Harmful Chemical Research Articles

Immobilization of silver-loaded graphene oxide (Ag-GO) on canvas fabric support for catalytic conversion of 4 nitrophenol.

Due to the rising human population and industrialization, harmful chemical compounds such as 4-nitrophenol (4-NP) and various dyes are increasingly released into the environment, resulting in water pollution. It is essential to convert these harmful chemicals into harmless compounds to mitigate this pollution. This research focuses on synthesizing a novel heterogeneous catalyst using modified canvas fabric (CF) decorated with silver metal nanoparticles on graphene oxide nanosheets (Ag-GO/CF). The process involves coating the fabrics (CF) with graphene oxide (GO) nanosheets through sonication. Subsequently, silver nanoparticles are deposited in situ and reduced on the GO surface, resulting in the formation of the Ag-GO/CF composite. Various physicochemical characterizations were conducted to examine the interfacial interactions between CF, GO, and Ag nanoparticles. The catalytic activity of the nanocomposite was assessed by hydrogenating 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) in the presence of sodium borohydride (NaBH4). The results showed that the 10%Ag-5%GO/CF with a surface of 6 cm2 (3 × 2 cm) exhibited the highest catalytic activity, achieving a reduction efficiency of over 96% in 5 min. The 4-NP reduction reaction rate was well-fitted with a pseudo-first-order kinetics model with an apparent reaction rate constant (Kapp) of 0.676min-1. Furthermore, the Ag-GO/CF composite demonstrated remarkable stability over successive cycles, with no noticeable decrease in its catalytic activity, suggesting its promising application for long-term chemical catalytic processes. This synthesized composite can be easily added to and removed from the reaction solution while maintaining high catalytic performance in the reduction of 4-NP, and it could be beneficial in avoiding problems related to powder separation.

The bench to community initiative: community-based participatory research model for translating research discoveries into community solutions.

The BCI program was established to understand sociocultural determinants of personal care product use, evaluate the biological impact of endocrine disrupting chemicals, and develop community interventions. The three pillars of the program include research, outreach and engagement as well as advocacy activities. The research pillar of the BCI includes development of multidisciplinary partnerships to understand the sociocultural and biological determinants of harmful chemical (e.g., endocrine disrupting chemicals) exposures from personal care products and to implement community interventions. The outreach and engagement pillar includes education and translation of research into behavioral practice. The research conducted through the initiative provides the foundation for advocacy engagement with applicable community-based organizations. Essential to the mission of the BCI is the participation of community members and trainees from underrepresented backgrounds who are affected by breast cancer disparities. Two behavioral interventions will be developed building on prior research on environmental exposures with the focus on personal care products including findings from the BCI. In person and virtual education activities include tabling at community events with do-it-yourself product demonstrations, Salon Conversations-a virtual platform used to bring awareness, education, and pilot behavior change interventions, biennial symposiums, and social media engagement. BCI's community advisory board members support activities across the three pillars, while trainees participate in personal and professional activities that enhance their skills in research translation. This paper highlights the three pillars of the BCI, lessons learned, testimonies from community advisory board members and trainees on the impact of the initiative, as well as BCI's mission driven approaches to achieving health equity.

Determination of formaldehyde in fresh seafood from Cambodia’s local market

Seafood is a rich nutritional food. It provides a healthy source of protein, minerals, and vitamins. To extend shelf life, formalin was added to seafood. Formaldehyde, or formalin, is an organic compound and has been widely used as a preservation food. The concentration of formaldehyde was considered according to food safety and human health. The aim of this study was the identification and determination of formaldehyde in fresh seafood from Cambodia’s local market. The three samples of seafood—shrimp, squid, and short mackerel were analyzed using the UV spectrophotometry technique where the absorbance of formaldehyde was detected at 412 nm. Therefore, squid contains formaldehyde in the range of 3.199-0.164 mg/kg, shrimp 0.174-0.134 mg/kg, and short mackerel 0.168-0.140 mg/kg, following the findings of the formaldehyde investigation. The accuracy was presented as a recovery percentage. It exceeded 95%; that was between 80-120%, which represents good accuracy. In conclusion, the presence of formaldehyde in seafood and other foods should be properly investigated and monitored to detect this harmful chemical.

