Search results for: Woranuch Deelaman

Authors: Woranuch Deelaman, Chomsri Choochuay, Siwatt Pongpiachan, Danai Tipmanee

Abstract:

In this work, perform an analysis to identify the source of PAHs in particulate matter (PM). The five sizes are 0.1, 0.5, 1, 2.5, and 10 microns from Nakhon Ratchasima province, Thailand. Nakhon Ratchasima is a province in the northeastern part of Thailand. It has an area of 20,493 square kilometers and a forest area of 2,297,735 rai, making it the second largest area in the country. The major economies of Nakhon Ratchasima Province have an important structure, including the industrial sector. The agricultural sector and wholesale and retail trade accounted for 22.46 percent, 19.82 percent, and 14.91 percent, respectively. This study, we collected particulates using the Nano-sampler II sampling tool for a month. PM samples (n = 20) were collected in Tambon Suranari (14°52'05.6"N, 102°00'31.8"E) is a sub-district located in the Mueang district of Nakhon Ratchasima province. It is an important area consisting of community sites, educational institutions, universities, hospitals, religious places, and industrial areas. The samples collected from November 1, 2024 to November 30, 2024. Then, the PM samples were wrapped with aluminium foil and stored at −4 °C until the analysis.The PAHs were chemically extracted for eight hours using a Soxhlet extractor and internal standards (deuterated-fluorene (d10-Fl): phenanthrene, anthracene, fluoranthene, pyrene, 11 H-benzo[a]fluorene, 11 H-benzo[b]fluorene, chrysene; deuterated-perylene (d12-Per): benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a] pyrene, benzo[e]pyrene, indeno[1,2,3-cd]pyrene, dibenz[a,h]anthracene, and benzo[g,h,i]perylene using DCM as a solvent, and then analyzed 15 PAHs from the PM using a gas chromatograph-mass spectrometer (Shimadzu GCMS-QP, 2010 Ultra) in the selective ion monitoring mode. The sources of PAHs in Nakhon Ratchasima particulate matter were determined using a combination of multivariate descriptive statistics and diagnostic binary ratios of PAHs. The source of PAHs in particulate matter was identified using five diagnostic binary ratios of PAH isomer pairs: An/(An + Phe), Fluo/(Fluo + Pyr), B[a]A/(B[a]A + Chry), Ind/(Ind + B[g,h,i]P), and B[a]P/B[g,h,i]P. According to the diagnostic ratio, the majority of the PAHs found in the particulate matter samples came from pyrogenic sources, which include incomplete burning of biomass and petroleum. Additionally, multivariate descriptive statistics (principal components analysis (PCA)) were used to identify the source of 15 PAHs in the Nakhon Ratchasima sample of particulate matter. The results of the PCA identification of aromatic polycyclic hydrocarbons in PM show that incomplete combustion from the use of fuel is also a major source of aromatic polycyclic hydrocarbons in Nakhon Ratchasima province. In the future, we anticipate that the study will help the environmental planning management of Thailand's Nakhon Ratchasima province and many other nations.

Keywords: polycyclic aromatic hydrocarbons (PAHs), particulate matter (PM), diagnostic binary ratio, source apportionment

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Authors: Chomsri Choochuay, Woranuch Deelaman, Siwatt Pongpiachan, Danai Tipmanee

Abstract:

Particulate matter (PM) is essential for comprehending climate change, alleviating negative health impacts, and formulating air pollution management strategies. There isn't enough knowledge about the chemical processes and factors that affect the occurrence and development of particle formation events. This study looked at the number of PM in the air and how they were distributed in size in Phuket province, Thailand, during the dry season (November). it used a cascade impactor (Nanosampler II Model 3182 Specifications) with 47-mm quartz filters and a 40 L min–1 flow rate. Each sample was collected over a period of 120 hours, and then it was properly stored in individual petri slide plates before being placed in the refrigerator. This was done to ensure that the samples' chemical makeup was preserved until further analysis was required. The focus of our research is to find the source of PM in the sampling area, and polycyclic aromatic hydrocarbons (PAHs) have been used for identification and quantification. The Soxhlet extraction method performed the PAHs analysis. the first mixed the sample with an internal standard. it used dichloromethane (DCM) as the solvent and continued the extraction for 8 hours. Finally, it separated the PAHs from the solution using column chromatography, which got it ready for the next step of the analysis process. PAHs are non-polar organic molecules. the accomplished this by integrating in-port thermal desorption with gas chromatography/mass spectrometry (GC/MS). This method allows for the effective separation and identification of PAHs in complex environmental samples. By comparing the results from both techniques, we can gain deeper insights into the presence and concentration of these harmful compounds. For the source appointment of PM in ambient air in Phuket, it used the different forms of PAHs as indicators depending on their sources; there is a method for determining their origins known as the “diagnostic ratio.” The result shows the diagnostic ratios employed with their normally reported values for source points in this investigation. The comparisons of (Fluo/Fluo + Pry vs. An/An + Phe) and (B[a]A/B[a]A + Chry vs. Ind/Ind + B[g,h,i]P) showed that most PAHs come from things that people do. Therefore, human activities are the primary source of PAHs in PM samples. PMs that have been conducted in Phuket's ambient air pointed out that the major source of PAHs is thought to be the incomplete combustion of petroleum products, which is caused by the combustion of vehicular exhausts, as well as open burning of agricultural areas to prepare for the next crop season. According to this study, vehicle exhaust and biomass burning are the main sources of PAHs in Phuket's air. This implies that reducing emissions from these sources is crucial for enhancing air quality. Implementing stricter regulations on vehicle emissions and promoting cleaner combustion practices could be effective strategies for mitigating this issue.

