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The sapu-sapu plant (Baeckea frutescens L.) is widespread in the Bangka Belitung Islands Province, thriving in sandy areas such as beaches and highlands with less fertile soil. This study aimed to determine the optimal harvest time for sapu-sapu leaves to obtain essential oils' highest yield and most desirable characteristics. The research focused on the duck-type sapu-sapu leaves, using five variations of harvest time (coded as A1, A2, A3, A4, and A5, representing leaves harvested at 1, 2, 3, 4, and 5 months of growth, respectively). Essential oil extraction was performed using the steam distillation method. The resulting oils were then analyzed using Gas Chromatography-Mass Spectrometry (GC-MS) to determine their chemical composition. The results showed that sample A1 (1-month growth) produced the highest essential oil yield at 0.74% (w/w). This sample also exhibited the most optimal essential oil characteristics: clear yellow color, characteristic sapu-sapu odor, warm bitter taste, solubility in 96% ethanol at 1:13, specific gravity of 0.8863 g/mL, optical rotation of (+) 10.28°, and refractive index of 1.474. GC-MS analysis revealed that the main compounds in the A1 sample were α-pinene (43.84%), β-pinene (13.56%), and 1,8-cineol (24.26%). The study concluded that while the variation in harvest time of sapu-sapu leaves did not significantly affect the yield, characteristics, or composition of the essential oils, there were slight differences in yield and color. Sample A1, representing the youngest leaves, produced the most optimal results.

Mesoporous silica nanoparticles (MSNs) have drawn significant attention due to their exceptional properties and diverse range of applications, particularly in nanomedicine. The distinctive properties of MSNs, such as their high surface area, tunable pore size, and versatile surface chemistry, make them ideal candidates for various biomedical applications. This review aims to present a detailed understanding of MSNs, from synthesis and characterization to their versatile applications in biomedicine, highlighting their significant potential in advancing healthcare technologies. The synthesis methods for MSNs were comprehensively discussed, emphasizing the influence of parameters like solvent, base, alkoxysilane concentrations, and template surfactants on the size and shape of the nanostructures. Different types of MSNs, including MCM-41, SBA-15, KIT-6, and hollow MSNs, are discussed, along with their synthesis protocols and unique characteristics. The review also covers various spectroscopic techniques, such as XRD, XPS, FTIR, NMR, and fluorescence spectroscopy, which are crucial for characterizing MSNs. Furthermore, the biomedical applications of MSNs are highlighted, demonstrating their potential in drug delivery systems, imaging, and diagnostics. The review concludes with a discussion of the future perspectives and challenges in the field, providing insights into potential developments and the prospects for clinical translation.

The robustness evaluation of the acid number analysis method in fish oil was carried out to see the effect of the type of ethanol used as a solvent in the titration process. The types of ethanol used in this study were pro analysis grade, pharma and food grade, and technical grade. The acid number values (mgKOH/g) in fish oil with various solvents obtained were 2.3955±0.3211 for pro analysis grade; 2.7932±0.2983 for pharma and food grade; 2.7812±0.3362 for technical grade 1; 2.7031±0.3405 for technical grade 2. The acid number for all types of ethanol has a value that is in accordance with the requirements of SNI 8467: 2018 where the acid number value must be less than 3 mgKOH/g. However, if the measurement uncertainty value is included in the calculation, only the pro analysis grade ethanol solvent has an acid number value that is in accordance with the requirements of SNI. The results of the ANOVA test also showed that there was a significant difference in the variation of ethanol types for determining acid numbers because the calculated F value (13.9004) was greater than the F table (3.0984). Therefore, the solvent that must be used in the method of determining acid numbers in fish oil is pro analysis grade ethanol.

The cosmetics industry in Indonesia has experienced a significant increase of 12.6% from 2022 to June 2023, with 1025 industries having a positive impact on the Indonesian economy. Apart from that, it has triggered a number of naughty manufacturers to use dangerous chemicals in their cosmetic products such as mercury (Hg). Therefore, it is important to develop a fast and sensitive method for detecting mercury in cosmetics using SPCE-AuNPs. This research was carried out by synthesizing gold nanoparticles (AuNPs) using the reducing agent sodium citrate (Na3H5C6O7) with varying concentrations and characterization of several chemical instruments. Furthermore, SPCE was modified by AuNPs, its performance and application were tested to detect mercury in cosmetic cream using cyclic voltammetry (CV). SPCE-AuNPs provides an electrochemical response with higher oxidation and reduction peaks than bare SPCE with an oxidation peak at a potential of 0.1 V to 0.3 V and a reduction peak at -0.05 V to 0.05 V at a scan rate of 0.01 V/s to 0.03 V/s. This shows a good electrochemical response so it can be used for application to detection of mercury in cosmetic samples. The SPCE modified using AuNPs can potentially be used as a sensor for mercury detection in cosmetics.

Tamarindus indica is commonly used interest in Sudan for edible plant and medicinal use. This study aimed to determine bioactive compounds, and antioxidant activities in extracts and fractions of Tamarindus indica pulp grown in Sudan. The powdered plant was extracted with ethanol, ethyl acetate, and acetone using an ultrasonic technique. The residue of the ethanol extract was fractionated using successive solvents. The extracts and fractions were determined for their phenolics, flavonoids, and tannins contents, and analyzed bioactive compounds by Gas Chromatography-Mass Spectrophotometer, and also evaluate their antioxidant activities using the 2, 2-diphenyl-1-picryl-hydrazyl, reducing power and hydrogen peroxide scavenging methods. The results show that the total phenolics, total flavonoids, and total tannins levels were significantly higher in the ethyl acetate fraction than in other extracts and fractions. GC-MS analyses of extracts and fractions showed a variety of bioactive compounds such as Hexadecanoic acid, Stigmasterol, Maltol, Sitosterol, Vitamin E, Allose, Tartaric acid, and Vaccenic acid. All the extracts and fractions exhibited good antioxidant activities. The extracts and fractions of Tamarindus indica pulp are sources of natural antioxidants and other bioactive compounds, which are beneficial effects on human health and the possibility of application in the pharmaceutical industry.