Analytical monitoring of harmful chemicals in the air of the working area of main pipeline transport facilities for oil and petroleum products

RATIONALE: At main pipeline transport facilities, the entry of harmful chemicals into the air of the working area can negatively affect the body of workers. The absence in the existing regulatory documents of clearly formulated criteria for the selection of specific harmful chemical compounds to control their content, especially if they are a multicomponent mixture, introduces certain difficulties in identifying pollutants in the air of the work area. The presence of criteria will allow the employer to correctly draw up a production program, the frequency of laboratory tests to obtain more objective and reliable information about the potential harmful effects of chemicals on workers and timely take measures to prevent their negative effects. AIM: Justification of the list of harmful substances for analytical monitoring of their content in the air of the working area of main pipeline transport facilities for oil and petroleum products. MATERIAL AND METHODS: Qualitative and quantitative analysis of the air in the working area was carried out at 12 oil pumping stations and 5 oil product pumping stations located in Russia. RESULTS: Using chromatography-mass spectrometry, the composition of the gas-air environment formed as a result of oil evaporation was determined, which made it possible to determine a list of harmful chemicals for further planned analytical monitoring of their content in the air of the working area.CONCLUSION: Sampling should be carried out in places with the highest probability of gas emissions into the air. When transporting oil, it is necessary to establish strict analytical control at workplaces over the content of aliphatic saturated hydrocarbons C2-C10, dihydrosulfide mixed with hydrocarbons, benzene in the air, when pumping petroleum products - benzene, gasoline or kerosene, i.e. depending on the type of petroleum product transported.

Bioassay predictive values for chemical health risks in drinking water

Bioanalytical tools can be used for assessment of the chemical quality of drinking water and its sources. For water managers it is important to know the probability that a bioassay response above an established health-based ‘effect-based trigger value’ (EBT) indeed implies a harmful chemical (mixture) concentration. This study presents and applies a framework, based on Bayes’ theorem, to derive such risk probabilities for bioassay responses. These were evaluated under varying (in silico) chemical mixture concentrations relevant to drinking water (sources), with toxicity data for six in vitro assays from the ToxCast database. For single chemicals and in silico mixtures, the negative predictive value (NPV) was 100 % for all assays. For water managers, this means that when a bioassay response is below the EBT, a chemical risk is reliably absent, and no further action is required. The positive predictive value (PPV) increased with increasing chemical concentrations (2 µg/L) up to 40–80 %, depending on the assay. For in silico mixtures of increasing numbers of chemicals, the PPV did not increase until higher sum concentrations (>2–10 µg/L). Hence, the ability to accurately signal a harmful chemical (mixture) using bioassays will be lowest for highly diverse, low-concentration chemical mixtures. For water managers, this means in practice that further investigations after an EBT exceedance will, in many cases, not reveal chemicals at harmful concentrations. A solution offered is to increase the trigger value for positive responses to achieve a higher PPV and maintain the EBT for negative responses to ensure an optimal NPV.

