Due to their double nature, their usage has increased in recent years in various fields, such as biological and food applications. In fact, they can release both hydrophilic and hydrophobic compounds simultaneously. An improvement to this structure is the use of a hydrophobic monomer like polycaprolactone as the organic phase, which is able to polymerise during the formation of the structure. Unfortunately, the structures formed in this way always have some drawbacks, such as their thermal stability or degradation when submerged in an aqueous medium. A number of studies have been carried out in which some parameters, such as the NPs or the monomer, were changed and their effect on the final product evaluated. In this work, the effect of modifying the aqueous phase was studied. In particular, the effect of adding alginate, a biopolymer capable of forming a stable hydrogel in the presence of divalent cations, was analysed, as was the difference between soaking or not in CaCl2, the final system. Specific attention was paid to their swelling behaviour (150% vs. 25% of the blank sample), rheological properties (G' 100 kPa vs. 20 kPa of the blank sample) and their release performances. In this framework, complete release of hydrophilic drug vs. 20% in the blank sample was observed together with improved release of the hydrophobic one with 35% in 8 h vs. 5% in the case of the blank sample. This strategy has been proven to influence bijels' properties, opening the doors to many different uses.

Carbon nanotubes in high internal phase emulsion polymer composite for packed-cartridge micro-solid-phase extraction of fluoroquinolones in urine

Aim of this study stands in the evaluation of a carbon nanotubes-based polymerized high internal phase emulsion composite (CNT/polyHIPE) as sorptive phase in biological sample preparation. A micro-solid-phase extraction procedure (µSPE) was developed for trace fluoroquinolone (FQ) antimicrobials, namely Ciprofloxacin, Levofloxacin, Lomefloxacin, Moxifloxacin, Norfloxacin and Sparfloxacin, in human urine samples. PolyHIPEs modified by incorporation of different concentrations of nanotubes (0.2–0.8 wt %) were one-pot synthesized and applied in the packed-cartridge setting. The sorption affinity for the drugs was investigated in tap water and buffered aqueous solutions, demonstrating the key role of the nanotubes embedded in the polymer. The 0.5 wt % CNT composite was selected to develop a straightforward µSPE procedure directly in raw urine (1 mL sample), followed by HPLC-MS/MS. Targets were retained on the sorbent at near neutral pH and, after an aqueous washing (0.1 % v/v formic acid), eluted in a single-step with 4 % v/v ammonia aqueous solution (15 % v/v acetonitrile), thus combining extraction and clean-up. The method allowed accurate quantification of FQs, as evidenced by the recoveries (74–116 %, n = 3) obtained on blank pooled urine samples spiked with 40, 75, 150 µg L−1, accompanied by good inter-day precision (RSD < 14 %, n = 3). To confirm the applicability of the analytical method, some real-life blind samples were processed as a proof of concept.

How can contamination be prevented during laboratory analysis of atmospheric samples for microplastics?

Microplastics (MPs) in the air and indoor environments are of growing concern and have led to increased testing for MPs. This study draws attention to the quality and quantitative measures of MP studies by conducting laboratory experiments (on solutions, filters, and blank samples) that were rarely or were not adopted in the airborne and indoor MP literature. Experiments have been conducted to identify contaminations that may come from experimental procedures while determining MPs in the air samples. MPs in different matrices during experiments were counted and categorized by their shapes. Chemical characterization was performed by Raman Spectroscopy. Results showed that laminar flow is the best option over a fume hood or standard laboratory environment for detecting air MPs to reduce blank levels. Blue-green and Black-Grey were the dominant colors; fiber was the predominant type of MPs seen, and most of them fall under the size range from (1-1000µm) in different indoor environments and blanks. Common MPs seen were PP, PVA, PTFE, PVC, and HDPE. Thermal treatment of fresh unused filters at 450°C for 4h was effective as it reduced the MP count by 50%. Working solutions are mainly contaminated, and their pre-filtration is essential. The average deposition of MPs in blank samples during seven days was around 55 MPs. There is an urgent need for studies on developing quality control and quality assurance of airborne and indoor MPs. Hence, a standard protocol needs to be accepted; by harmonizing procedures, comparable results can be found, uncovering the correct levels of MP contamination, as required for risk assessment.

Enhanced thermal shock resistance of low‐carbon Al2O3‐C refractories via CNTs/MgAl2O4 whiskers composite reinforcement

AbstractThe CNTs/MgAl2O4 whiskers composite reinforcement was prepared by catalytic carbon‐bed sintering and added to low‐carbon Al2O3‐C refractories to enhance the thermal shock resistance of refractories. The effects of Ni(NO3)2·6H2O content on the phase and microstructure of CNTs/MgAl2O4 were investigated. The nano‐indentation technology was used to quantitatively evaluate the effect of CNTs/MgAl2O4 on the thermal shock resistance of low‐carbon Al2O3‐C refractories, and the toughening mechanism of CNTs/MgAl2O4 on refractories was further investigated. The results revealed that the inner and outer diameters of the CNTs were approximately 5.69 and 16.26 nm, respectively. The CNTs winded around interlocking structural MgAl2O4 whiskers with a high aspect ratio (&gt;100), which was beneficial to the dispersion of CNTs in the refractory matrix. The thermal shock resistance of low‐carbon Al2O3‐C refractories was significantly improved by adding 3.0 wt.% of CNTs/MgAl2O4 (named C3). The specific fracture energy of refractory matrix and residual strength ratio of C3 reached 141 N·m−1 and 39.2%, which were 29.4% and 97.0% higher than those of the blank sample (109 N·m−1 and 19.9%), respectively. This is because the refractory matrix was significantly reinforced by CNTs and MgAl2O4 whiskers, promoting the occurrence of “bridging” and “crack deflection” and the generation of microcracks in the refractory matrix.