Metabolomics has emerged as a critical field in understanding biological processes and disease mechanisms, necessitating advancements in analytical techniques to handle complex biological samples. This review explores the global landscape of metabolomics, with a focus on the use of spectroscopy and spectrometry. Techniques such as UV-Vis and Fourier Transform InfraRed (FTIR) spectroscopy offer fast and cost-effective metabolite tracing but are limited by their sensitivity, particularly for low-abundance metabolites. Nuclear Magnetic Resonance (NMR) spectroscopy, despite being less sensitive than mass spectrometry (MS), provides unparalleled structural information, distinguishing metabolites with similar mass-to-charge ratios. NMR's capability to detect metabolites in the 1-10 µM range highlights its effectiveness in metabolomics. This review categorizes advancements in these techniques, starting with global contributions to spectroscopy, followed by detailed discussions on FTIR strategies for metabolite tracing, and concluding with NMR's qualitative and quantitative applications in metabolomics and disease diagnostics. The review underscores the continuous development in sample preparation and data integration, enhancing the accuracy and applicability of these techniques, positioning NMR and FTIR as essential tools in modern metabolomic research.

This research focuses on optimizing patchouli oil yield using the hydrodistillation method and adding MgCl2 as the main component. The RSM method is used to analyze model variance, including the sum of squares model, less of the fit model, and ANOVA analysis. The research results show that adding MgCl2 can increase the yield of patchouli oil by reducing water content and undesirable non-volatile elements, thereby producing more stable patchouli oil. ANOVA analysis of patchouli oil yield was carried out to determine the optimal results from factors such as F/S, material size, and time. The extraction time factor had a p-value of less than 0.05, indicating that the model was suitable for explaining the results. The research results showed that the yield of patchouli oil was optimal with an F/S ratio of 0.075, material size of 20 mesh, and extraction time of 5 hours, with a yield of 0.1 gr/mL being the best choice. The research results showed that the use of specific methods, namely distilled water and MgCl2 in the extraction process, was effective in increasing the yield of patchouli oil

This study aimed to investigate the chemical structure, thermal properties, and stability of polylactic acid (PLA) composites blended with multi-walled carbon nanotubes (MWCNTs) and polyethylene glycol (PEG). The composites were fabricated using a masterbatch blending method with two different molecular weights (Mw) of PEG. The masterbatch was initially prepared using solvent casting with chloroform as the solvent, followed by melt blending using an extruder. ATR-FTIR spectroscopy identified strong hydrogen bonds between the C=O groups of PLA and the –OH groups of PEG, as evidenced by the peak at 1748 cm¹. Differential Scanning Calorimetry (DSC) revealed that incorporating 14 wt% of PEG 10,000 into PLA/MWCNT composite significantly enhances the melting enthalpy (∆Hm) from 18.3 J/g to 24.6 J/g and the degree of crystallinity from 2% to 17.3%. The glass transition temperature (Tg) decreased with the addition of PEG, indicating increased chain mobility, while the melting temperature (Tm) remained relatively constant around 158 oC regardless of the PEG Mw. Despite the plasticizing effect of PEG, the thermal stability of the composites was maintained across different PEG Mw. Scanning Electron Microscope (SEM) images showed that MWCNTs were well dispersed within the blend, facilitated by ultrasonic stirring during preparation.

Environmental pollution is increasingly becoming a major global problem. Surface water pollution impacts human life and the ecosystem, emphasizing the need for water quality assessment and monitoring. In this study, water Samples were collected in Ogun River for two years (twice a year) and analyzed for the physicochemical parameters using standard methods. The results show that there was spatial and seasonal variation in the water quality of the river. The physical parameters Turbidity, EC, and TDS had significant positive correlations with each other but correlated negatively with DO and pH. A significant positive correlation also existed between pH and DO (0.918). Cluster analysis grouped the parameters into three clusters, while the PCA yielded 2-components, which explained 85.61 % of the total variance in the data set. Component 1 accounts for 69.26 % of the total variance and has strong positive loadings for Turbidity, EC, and TDS and strong negative loadings for pH and DO. Component 2 accounts for 16.35 % of the total variance, with strong positive loading for BOD. The results indicate that factors that increase the Turbidity, EC, and TDS levels will decrease the levels of pH and DO while exerting a less significant effect on BOD. This study provides valuable insight into the changes and interactions of parameters that affect the water quality, which is crucial for the sustainability and quality management of the water system.

A literature review of the available spectrophotometric methods of determination of catecholamines is presented. Based on this review, two simple spectrophotometric methods for the determination of norepinephrine bitartrate in pharmaceutical formulations and industrial equipment cleaning rinse waters were chosen and validated. The first method for the determination of norepinephrine at ppm levels utilizes the absorbance band of the solution of norepinephrine bitartrate at 279 nm. The second method for the determination of norepinephrine at ppb levels is based on the reaction of norepinephrine with the Tollens’ reagent in the presence of the cationic surfactant cetylpyridinium chloride and the colorimetric determination of the formed colloidal silver nanoparticles. The calibration graphs are linear in the range from 1 to 150 mg/l of norepinephrine for the first method and 25 µg/l to 10 mg/l for the second method. The molar attenuation coefficients are 388 and 7560 m2/mol, respectively, the limits of detection are 1.1 mg/l and 3.1 µg/l, and the limits of quantification are 3.3 mg/l and 9.4 µg/l, respectively. Both methods are selective concerning the common excipients, show good accuracy (the relative uncertainties do not exceed 4 and 7%, respectively) and precision (the relative standard deviations do not exceed 4 and 7%, respectively), and do not require lengthy sample preparation and sophisticated laboratory equipment.

The ethyl acetate extract of fungus comb was investigated for its potential as an α-glucosidase enzyme inhibition agent. The extract was evaluated using bioassay methods to determine its IC50 values against enzyme activity, alongside phytochemical screening to identify active compounds. The optimal concentration of α-glucosidase enzyme was determined to be 0.06 U/mL. Results indicated that the extract and its fractions exhibited α-glucosidase enzyme inhibition activity, albeit with IC50 values higher than the positive control, acarbose. Fractions containing phenol-hydroquinone showed the most vigorous activity, while fractions containing saponins displayed varied activities, possibly due to contaminants interfering with enzyme interactions. This study highlights the potential of the fungus comb extract as a promising source for developing antidiabetic agents.