(Invited) Sustainable Recycling of Metals from Solar Cells

The share of solar energy is increasing worldwide, leading to a widespread use of solar panels. Knowing that the 80 Mt of waste solar panels will be produced by 2050, sustainable processes must be designed in order to deal with the inevitable increase of waste solar cells in the coming years.The main advantage associated with recycling is to avoid the inevitable dispersion of hazardous materials in the environment occurring when the solar cells are landfilled. It also reduces the need for primary mineral resources and may reduce the supply risk for important components like silicon wafers, for which the production is concentrated in a few countries. The recycling process applied plays a major role to allow reducing the carbon footprint of solar cells, advocating in favour of sustainable practices for solar cells recycling.Mono-crystalline solar cells representing 90% of the market, it is therefore this kind of solar cells that are more likely to reach their end-of-life soon. Mono-crystalline solar cells are made of an aluminium frame surrounding the solar module. Underneath a glass layer, layers of ethylene vinyl acetate (EVA) encapsulate the solar cell. The solar cell in itself is made of a silicon wafer with aluminium and silver electrode as well as a silicon nitride anti-reflective coating. Recycling of the metals, particularly silver, is the main economic driver for solar cells recycling.Recycling mono-crystalline solar cells involves a mechanical removal of the aluminium frame and the junction box prior to removal of the glass and EVA layers. Different process were evaluated to get rid of EVA. Solvent-assisted dissolution allowed EVA dissolution but it requires the use of harmful solvents and often leads to breakage of the solar cell. Pyrolysis allows to recover the wafer intact while removing the glass and polymers layers. Provided that the thermal treatment is applied under an inert atmosphere, EVA decomposition leads to relatively non-toxic chemicals such as acetic acid. Recent developments include laser assisted would lead to efficient and straightforward removal of EVA.The removal of metals from the solar cells involves the use of harsh chemicals such as hydrofluoric acid for the removal of silicon nitride, nitric acid to solubilise silver and sodium hydroxide for the dissolution of aluminium. Recently, the use of aqueous brines was introduced to recover silver and aluminium from solar cells. A green and re-usable oxidising agent such as iron(III) chloride can be used to oxidise and dissolve silver, as evidenced in Figure 1, which shows a solar cells before (up) and after (down) etching, revealing the removal of the white silver lines.Using water as a solvent, silver dissolution is impossible due to the low chloride content. By increasing the chloride content, oxidation of silver and its dissolution becomes possible due to the formation of iron-chloride and silver-chloride complexes which have a different redox behaviour and a higher solubility. Overall, silver is completely dissolved in about 10 minutes without using any acids or harmful chemical. Silver can be easily recovered by precipitation or cementation, while the oxidising agent can be regenerated using oxygen from air or via electrolytic means. The objective of this presentation is to give an overview of the current recycling options and provide some guidance on the best and more sustainable practices for the complete recycling of solar cells. The choice is guided by techno-economic analysis and life cycle assessment as well as experimental demonstration of the recycling on real waste solar cells. Figure 1

Amine-Impregnated Dendritic Mesoporous Silica for the Adsorption of Formaldehyde.

To adsorb and remove formaldehyde, which is a harmful volatile organic chemical (VOC) detected indoors, an alkylamine was introduced into the substrate as a formaldehyde adsorbent. In this study, Tetraethylenepentaamine (TEPA) was introduced into the mesoporous silica using the amine impregnation method. Since the impregnated alkylamine can block the pores of the silica substrate, the pore size and pore volume are very important factors for its use as a substrate for an adsorbent. Focusing on the substrate's pore properties, Santa Barbara Amorphous-15 (SBA-15) was chosen as a conventional one-dimensional pore-structured mesoporous silica, and dendritic mesoporous silica (DMS) as a three-dimensional pore-structured mesoporous silica. To 1 g each of silica substrate DMS and SBA-15, 0, 0.5, 1.5, and 2.5 g of TEPA were introduced. A fixed concentration and amount of formaldehyde gas was flowed through the adsorbent and then the adsorbent was changed to the 2,4-Dinitrophenylhydrazine (2,4-DNPH) cartridge to adsorb the remaining formaldehyde. According to the methods recommended by the World Health Organization (WHO) and National Institute for Occupational Safety & Health (NIOSH), the formaldehyde captured by 2,4-DNPH was analyzed using high-performance liquid chromatography (HPLC). A comparison of DMS and SBA-15 in the amine impregnation method shows that not only surface area, but also large pore size and high pore volume, contribute to the formaldehyde adsorption ability.

4-Nitrophenol reduction and antibacterial activity of Ag-doped TiO2 photocatalysts.

Water contamination by organic pollutants is a serious environmental problem. 4-Nitrophenol (4-NP) is a potentially harmful chemical, which is commonly present in industrial effluents and can severely damage human health. Photocatalytic reduction of hazardous 4-NP by nano-sized materials to produce 4-aminophenol (4-AP), which is a commercially valuable product, is a promising alternative as the process is framed within the circular economy. In this context, Ag-doped TiO2 (AT) catalysts were synthesized by liquid impregnation and reduction techniques, and their structure, morphology, elemental composition, textural, and light absorption properties were evaluated by XRD, Raman spectroscopy, SEM, TEM, EDS, BET, and DRS spectroscopy. AT catalysts exhibited an enhanced photocatalytic reduction of 4-NP into 4-aminophenol (4-AP) in the presence of NaBH4. Among the tested catalysts, AT21 prepared by a simple aqueous reduction method showed the highest activity reaching about 98% 4-NP reduction within 10min. Antibacterial tests of these catalysts against Bacillus subtilis, Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa revealed that AT21 also exhibited the lowest minimum inhibitory concentration, suggesting that it has the strongest antibacterial activity. These findings suggest that AT21 catalyst with improved catalytic and antibacterial properties can potentially be utilized for the remediation of 4-NP-contaminated water environment.