Keywords: particulate matter (PM), polycyclic aromatic hydrocarbons (PAHs), air pollutions, source appointment

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Authors: Sarekha Woranuch, Rangrong Yoksan

Abstract:

Active packaging has been developed based on the incorporation of certain additives, in particular antimicrobial and antioxidant agents, into packaging systems to maintain or extend product quality and shelf-life. Ferulic acid is one of the most effective natural phenolic antioxidants, which has been used in food, pharmaceutical and active packaging film applications. However, most phenolic compounds are sensitive to oxygen, light and heat; its activities are thus lost during product formulation and processing. Grafting ferulic acid onto polymer is an alternative to reduce its loss under thermal processes. Therefore, the objectives of the present research were to study the thermal stability of ferulic acid after grafting onto chitosan, and to investigate the possibility of using ferulic acid-grafted chitosan (FA-g-CTS) as an antioxidant for active biodegradable packaging film. FA-g-CTS was incorporated into biodegradable film via a two-step process, i.e. compounding extrusion at temperature up to 150 °C followed by blown film extrusion at temperature up to 175 °C. Although incorporating FA-g-CTS with a content of 0.02–0.16% (w/w) caused decreased water vapor barrier property and reduced extensibility, the films showed improved oxygen barrier property and antioxidant activity. Radical scavenging activity and reducing power of the film containing FA-g-CTS with a content of 0.04% (w/w) were higher than that of the naked film about 254% and 94%, respectively. Tensile strength and rigidity of the films were not significantly affected by adding FA-g-CTS with a content of 0.02–0.08% (w/w). The results indicated that FA-g-CTS could be potentially used as an antioxidant for active packaging film.

Keywords: active packaging film, antioxidant activity, chitosan, ferulic acid

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Authors: Sarekha Woranuch, Rangrong Yoksan

Abstract:

Chitosan is a derivative of chitin, which is a second most naturally abundant polysaccharide found in crab shells, shrimp shells, and squid pens. The applications of chitosan in pharmaceutical, cosmetics, food and packaging industries have been reported owing to its general recognition as safe, excellent biodegradability and biocompatibility, as well as ability to form films, membranes, gels, beads, fibers and particles. Nevertheless, chitosan is an amino polysaccharide consisting of strong inter- and intramolecular hydrogen bonds which limit its solubility in neutral pH water resulting in restricted utilization. Chemical modification is an alternative way to impede hydrogen bond formation. The objective of the present research is to improve water solubility and antioxidant activity of chitosan by grafting with ferulic acid. Ferulic acid was grafted onto chitosan at the C-2 position via a carbodiimide-mediated coupling reaction. Different mole ratios of chitosan to ferulic acid (i.e. 1.0:0.0, 1.0:0.5, 1.0:1.0, 1.0:1.5, 1.0:2.0, and 1.0:2.5) and various reaction temperatures (i.e. 40, 60, and 80 °C) were used. The reaction was performed at different times (i.e. 1.5, 3.0, 4.5, and 6.0 h). The obtained ferulic acid-grafted chitosan was characterized by FTIR and 1H NMR technique. The influences of ferulic acid on crystallinity, solubility and radical scavenging activity of chitosan were also investigated. Ferulic acid grafted chitosan was successfully synthesized as confirmed from (i) the appearance of FTIR absorption band at 1517 cm-1 belonging to C=C aromatic ring of ferulic acid and the increased C–H stretching band intensity and (ii) the appearance of proton signals at δ = 6.31-7.67 ppm ascribing to methine protons of ferulic acid. The condition in which the reaction temperature of 60°C, reaction time of 3 h and the mole ratio of chitosan to ferulic acid of 1:1 gave the highest ferulic acid substitution degree, i.e. 0.37. The resulting ferulic acid grafted chitosan was soluble in water (1.3 mg/mL) due to its reduced crystallinity as compared with chitosan and also exhibited 90% greater radical scavenging activity than chitosan. The result suggested the utilization of ferulic acid grafted chitosan as an antioxidant material.

Keywords: antioxidant property, chitosan, ferulic acid, grafting

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