This review provides a state-of-the-art summary of the role which zeolite plays as a catalyst via pyrolysis as a way of recovering fuels and chemicals from waste high and or low density polyethylene bags. It also highlighted the two types of zeolite (natural or synthetic) which are used as a two-stage pyrolysis−catalysis in giving a free waxing product to pure fuel and chemicals which can be subjected to further analyzing and or upgrading. As yield of oil/wax decreased with the addition of a zeolite as catalyst from 44 and 51 wt.%, (depending on the waste high density polyethylene “HDPE” or low density polyethylene bags “LDPE” and other factors). However, the composition of the pyrolysis−catalysis oils significantly increased in aromatic hydrocarbon content accordingly. In addition, the composition of the oils shifted from high molecular weight hydrocarbons (C16+) to fuel range hydrocarbons (C5−C15), with a high content of single-ring aromatic hydrocarbons such as benzene, toluene, ethylbenzene, xylenes, and styrene. This process shows great potential for production of fuels or chemicals, and also addresses the urgent issue of waste HDPE and or LDPE disposal.

Solanum ferox is a typical Central Kalimantan plant widely used by Dayak’s community as a vegetable. The study aims to determine the ethanol extract of sour eggplant activities by measuring its SPF in vitro and identifying secondary metabolite contents. The sour eggplant is extracted by maceration using 96% ethanol solvent and then bound with an evaporator. The secondary metabolite groups of ethanol extract were identified using phytochemical screening. The identification results indicate the presence of flavonoid, terpenoid, steroid, and phenolic compounds. Then, the ethanol extract was fractionated with a water solvent, and its functional cluster was identified using the IR spectrum. IR spectral identification results indicate the presence of OH, C-O, C=C olefin, C -O ether, and aliphatic CH functional groups. (CH2 and CH3) SPF values were determined by measuring the absorption of ethanol and water extracts in vitro using UV-Vis spectrophotometry at UV-B wavelengths of 290-320 nm. In vitro testing has been conducted as a preliminary test in developing a sunscreen product (active substance). The SPF values of ethanol extract and water from weighted fruit extract in sequence are 40 and 23 at a 10% concentration with ultra-category.

Validation of the method for determining ethanol in vinegar and beverages has been carried out in the linearity range of 0.05-1% using GC-FID. This research was carried out using an internal standard solution and without an internal standard solution. The research aims to validate the linearity of ethanol determination at low concentration levels. This validation is useful to ensure that the ethanol test method in the sample can be detected at low concentration levels. In the halal authentication process, the maximum limit for ethanol content is 5%. The method validation results confirm that in the concentration range 0.05-1% it has good linearity with a correlation coefficient (R) without the addition of internal standards and with the addition of standard solutions being 0.9972 (R2=0.9943) and 0.9952 (R2=0.9905). The results of the analysis of variance (ANOVA) test with a 95% confidence interval and 9 degrees of freedom F-count (0.0141) < F-critical (0.3146) show that the range 0.05-1% corresponds to the limit of linearity. The results of the ANOVA test with a 95% confidence interval with df=6 show the F-test value (0.0879) < F-critical (0.2334) indicating that the two proposed methods have high precision and no significant differences. Both methods also have high accuracy and no significant differences in accuracy as shown by the results of the ANOVA test with a 95% confidence interval and degrees of freedom = 6 showing the F-test value (1.5204) < F-critical (4.2839). It is recommended that the results of this validation be useful in the halal verification process for vinegar and beverage products.

Turmeric powder (Curcuma longa L.) is often used for food coloring and flavoring. The high demand for turmeric powder has led to adulteration, one of which is metanil yellow. This study aims to detect metanil yellow dye in turmeric powder using Infrared Spectroscopy (FT-IR) and Chemometrics. The chemometrics model was built by preparing turmeric powder and metanil yellow in the concentration range of 0-50% (w/w). Data was processed using multivariate calibration using OPLS-DA (Orthogonal Partial Least Squares Discriminant Analysis) and PLS (Partial Last Square). The results obtained from OPLS-DA processing of market samples 1 and 2 are estimated to be pure turmeric powder, and samples 3 to 10 are adulterated. From the PLS results, the best calibration model was obtained at wave numbers 1199-539 cm-1 with R2 values for calibration and validation of 0.9967 and 0.9970, respectively, with RMSEC of 2.48 and RMSEP of 6.35. The PLS results showed that in sample 3 containing metanil yellow, in samples 4 to 10, no metanil yellow was detected. The ingredients added were not metanil yellow. It was concluded that FTIR combined with chemometrics could detect the metanil yellow in turmeric powder.

The carcinogenic and teratogenic properties of mercury have driven the necessity for the development of highly sensitive methods capable of detecting even trace amounts of the element. In response to this need, an analysis technique has been established for mercury ions, employing preconcentration methods utilizing filter paper modified by silver nanoparticles (AgNPs) and 3-Amino propyl trimethoxy silane (APTMS). This method allows for the detection of mercury ions through the voltammetry technique, ensuring accurate and reliable results. Upon conducting analyses using this method, it was found that the tested cosmetic samples were free from Hg2+ ions, indicating the absence of mercury contamination in the cosmetics under investigation. The correlation coefficient derived from the graph of the analysis results stands at an impressive value of 0.9976, affirming the strong relationship between the measured concentrations and the actual mercury content. Additionally, the method demonstrates excellent sensitivity, as evidenced by the low limit of detection (LOD) value of 0.0483 mM and the limit of quantification (LOQ) value of 0.1611 mM.