Association of organophosphate flame retardants with all-cause and cause-specific mortality among adults aged 40 years and older

The longitudinal associations of urinary concentrations of diphenyl phosphate (DPHP), bis(2-chloroethyl) phosphate (BCEP), and bis(1,3-dichloro-2-propyl) phosphate (BDCPP) with all-cause, cardiovascular, and cancer mortality in a population of adults aged 40 years and older are still unclear. A total of 3238 participants were included in this cohort study. Urinary BCEP levels were positively associated with all-cause mortality and cardiovascular mortality. Specifically, a logarithmic increase in BCEP concentration was related to a 26 % higher risk of all-cause mortality and a 32 % higher risk of cardiovascular mortality. No significant associations were observed for DPHP and BDCPP in relation to mortality. Doseresponse analysis confirmed the linear associations of BCEP with all-cause and cardiovascular mortality and the nonlinear inverted U-shaped association between DPHP exposure and all-cause mortality. Notably, the economic burden associated with BCEP exposure was estimated, and it was shown that concentrations in the third tertile of BCEP exposure incurred approximately 507 billion dollars of financial burden for all-cause mortality and approximately 717 billion dollars for cardiovascular mortality. These results highlight the importance of addressing exposure to BCEP and its potential health impacts on the population. More research is warranted to explore the underlying mechanisms and develop strategies for reducing exposure to this harmful chemical.

Differential scanning calorimetry as a tool to assess the oxidation state of cold-pressed oils during shelf-life

AbstractCold-pressed oils are highly prone to the peroxidation process, which causes a rapid decline in quality. Thus, there is a need to develop instrumental methods instead of conventional chemical analysis consuming large quantities of harmful chemicals. Differential scanning calorimetry (DSC) is a valuable analytical tool for assessing the oxidative stability of oils. Cold-pressed flaxseed, camelina and hemp seed oils from different cultivars, which had been stored for six months in room conditions under natural light exposure, were tested. Chemical methods for measuring changes in oxidative stability during storage of oils included determination of peroxide value (PV), p-Anisidine value (p-AV), total oxidation value (TOTOX) value and acid value (AV). Parameters like oxidation induction time (OIT) in isothermal mode (120, 140 °C) and onset temperature (Ton) in non-isothermal mode (heating rate 2, 5 °C/min) were established from DSC curves. Data for OIT and Ton plotted against time showed a strong, significant (p ≤ 0.05) descending trend for all oils. However, flaxseed and hempseed oils revealed a more rapid deterioration during storage compared to camelina seed oils. All DSC results showed promising repeatability of the oxidative characteristics for three types of cold-pressed oils, regardless of their origins in different cultivars. However, the most suitable for monitoring the deteriorative changes in oils during storage was the isothermal test carried out at a temperature of 120 °C, for which the correlations with chemical indicators (PV, p-AV, TOTOX) were highly significant (p ≤ 0.0001). Linear discriminant analysis (LDA) based on the DSC results revealed, that the first discriminating function significantly separated the fresh oils from stored oils. The study showed that, based on a starting point defined for fresh oils, the DSC technique can be used to effectively and ecologically monitor the deterioration of oils by oxidation, instead of harmful chemical analyses.

An Oral Polyphenol Host-Guest Nanoparticle for Targeted Therapy of Inflammatory Bowel Disease.