Exploring the Influences of BaO Amount on the Wettability and Mechanical Behavior of Vitrified Bond Diamond Composites.

In recent years, the vitrified bond diamond grinding wheel has been applied widely in automotive, aerospace and machine tools of manufacturing industries. However, the main problems of low intensity and poor wettability between the vitrified bond and diamond abrasive limit its further application. In this study, BaO was added into the basic SiO2-B2O3-Al2O3-R2O vitrified bond system, and the impact of BaO on the wettability, thermal and mechanical behavior of vitrified bond and vitrified bond diamond composites was systematically discussed, respectively. The test indicated that when the vitrified bond containing BaO of 6 wt.% was sintered with diamond abrasive at 750 °C, a continuous barium feldspar phase transition layer between diamond abrasive and the bond was generated, which ameliorated the wet property of the bond-diamond abrasive. The contact angle varied from 59° on the blank sample to 35°, and the expansion coefficient changed from 6.24 × 10-6/K to 5.30 × 10-6/K. The Rockwell hardness and flexural strength of the vitrified bond diamond composites achieved the peaks of 117.5 MPa and 113.6 MPa, respectively, which increased by 20.2% and 16.5% compared with that of sample without the addition of BaO.

Development of a QuEChERS-HPLC-FLD Procedure for the Simultaneous Detection of Residues of Florfenicol, Its Metabolite Florfenicol Amine, and Three Fluoroquinolones in Eggs.

A method utilizing high-performance liquid chromatography-fluorescence detection (HPLC-FLD) has been developed and refined for the simultaneous detection of florfenicol (FF) and its metabolite florfenicol amine (FFA) along with three fluoroquinolone (ciprofloxacin (CIP), enrofloxacin (ENR), and sarafloxacin (SAR)) residues in different parts of eggs (whole egg, egg yolk, and egg albumen). The QuEChERS ("Quick, easy, cheap, effective, rugged, and safe") procedure utilized 0.1 M disodium EDTA solution, water, and acetonitrile as extractants; sodium sulfate, sodium chloride, and trisodium citrate as dehydrating salts; and N-propylethylenediamine and C18 as adsorbents. A dual-channel FLD method was utilized to analyze the target compounds using an XBridge BEH C18 chromatographic column (4.6 mm × 150 mm, 5 μm). The mobile phase was employed isocratically using a solution of 0.01 M sodium dihydrogen phosphate, 0.005 M sodium dodecyl sulfate, and 0.1% triethylamine (pH 4.8) in combination with acetonitrile at a ratio of 65:35 (V/V). The limits of detection (LOD) and quantification (LOQ) of the analytes ranged from 0.03 to 1.5 µg/kg and from 0.1 to 5.0 µg/kg, respectively. The recoveries of the analytes in the blank egg samples ranged from 71.9% to 94.8% when reference standard concentrations of the LOQ, half of the maximum residual limit (MRL), MRL, and twice the MRL were added. The parameters of the presented protocol were validated and subsequently applied to the analysis of real samples, demonstrating the applicability and reliability of the method.

Co@C synergistic alkali-catalyzed depolymerization of hydrolyzed lignin for the preparation of multifunctional ceramic additives

In this research endeavor, we report the successful synthesis of an aminosulfonic-based ceramic additive, HLDSA, was prepared by replacing part of phenol with HLDLP, a depolymerization product of hydrolysis lignin, through Co@C metal catalysts in the synergistic alkali-catalyzed depolymerization of hydrolysis lignin to achieve high-value lignin utilization. The preparation and application conditions of the depolymerized hydrolysis lignin HLDLP and its modified product HLDSA were studied, together with a brief analysis of their mechanism of action. During application of ceramic additive, the HLDSA showed a rather excellent dispersing and flexural strength performance, with a minimum slurry outflow time of 20.81 s and a maximum flexural strength of 2.79 MPa, which was a significant improvement over that of the blank sample (59.29 s and 1.77 MPa). Meanwhile, HLDSA was contrasted with other 8 ceramic additives that are widely available on the market. The application performance of HLDSA was also better than that other ceramic additives on the market, indicating that HLDSA has a promising application.

Analytical methods and experimental quality in studies targeting carbonyls in electronic cigarette aerosols.

We provide an extensive review of 14 studies (11 independent and three industry-funded) on emissions generated by Electronic Cigarettes (ECs), specifically focusing on the evaluation of carbonyls present in these emissions and emphasizing a meticulous evaluation of their analytical methods and experimental procedures. Since the presence of carbonyl by-products in EC aerosol is concerning, it is important to evaluate the reliability of emission studies quantifying these compounds by verifying their compliance with the following criteria of experimental quality: authors must 1) supply sufficient information on the devices and experimental procedures to allow for potentially reproducing or replicating the experiments, 2) use of appropriate puffing protocols that approach consumer usage as best as possible, 3) use of appropriate analytical methods and 4) usage of blank samples to avoid false positive detection. Outcomes were classified in terms of the fulfilment of these conditions as reliable in seven studies, partially reliable in five studies, and unreliable in two studies. However, only five studies used blank samples and six studies failed the reproducibility criterion. Carbonyl yields were far below their yields in tobacco smoke in all reproducible studies, even in the partially reliable ones, thus supporting the role of ECs (when properly tested and operated) as harm reduction products. This review highlights the necessity to evaluate the quality of laboratory standards in testing EC emissions to achieve an objective assessment of the risk profile of ECs.