Heavy metals Cd2+ is a dangerous pollutant of water and ecological systems if it is above the quality standard threshold. Cassava peel has a fairly high carbon element content, namely 59,31%, so it can be used as an activated carbon to break down Cd2+ metals ions in water. This research aims to determine kinetic modeling and adsorption isotherms of Cd2+ ions using CPAC activated by H3PO4, determine the optimum pH and temperature conditions for Cd2+ ion adsorption and determine the adsorption capacity of Cd2+ ions using CPAC activated by H3PO4. CPAC is made through a carbonization process at a temperature of 500 °C for 1 hour. Next, it was impregnated with H3PO4 at a concentration of 30 % with a ratio of 1:5 (w/w) for 24 hours and physically activated at a temperature of 600 °C for 1 hour. Based on research, kinetic modeling and adsorption isotherms of Cd2+ ions using CPAC activated by H3PO4 following Pseudo-Second-Order (PSO) kinetic modeling and Freundlich isotherm, the optimum pH and temperature conditions for Cd2+ ion adsorption were obtained at pH 5 and temperature 25 °C. Thermodynamic parameters such as Gibbs energy (∆G°), enthalpy (∆H°), and entropy (∆S°), have been evaluated and indicate physical, spontaneou, and exothermic adsorption processes. The adsorption capacity of Cd2+ ions using CPAC activated by H3PO4 is 5.2219 mg/g.

Mojokerto City, located in East Java, grapples with a steadily rising waste generation trend accentuated by the COVID-19 pandemic. Drawing data from the National Waste Management Information System (SIPSN) and supplemented with an exhaustive literature review, this study scrutinizes the potential of biodigester technology as a solution to this mounting challenge. Mojokerto's waste, consistent in its composition from 2019 to 2022, is dominated by food waste, making it an ideal candidate for biodigester intervention. The study revealed that existing biodigester facilities in Mojokerto vary in their waste reduction efficiencies yet collectively demonstrate the viability of converting food waste to energy. For instance, the TPS 3R Magersari Berseri facility showcased an impressive waste reduction rate of 85.0%, processing 62.05 tons out of 73 tons of waste received annually. Comparative analyses of other facilities like TPS 3R Pulorejo "Cahaya Berseri" and TPS 3R Muria Berseri were also conducted, revealing varying degrees of efficiency. These facilities underscore the potential of biodigester technology in managing the rising tide of waste and contributing to sustainable energy generation. The findings of this study also call for increased awareness about food conservation, improved waste segregation at the source, and the promotion of composting and other organic waste processing methods, thereby optimizing the overall efficiency of waste management in the city. .

Identification of acetic acid-ethanol mixtures using a commercial gas sensor array equipped with ensemble regression has been carried out. The gas sensor analysis was simple, rapid, and fast since it did not require any sample preparation. A quantitative analysis of the acetic acid-ethanol mixture was carried out to determine the sensitivity and selectivity of the sensor in distinguishing the concentration of the acetic acid and ethanol mixture. This study focuses on the coefficient of determination of 80% of the calibration data set and recovery of 20% of the testing data set. The models showed excellent performance,specifically, the Bagging and Random Forest r2 for the ethanol calibration data reached 0.91 and 0.94, respectively. The corresponding ethanol test recoveries were 99.95% and 97.84%, indicating the robustness of the model in accurately predicting ethanol concentration. Acetic acid test recoveries were 100.56% and 101.38% with r2 of 0.89 and 0.93 for Bagging and Random Forest regression, respectively. Hence, the commercial gas sensor array equipped with ensemble regression can be applied to the quantification of the acetic acid – ethanol mixture and demonstrate opportunities for the practical use of this gas sensor array in analyzing real samples, i.e. human breath or environmental monitoring samples.

Can Gio, designated in 2000, is the first Biosphere Reserve of Vietnam. In recent years, local agriculture, tourism, households, nearby industrial zones, and maritime transport have released substances into rivers flowing through Can Gio Mangrove to the East Sea and transported into creatures. This study aims to investigate microplastics and heavy metals in the famous seafood of Can Gio. A Raman microscope was used to identify microplastics from the tissue of oysters, grease snails, and clams after enzymatic treatment with trypsin. Heavy metals were quantified with ICP-MS after acidic treatment. As a result, microplastics were found in almost all samples, even up to 10 in a random individual of bivalve. Fibers dominated, especially from 30 to 150 µm long. The metal with the highest content was zinc, followed by copper, especially in oysters. Non-essential metals were also present in the soft tissue in the order As > Pb > Cd. The accumulation of metals in Can Gio’s molluscs was generally lower than in other regions and still in the allowed range for consumption of Vietnamese Standard. Although there have not been any Vietnamese regulations on the permissible level of microplastics for consumption, regular seafood intake will increase the risk of chronic poisoning and unknown disorders caused by the accumulation of microplastics and heavy metals.

In this study, the adsorption of Remazol Blue and Indigosol Yellow using Bidara Arab leaves (Ziziphus spina-christi) as adsorbents was investigated through batch adsorption. The experimental parameters included contact time, adsorbent mass, initial concentrations, and pH. UV-Vis spectrophotometer was employed to measure the adsorption results at the maximum wavelength of each dye. The research was conducted in triplicate, and a t-test, "Paired Two Sample for Means", with a standard deviation

Identification of compounds and acetone extract activity from P. crocatum red shrimp has been done using phytochemical testing and Brine Shrimp Lethality Test (BSLT). The extraction begins with maseration using an acetone solvent and then the solvent is moved using an evaporator. Identification of extract function groups using the IR and GC-MS spectrum, as well as the toxicity test of the extract was carried out against the 48-hour Artemia salina Leach shrimp larva. The identification results showed the presence of flavonoids, phenylpropanoids, and steroids supported by GC-MS data and IR spectrum that indicated the existence of OH groups, C=O esters, C=O ketones, C=C olephins, C=C aromatic, C-O ester, and aliphatic CH. The results of probit analysis (LC50) showed that the acetone extract was highly toxic (LC50 0-100 μg/mL) to Artemia salina Leach with LC50 value of 2.4520 ppm.