Inflammatory bowel disease (IBD) is a global public health challenge that affects millions of people. Current medical treatments for IBD are not fully effective and may cause undesirable side effects on patients. Thus, there is an urgent need for safe, simple, and efficacious strategies to treat IBD in clinical settings. Here, we develop an oral polyphenol nanoparticle (PDT) by assembling dexamethasone sodium phosphate (DSP)-loaded poly-β-cyclodextrin with tannic acid via host-guest interactions for treating IBD. This one-step assembly process is rapid (within 10 s), reproducible, and free of harmful chemical agents, which can facilitate its clinical translation. PDT is negatively charged due to the three components, which enable it to specifically target the positively charged inflamed colonic mucosa through electrostatic attraction, thus localizing the drug at the inflamed site to reduce systemic exposure and side effects. Furthermore, PDT exhibits a strong reactive oxygen species (ROS)-scavenging ability derived from the tannic acid component, which can alleviate ROS-mediated inflammatory responses and ameliorate IBD symptoms. Compared with free DSP, PDT demonstrates sustained DSP release behavior in vitro and in vivo, as well as enhanced therapeutic efficacy in a colitis mouse model. These results suggest that PDT might be a potential therapeutic agent for the treatment of IBD. Moreover, this facile polyphenol host-guest assembly strategy may provide a promising drug-delivery platform for treating various diseases STATEMENT OF SIGNIFICANCE: To develop safe and effective treatments for inflammatory bowel disease (IBD), we have designed an oral polyphenol nanoparticle (PDT) using the host-guest assembly of dexamethasone sodium phosphate (DSP)-loaded poly-β-cyclodextrin with tannic acid. Through in vitro and in vivo experiments, PDT has demonstrated remarkable inflammation-targeting, ROS-scavenging, and anti-inflammatory properties, along with sustained release of DSP. Moreover, in an IBD mouse model, PDT has shown significantly improved therapeutic efficacy compared to free DSP. The host-guest assembly strategy employed for PDT is noteworthy for its rapidity, reproducibility, and safety due to the absence of harmful chemicals, holding great promise for designing a diverse range of nanomedicines customized for treating various diseases.

Analysis of risk factors for the formation of functional disorders 
 of the respiratory system in metalworking employees

Introduction. Employees of the main occupations of metalworking production are exposed to a complex of harmful production and non-production factors contributing to the formation of bronchopulmonary pathology. The identification of priority factors leading to the development of diseases of the respiratory system is important in order to develop methods of effective prevention of bronchopulmonary diseases in employees of the metalworking industry. 
 Materials and methods. As part of the cross-sectional study, the medical and social aspects and the health status of three hundred metalworking employees were studied. A hygienic assessment of the factors of the working environment and the labour process was carried out. The results of the study were statistically processed using the Statistica 10 software.
 Results. There was a discrepancy in the number of workers with an established diagnosis of bronchopulmonary disease and the number of workers complaining from the respiratory system and having physical and spirometric disorders. Workers were established to be exposed to a complex of harmful chemicals of hazard classes 1–4, having an irritating, carcinogenic, sharply directed mechanism of action on the human body (classes 2–3.2) and aerosols of predominantly fibrogenic action (class 2). The harmful chemical factor affecting metalworking employees did not have a significant effect on the formation of functional disorders of the respiratory system. The priority risk factor for the development of bronchopulmonary pathology in metalworking employees is the use of tobacco smoking products.
 Limitations. The study has regional (Saratov region) and occupational (metalworking employees) limitations.
 Conclusion. The priority risk factor for the development of bronchopulmonary pathology is the use of smoking tobacco products, and the impact of a harmful chemical factor that had an insignificant effect on the formation of functional disorders of the respiratory system of metalworking employees.

Are Malaysians Aware? The Consumer Awareness on Harmful Chemicals in Household Products

Detergents, cosmetics, and food are just a few examples of everyday products and household items that include chemicals. Chemical-free items are difficult to produce since chemicals are necessary for some performances. Despite emphasising their uses, it cannot be denied that chemicals negatively impact human health and the environment. However, because chemicals are a part of our daily lives, we become so accustomed to them that we often disregard and forget about their negative effects. This study will examine consumer knowledge of dangerous chemical items. In this research, the factors that influence health awareness will be discussed. The study will examine two factors affecting the consumers' awareness: The information factor and the personal factor. The information factor includes commercial sources, neutral sources, and social sources. The personal factors are interest in health information and attitudes toward harmful chemicals. The research was done by collecting feedback from 187 youth aged 18 to 40 in Malaysia who are now managing a household. An online questionnaire with a 5-Likert rating scale is used to collect the data. The result of the study indicated that neutral sources, social sources, interests and attitudes will affect the consumer awareness of the harmful household chemical. On the other hand, commercial sources will not affect youth awareness of harmful household chemical products. This study can understand Malaysians’ awareness level towards harmful chemicals and thus find effective ways to increase the awareness among Malaysians.