Halal food safety issues receive serious attention. Methods for analyzing contamination of non-halal ingredients, such as lard, must be developed to assist in the halal authentication process for food. This study was conducted to compare the fat profile of pork thighs using FT-IR and GC-MS. The pork is dried in the oven and then extracted using n-hexane. The resulting fat was characterized by FT-IR. Determination of fatty acids was carried out by GC-MS using a derivatization technique. Based on the results of the study showed that the infrared pattern of lard can be identified from the difference in absorption intensity. Pork fat has a higher unsaturated fatty acid content than beef and chicken. Infrared spectra can confirm the presence of -C=C- bonds at 3005, 1745, 1116, 1550, and 722 cm-1. The FTIR data shows that there are larger unsaturated fatty acid groups in pork fat than in beef and chicken fat. This procedure is a non-destructive method that can be carried out quickly, and cheaply, and can be developed into a routine procedure for halal authentication of food. Based on the results of unsaturated fatty acid testing with GC-MS it can show the content of oleic acid (C18:1) contained in pork. The results of mapping the content of free fatty acids in pork can be used to complete halal authentication data easily and quickly.

The Company's input pipes contained microplastics, per the preliminary test findings. While the water yield produced by PDAM Tirta Daroy contains 150 particles/L, the Tirta Daroy Drinking Water Area has 275 particles/L. Microplastics found in the water pose a major risk to living beings if they are consumed. This work aims to characterize the properties, flux, and polyethersulfone (PES) membrane rejection coefficient, which were made utilizing the phase inversion technique with a solvent and additives called N,N-dimethylformamide (DMF). In Sungai Krueng Aceh, titanium dioxide (TiO2) is utilized to filter out microplastics from the water. Results of Scanning Electron Microscopy (SEM) examination of Membrane Morphology demonstrate that the resulting membrane is an asymmetrical membrane of two layers, the upper layer relatively thin and the lower layer porous. When compared to the PES membrane when it was 15% DMF/TiO2, the 20% DMF/TiO2 membrane exhibits a finger-like cross-sectional structure called a macrovoid) with more and larger numbers. Analysis of the microplastic rejection coefficients proved the effectiveness of PES, DMF, and TiO2 membranes in removing microplastics. Results of tests on the effectiveness of rejecting microplastics after undergoing process filtration with a microplastic rejection coefficient of 94% and 14.2 particles/L utilizing a 20% PES/DMF/TiO2 membrane Performance of PES membranes: The PES membrane with 20% DMF/TiO2 has a water flux of 0.467 L/m2.hour compared to 15% DMF/TiO2 0.733 L/m2.hour. This study's findings on membrane Ultrafiltration have the potential to be used as a water filter standard in PDAM.

Exploration of soursop leaf extract (Annona muricata L.) as one of the natural inhibitors against the corrosion process. The objective of this research is to determine the effect of the extract on inhibiting the corrosion rate of steel. The corrosion rate is determined by the decrease in the mass of the steel during immersion in various concentrations of sulfuric acid solutions, namely 0.01, 0.05, and 0.1 M, and optical microscopy will be used to analyze the corroded steel samples. This study consists of several stages: soursop leaf extraction, steel sample preparation, inhibitor solution and corrosive media preparation, immersion, and characterization. The extraction method is performed by maceration for 168 hours to obtain the extract. The highest corrosion inhibition efficiency obtained is 63.1% with the presence of 600 ppm inhibitor in 0.01 M sulfuric acid solution, while the lowest corrosion inhibition efficiency obtained is 14.8% with the use of 200 ppm inhibitor in 0.1 M sulfuric acid solution. The types of corrosion that occur on the steel surface are uniform corrosion and pitting corrosion.

Utilizing personal protective equipment (PPE) is the important requirement for controlling and preventing of Covid-19 virus spread. The awareness of mask-wearing among the citizen and the development of fabric mask testing methods based on Indonesian Standards through the implementation of SNI 7648: Textile – Test of the air permeability on fabric; SNI 20743: The evaluating method of antibacterial properties using biological aerosol S. aureus and E. coli; SNI/ISO 4920: The surface wetness testing. This study shows that we need to understand and choose fabric masks correctlybesides being standardized. Fabric types influence the performance of the mask while protecting the user.

Bamboo-based activated carbon (BAC) has been successfully synthesized through a physico-chemical technique. The characteristics of BAC were investigated using Scanning Electron Microscopy (SEM), Fourier Transform Infra-Red (FTIR), and X-Ray Diffraction (XRD). Evaluating BAC performance on coal-runoff wastewater was carried out by varying contact times and adding low-level alum on remediation of pH and Total Suspended Solid (TSS). The results confirm that BAC performs well in stabilizing pH, indicated by the neutral pH, after 10 minutes of interaction. The TSS with BAC treatment and 1% BAC-Alum combination reduced the TSS value from 880 mg/L to levels below the threshold for wastewater quality standards, 387 mg/L and 73 mg/L, respectively. This combination can be an alternative coal-runoff wastewater treatment technique for better environmental quality.

Areca nut or Areca catechu L is a plant that has many benefits, one of which is that it can be used as medicine. There are secondary metabolite compounds in betel nut. The presence of this secondary metabolite content makes the betel nut skin a high potential as a bioreductant to synthesize silver nanoparticles as an antibacterial. The process of synthesizing silver nanoparticles is carried out with the addition of a stabilizer in the form of Polyvinyl alcohol (PVA). The analysis results obtained using the UV-Vis instrument have wavelengths with variations in the addition of 1%, 3% and 5% PVA, respectively, are 448 nm, 456 nm and 460 nm. In the results of the analysis using XRD, the value of 2θ is silver nanoparticles (PVA 1%): 38,020; 43,930 ; 64,320 ; 77,270. silver nanoparticles (PVA 3%): 38,230; 44,270 ; 64,610 ; 77,500. And silver nanoparticles (PVA 5%) are 38,100 ; 44,240 ; 64,460 ; 77,370. For analysis using SEM, the particle size obtained with the help of the Imegej and OriginLab 8.5 applications, namely at AgNPS + PVA 1% is 28 nm - 31 nm. Agnps + PVA 3% ranged from 26 nm – 29 nm. And Agnps + PVA 5% has a size of 19 nm – 22 nm. For the results of FTIR data, the specific absorption peaks of Ag nanoparticles are located at frequencies of 412.23 cm-1, 453.57 cm-1, and 476.84 cm-1. Then in the antibacterial test, silver nanoparticles were used with the addition of 5% PVA. The size of the clear zone obtained in the test for E. coli bacteria is 11.2 mm and for S. Aureus it is 13 mm

Silver nanoparticles (AgNPs) have several applications in nanoscience and nanomedicine such as antibacterial, antifungal, anti-inflammatory and anti-angiogenic properties. In the present study, the AgNPs were synthesized by the chemical method and characterised using a combination of UV-Visible (UV-Vis) spectrophotometry, Fourier Transform Infra-Red (FTIR) spectroscopy, transmission electron microscopy (TEM) and X-ray diffraction (XRD). The AgNPs were made by chemically reducing AgNO3 with NaBH4 leading to the formation of a characteristic yellowish-brown colour of AgNPs. To investigate the formation, crystalline behavior, and quality of AgNPs powder, XRD measurements were performed. The produced AgNPs were found to be spherical, dispersed, and scattered in form and the particle size of the AgNPs formed was about 15 nm and they were crystalline in nature. The interaction of AgNO3 with biomolecules may have numerous applications in nanoscience and nanomedicine.

Lignocellulose compounds contained in water hyacinth leaves (WHL) (Eichhornia crassipes) can be used as raw material for the manufacture of activated carbon at a low and renewable rate. The ACWHL can be used as adsorbent for reducing a COD value and turbidity levels on laundry waste. The purpose of this study is to determine the best adsorption modelling of ACWHL on COD values and turbidity levels in laundry waste in kinetics and isotherm studies and determine the effectiveness of reducing a COD value and turbidity levels. The process of making ACWHL is carried out by carbonization at 400 °C for 1 hour, then activated using 30% H3PO4 at an impregnation ratio of 1:4 (w/w) for 24 hours and physical activation at 600 °C for 1 hour. The results showed that the adsorption of ACWHL on COD value and turbidity levels of laundry waste followed Freundlich isotherm and Elovich isotherm modelling with R2 values of 0.9535 and 0.9905, respectively. The modelling for adsorption kinetics of COD values and turbidity levels in laundry waste follows the Pseudo Second Order kinetics modelling. The effectiveness of ACWHL reduction in adsorption of COD value and turbidity levels of laundry waste was 80.76% and 64.71%.

This study presents a direct multicomponent analysis method using UV-Vis spectrophotometry to determine Cu(II), Fe(III), and Ni(II) ion content without prior complexation or separation. Single and multivariate regression was used to predict metal ion content, and the resulting model was trained and validated using a dataset of 25 multi-component samples. The mean recoveries for Cu(II), Fe(III), and Ni(II) using linear and ridge regression based only on absorbance at 805 nm were 99.97% and 101.6%, 95.42% and 95.65%, and 99.43% and 99.99%, respectively, for the 20% test data. The mean recoveries for Cu(II), Fe(III), and Ni(II) using linear and ridge regression based only on absorbance at 805 nm were 92.27% and 95.03%, 125.3% and 124.11%, and 104.15% and 105.52%, respectively, for the test solution outside of the training data. These results demonstrate the effectiveness of the multivariate UV-Vis spectrophotometric method for the simultaneous determination of Cu(II) and Ni(II) in multicomponent samples, which meets the analysis standard and can be successfully applied. Finally, the study sheds light on the influence of spectral interference on the accuracy of regression models. It highlights the importance of carefully selecting the wavelengths used as predictors in such models. This can have significant implications for developing and validating analytical methods, particularly in cases where multiple analytes were present in a sample.

The use of palm oil mill fly ash (FA) as a low-cost adsorbent is one of the solutions for handling FA waste. In this study, the addition of dolomite is expected to improve the adsorbent performance. The aim of this study was to investigate the optimum FA-dolomite adsorbent composition and operating conditions for methylene blue adsorption. Different parameters were studied to optimize adsorption process such as the amount of dolomite, methylene blue flow rate, bed height and number of trays. FA-dolomite was converted into nano-adsorbent by sol-gel method which was coated on zeolite surface. Nano-adsorbents were characterized by XRF, FTIR, XRD and SEM. The adsorption capacity was tested by Spectrophotometer UV-Vis. XRF characterization showed that FA had the highest SiO2 content of 58.15%, while dolomite contained CaO of 52.72%. FTIR characterization detected the groups of Si-O-Si, Si-O-Al, Ca-O and Si-O. XRD characterization showed the average crystalline size of FA-dolomite 2% adsorbent was 28.56 nm and SEM characterization showed fine pores on the adsorbent surface. The highest adsorption efficiency obtained at FA-dolomite 2% was 97.364% and the lowest obtained at FA-dolomite 8% was 13.16% with a flow rate of 500 ml/h, adsorbent height of 9 cm and 3 trays. The greater the amount of dolomite added, the absorption efficiency decreases.

This work presents the successfully of TiO2 nanostructure synthesis using manual grinding combined hydrothermal method for photocatalyst. XRD confirmed that TiO2 was arranged by anatase and rutile phase with crystal size of 18.54 nm. Characterization of digital microscope shows the spread of catalyst on the glass tube surface, which can be observed furthermore using interactive 3D surface plot. Band gap energy determination from UV-Vis spectroscopy scanning shows the minimum energy that is required to facilitate electron-hole generated. In 20 min of irradiation, TiO2 existence can completely decompose MB (100%) that can be presented by TiO2 absence. Degradation of MB is higher effective in acidic condition which optimum pH of 5. Using first order reaction, glass tube-coated TiO2 has rate constant of 0.2102 min-1, 1.5 times faster than bare glass tube. This enhancement proves that the designed reactor has good prospect for organic pollutant treatment. Moreover, compared with other reported study, this system provides relatively more effective of MB photodegradation.

Polymer additive’s function is to improve film quality, including slip additives which function as film surface lubricants. Slip additives affect the physical characteristics of the film as indicated by the coefficient of friction and optical properties. In this research, the influence of slip additives and the aging time of the coefficient of friction (COF) and the optical properties of polyethylene (PE) films have been studied. The optical properties of the film are measured based on the haze value and the gloss value. The additives used in this study were erucamide, stearyl erucamide, and a mixture of the two. Observations were made for 14 days at 23 °C and 50 °C. Measurements of the COF, haze value, and gloss value were carried out on days 0, 1, 3, 7, 10, and 14. The results showed that the lowest COF was produced on films with erucamide additives. Films with erucamide additives had the best friction coefficient value of 0.129 on the 3rd day of aging at 50 °C, a haze value of 4.63% and a gloss value of 56.5 GU.