Barrier effect of insulation against harmful chemical substances according to the wall surface construction of layered building materials

Energy consumption by buildings can be reduced by increasing thermal efficiency by improving insulation. Phenolic foams (PFs) are stable and economical insulation materials with low thermal conductivity. However, chemical-containing building materials can pollute indoor air in residential spaces. Indoor air quality, related to PF construction in interior walls, was investigated using discharge chamber tests and a test bed simulating construction. Concentration changes of harmful chemicals following insulation construction in the test bed and empirical research results can guide legal management standards for indoor air quality in terms of insulation materials and the effective construction of insulation materials.

A colorimetric sensor with dual-ratio and dual-mode for detection of nicotine in tobacco samples.

Nicotine (NIC) is a harmful substance, drug, pesticide and chemical that is widely found in tobacco. It has carcinogenic, teratogenic and neurotoxic effects that have raised serious concerns. Herein, a colorimetric sensor with dual-ratio and dual-mode for the detection of NIC in tobacco samples was reported. The localized surface plasmon resonance signals of gold nanoparticles (AuNPs) and AuNPs-NIC are used as dual-ratio signals. The absorbance ratio of NIC to AuNPs or the absorbance ratio of NIC to AuNPs-NIC and the wavelength shift value of AuNPs-NIC are applied as dual-mode. Transmission electron microscopy, energy dispersive spectroscopy, dynamic light scattering spectroscopy, ultraviolet-visible spectrophotometry, cyclic voltammetry, and potentiostatic methods were used to characterize the sensor. Further analysis of NIC was conducted through morphological fitting and theoretical calculations. Under optimal conditions, the sensor shows a wide linear range of 5-500 μM. The detection limits for NIC are 2.48 μM, 1.63 μM and 1.34 μM, respectively. The experimental result shows that the dual-ratio signal of AuNPs and AuNPs-NIC has good selectivity and sensitivity, and can effectively reduce the interference of impurities on NIC detection. And the dual-mode of detection for NIC improves the accuracy and comparability of the result significantly. In addition, the proposed sensor was also applied to test NIC in tobacco samples with satisfactory recovery.

Optimal Decisions on Harmful Chemical Limits in Consumer Goods within an Acceptable Risk Level

Standard limits for harmful chemicals in consumer goods are important for consumer safety and the development of relevant industries. This paper proposes a method for determining content limits of chemicals in consumer goods by extending the “as low as reasonably practicable” (ALARP) principle by adding the impact of price and cost changes. While giving due consideration to the price and cost factors of consumer goods, this method derives such limits by measuring “acceptable consumer risk level” on the demand side and “industrial tolerance to chemical limits” on the supply side to obtain the ALARP area. Through a combination of functional relations between different factors and chemical limits, including consumer welfare, producer welfare, and external cost, a general chemical limit decision model can be created for the determination of the general limits of chemicals. This research provides a new methodology for studying decisions on chemical limits by considering consumer and industry affordability. In the final part of this paper, the feasibility and effectiveness of the proposed method are verified based on data of Bisphenol A used in the production of polycarbonate (PC) toys; the data were obtained from enterprise surveys and consumer questionnaires. Through our method, in this paper, a more suitable determination of harmful chemical substances can be obtained.

Toward a greener approach to detect inorganic arsenic using the Gutzeit method and X-ray fluorescence spectroscopy.