Kaolin with alumina and silica content is used as the main material in this research to study the synthesis of ZSM-5 zeolite. The hydrothermal process was carried out through different aging times, namely 12, 24 and 36 hours. Tetrapropyl ammonium bromide (TPABr) was used as a template for the Mobile Five-1 (MFI) structure guide. X-ray diffraction (XRD) and infrared spectroscopy (FTIR) instruments were used to characterize the ZSM-5 zeolite formed from the synthesis results. This was done to identify the phase change from kaolin to zeolite ZSM-5. The results of the analysis using XRD for all samples showed a characteristic peak of the ZSM-5 zeolite at 2θ around 7.88°; 8.72° ;23.09°; 23.84° and 24.32°. However, samples with an aging time of 12 hours also showed peaks at 2θ around 15.84° and 26.03° which indicated an analsim phase. The absorption bands from the FTIR characterization for all samples are seen at wave numbers around 453, 542, 793, 1088 and 1221 cm−1 which are the characteristic peak points of ZSM-5 zeolite. The longer the aging time indicates that the crystallinity of the ZSM-5 zeolite is increasing. The highest crystallinity was obtained from ZSM-5 zeolite samples which were aged for 36 hours. This indicates an increasing number of ZSM-5 crystal nuclei with high purity because there is no other phase besides the ZSM-5 phase.

Thin film of TiO2 modified Ni2+ cationic (Ni doped-TiO2) thin films were synthesized from titanium tetraisopropoxide (TTIP) and Ni(NO3)2.6H2O using the combined sol-gel and dip coating method followed by calcination at 500oC for an hour. This study aims to determine the concentration of Ni2+ and the optimum number of layers for application as self-cleaning. Frontier transform infrared (FTIR) spectrophotometric analysis observed a shift in the vibration absorption peak of Ti-O towards a smaller wave number as an indication that the Ni2+ cationic have incorporated in the TiO2matrix in forming Ni-TiO2. Based on the of x-ray diffraction (XRD) it is known that Ni-TiO2 has anatase crystalline phase with a crystallite size of 149.20 nm. Diffuse reflectance ultraviolet-visible (DRSUV-Vis) spectrophotometry showed a decrease in the bandgap energy (3.2 eV to 2.22 eV). Surface morphological by scanning electron microscopy (SEM) method showed that the addition of polyethylene glycol (PEG) resulted in a more homogeneous distribution of particles than thin films without PEG. The self-cleaning activity of Ni-TiO2 was tested for surface hydrophilic properties by measuring the contact angle of water and oil droplets under visible light illumination.

Biofoam can be used as an alternative packaging to Styrofoam. Biofoam made from starch and cellulose fibers has biodegradable properties. In this study used pineapple leaf fiber as an additive to strenghen on mechanical properties of biofoam. The research method consists of several stages, cooking pineapple leaf fiber, biofoam preparation, and testing phase on the resulting biofoam. The mechanical characteristics test of biofoam is a tensile strength test of 1.66-2.86 Mpa. Compound composition test through Fourier Transform Infrared Spectroscopy (FTIR) is hydrophilic which binds to water so that it is easily degraded by soil, thermal characteristics with DSC thermogram test of pineapple leaf fiber biofoam sample 15 gr shows at a temperature of 98.04 °C occurs peak thermogram showing physical changes. TGA analysis showed that biofoam has good thermal stability. In the morphology of biofoam visible white lumps and grooves on the surface that shows the solubility is not too perfect due to the influence of stirring time.

Agricultural waste with a high starch content potentially serves as a source of resistant starch. The avocado seed has not been explored much and is often thrown away as waste in consuming avocados. Resistant starch has properties and functions as dietary fiber and has advantages as a prebiotic. This study aims to determine the effect of fermentation treatment using Streptomyces sp. AB 8 and variations in the number of pressure-cooling heating cycles to increase avocado seed-resistant starch. The research phase consisted of pre-treating the avocado seeds and fermentation by Streptomyces sp. AB 8 followed by a pressure heating-cooling stage with 0, 1, 2, and 3 cycles. Concerning modified starch, this study also measured levels of starch, amylose, amylopectin, and resistant starch. Digestion test using Lactobacillus sp. by viewing the clear zone around the colonies after 48 hours to evaluate the digestibility of resistant starch. The results of this study indicate that the fermentation treatment by Streptomyces sp. AB 8 and pressure-cooling heating can increase the levels of resistant starch in avocado seeds. Fermentation treatment with two cycles of heating-pressure-cooling (S1) produced the best resistant starch content of 7.51% and had the highest enzymatic index of 2.48 ± 0.45.

Kebun Raya Liwa’s soil has the potential to allow for a population of microorganisms such as the Bacillus sp. Bacillus sp. Kebun Raya Liwa are known to produce phytohormones that have the potential to help plant growth and development, one of which is the hormone Indole Acetic Acid (IAA). This study aims to determine the potential of Bacillus sp. from the soil of Kebun Rawa Liwa in producing IAA hormones. The research method included taking soil samples, preparing Nutrient Agar (NA) medium, measuring soil pH samples, isolating soil bacteria, purifying and characterizing Bacillus sp., preparing IAA standard curves, and testing the potency of Bacillus sp. IAA production was carried out in two ways, namely measuring the content of IAA with the addition of tryptophan and without the addition of tryptophan. IAA concentration was measured using a spectrophotometer with a wavelength of 520 nm. The data obtained is presented in tabular form. The isolation results obtained 10 isolates that were able to produce IAA hormone with and without tryptophan. The highest IAA production without tryptophan was isolate BP 5 with a concentration of 1.18 ppm, and the isolate that was able to produce the highest IAA with tryptophan was isolate BP 13 with a concentration of 3.90 ppm. This indicates that the isolate Bacillus sp. from the soil rhizosphere Kebun Raya Liwa can produce IAA hormones.