Inorganic arsenic is a carcinogen repeatedly found in water and foods threatening global human health. Prior work applied the Gutzeit method and X-ray fluorescence spectroscopy to quantify inorganic arsenic based on a harmful chemical, i.e., mercury bromide, to capture the arsine gas. In this project, we explored silver nitrate as an alternative to mercury bromide for the capture and detection of inorganic arsenic. To compare the performance of mercury bromide and silver nitrate, two standard curves were established in the range from 0 to 33.3 µg/L after optimization of reaction conditions such as the quantity of reagents and reaction time. Our result shows silver nitrate-based standard curve had a lower limit of detection and limit of quantification at 1.02 µg/L and 3.40 µg/L, respectively, as compared to the one built upon mercury bromide that has limit of detection of 4.86 µg/L and limit of quantification of 16.2 µg/L. The relative higher sensitivity when using silver nitrate was contributed by the less interfering elements for X-ray fluorescence analysis and thus lower background signals. A commercial apple juice was studied for matrix inference, and the results show 85%-99% recoveries and 7.4%-24.5% relative standard deviation. In conclusion, we demonstrated silver nitrate is a better choice in terms of safety restrictions and detection capability at lower inorganic arsenic concentrations.

Elemental analysis of talcum powder using spectroscopic techniques

Talcum powder is a much more useable cosmetic in many parts of the globe. It is responsible for harmful chemical poisoning such as it is likely to promote cancer symptoms. Due to the dangerous effect of harmful chemicals, talcum powder was analyzed. We report the elemental composition of the talcum powder using spectroscopic techniques, plasma has been produced at an atmospheric air pressure using a Q-switch (1064 nm) Nd: YAG laser with a laser intensity of 1.9 × 1011 W/cm2, 10 Hz repetition rate, and 5 ns pulse duration. From the spectroscopic analysis of the recorded spectra of plasma, we have detected Ca, Mg, Cr, Na, Sr, Li, and H. electron temperature (Te) has been calculated using the Boltzmann plot method while electron number density (Ne) calculated using the Stark Broadening profile method. Besides that, we have studied the behavior of Te and Ne as a function of delay time. It was observed the decreasing trends of the plasma parameters with delay time. The Inverse Bremsstrahlung (IB) absorption co-efficient and its fluctuation over delay time were also determined.We have also studied the elemental composition of the talcum powder using CF-LIBS, AAS, and EDX techniques. It was also noticed the maximum concentration of Ca in talcum powder using CF-LIBS, AAS, and EDX techniques.

Strategic management of harmful chemicals produced from pyrolysis of plastic cup waste using CO2 as a reaction medium

Disposable plastic cup has been expensively used in our daily life due to its versatility, usability, and affordability. However, the mass increase in plastic cup waste (PCW) becomes detrimental environmental issues because the current plastic disposal process could be a vector for microplastics and hazardous compounds. In this study, an environmentally benign disposal and valorization process of PCW was suggested. In particular, pyrolysis of PCW was performed using a greenhouse (CO2) as a reaction medium. The thermal degradation of PCW produced hazardous benzene derivatives because PCW was made of polyethylene terephthalate. The harmful aromatic compounds (benzene derivatives) were detoxified by means of syngas production (H2 and CO) in the presence of a Co catalyst. Effects of CO2 and Co catalyst resulted in conversion of more than 95 % of toxic chemicals, benzene derivatives, into syngas at 700 ˚C. CO2 also effectively suppressed a deactivation of Co catalyst because gas phase reactions between CO2 and benzene derivatives mitigated (hydro)carbon formations that can be deposited on the catalyst surface. Thus, this study proposed that CO2-assisted catalytic pyrolysis is a promising approach to convert disposable plastic container and CO2 into value-added products with mitigation of harmful chemical production.

Evaluation of a GC-MS method for benzyl chloride content in processed food, meats, and marine products distributed in Korea.

Benzyl chloride is a harmful chemical that contaminates air, water, and food. A static headspace GC-MS method for determining benzyl chloride in food was developed and validated. Two food matrices (fat/oil and chicken) were used for method validation. Sample preparation involved ultrasonication extraction and purification (syringe filtration). Linearity (R 2) was > 0.99, accuracy ranged from 86.91% to 110%, the limit of detection was 0.04-0.17mg/kg, and the limit of quantification was 0.13-0.52mg/kg. Recovery varied from 88.19% to 111.77%, and precision ranged from 0.10% to 1.17% in intraday and interday analyses. Among 102 food items (oils, fats, meat, marine, and egg products) distributed in Korea, benzyl chloride was only detected in six of the marine products. The validated analytical method can be used for routine monitoring of benzyl chloride residues in food and thereby prevent the human health risks associated with the consumption of food contaminated with this chemical.