One of the things that causes cell damage in the body is the formation of unpaired electrons, also known as free radicals, which can cause oxidative stress. Excessive oxidative stress is not maintained by the body's natural antioxidants, so natural antioxidants are needed from outside. One of the plants suspected of having antioxidant abilities is Pakis kinca. So, the aim of this study was to determine the levels of flavonoids and antioxidant abilities in the tuber of N. cordifoli. Therefore, the method used to determine flavonoids is by reacting with AlCl3 and reading by UV-vis spectrophotometry, while reacting antioxidants with DPPH using spectrophotometry. The results of the flavonoid test were 3.119 ± 0.09 w/w equivalent to quercetin, from this equation the flavonoid content in the range of the equation was obtained. The results of the antioxidant test obtained the mean value of antioxidants was 93.898 ± 0.923. The conclusion obtained is that the antioxidant IC50 value of tuber extract N. cordifolia is a strong category with a total flavonoid content of 3.119 ± 0.091 w/w equivalent to quercetin.

Kesadaran konsumen terhadap makanan berkualitas dan ramah lingkungan semakin tinggi. Beberapa penelitian telah mengembangkan produk pengemas yang edible dan aktif. Penelitian ini bertujuan untuk menghasilkan edible film yang memiliki aktivitas antibakteri. Pembuatan edible film pada penelitian ini menggunakan bahan dasar pati yang diekstrak dari ubi kayu. Bahan tambahan yang digunakan yaitu Carboxymethyl cellulose, gliserol dan minyak cengkeh. Variasi konsentrasi minyak cengkeh yang digunakan yaitu 1%, 2% dan 3%. Berdasarkan analisis Gas Chromatography-Mass Spectra (GC-MS), komponen utama dari minyak cengkeh adalah eugenol. Eugenol berperan terhadap aktivitas antibakteri pada edible film. Semakin tinggi konsentrasi minyak cengkeh, semakin tinggi daya hambat bakteri. Edible film dengan penambahan minyak cengkeh 3% memiliki daya hambat bakteri yang tertinggi yaitu 8,5 mm untuk bakteri Escherichia coli dan 11,3 mm untuk bakteri Staphylococcus aureus. Tingkat kelarutan edible film menurun seiring dengan penambahan minyak cengkeh yaitu 78,77%-39,38%. Penambahan minyak cengkeh pada pembuatan edible film berbasis pati mampu menghambat pertumbuhan bakteri Staphylococcus aureus dan Eschericia coli. Namun, semakin tinggi penambahan minyak cengkeh akan menurunkan tingkat kelarutan edible film.

LCYB merupakan gen yang memproduksi enzim Lycopene Beta Cyclase. Enzim Lycopene Beta Cyclase beperan dalam mengubah likopen menjadi ß-karoten. Gen LCYB terdapat pada diatom maupun mikroalga hijau. Berbeda dengan mikroalga hijau, penelitian mengenai struktur protein Lycopene Beta Cyclase selaku produk gen LCYB pada diatom masih minim publikasi. Dalam penelitian ini dilakukan prediksi struktur produk gen LCYB pada diatom P. tricornutum secara bioinformatika. Untuk menganalisis perbedaan produk gen LCYB pada diatom dan mikroalga hijau, produk gen LCYB pada diatom P. tricornutum dibandingkan dengan produk gen LCYB pada mikroalga hijau M. zofingiensis. Konstruksi pohon filogenetik dilakukan menggunakan perangkat lunak MEGA7. Analisis gen LCYB dan struktur produk gen LCYB dilakukan menggunakan beberapa perangkat bioinformatika. Analisis docking dilakukan untuk memperkuat prediksi adanya interaksi antara produk gen LCYB hasil prediksi dengan ligannya menggunakan AutoDocksTools-1.5.6. M. zofingiensis memiliki hubungan kekerabatan yang jauh dengan P. Tricornutum sehingga kemiripan gen dan produk gen LCYB hasil prediksi juga jauh berbeda. Mikroalga hijau M. zofingiensis mengandung protein transmembran yang tidak dimiliki pada diatom P. Tricornutum. Hasil docking menunjukkan adanya interaksi antara produk gen LCYB hasil prediksi dengan ligannya yaitu likopen.

Telah dilakukan kajian pengaruh kalibrasi peralatan pengujian moisture and impurities (M&I) dan deterioration of bleachability index (DOBI) pada crude palm oil (CPO). Kalibrasi berfokus pada neraca analitik dan spektrofotometer UV-Visibel sebagai bagian persyaratan dari sertifikasi Laboratorium Pengujian ISO/IEC 17025:2017. Penilaian kondisi neraca analitik berpedoman pada dua acuan yaitu Organisation Internationale De Métrologie Légale (OIML R 111-1 Edition 2004) dan The United States Pharmacopeial Convention (USP-41). Hasil kalibrasi neraca analitik Ohaus PA224 menggunakan anak timbangan kelas E2 (20-200 g) yang menghasilkan nilai koreksi kurang dari 0,1% dan sesuai persyaratan USP-41. Hasil kalibrasi neraca terhadap perhitungan ketidakpastian pengukuran moisture sangat kecil yaitu 0,0031% dan 0,0032% serta pengukuran impurities sebesar 0,00991% dan 0,01039%. Sementara kalibrasi spektrofotometer UV-Visibel didasarkan pada The United States Pharmacopeial Convention (USP-40) bagian 857 terkait Ultraviolet-Visible Spectroscopy menggunakanan bahan acuan tipe NIST neutral density standards. Hasil kalibrasi dengan nilai ketidakpastian (U95), k =2 untuk semua filter dan panjang gelombang sebesar 0,005-0,008 yang memiliki rata-rata sebesar 0,00545 yang memenuhi persyaratan absorbansi tidak melebihi ± 0,008. Hasil kalibrasi spektrofotometer UV-Visibel memberikan persentase nilai ketidakpastian analisis DOBI pada sampel CPO sebesar 2,3% untuk kedua sampel dimana hasil evaluasi ketidakpastian menunjukkan pengujian DOBI pada sampel CPO adalah baik karena memiliki nilai persentase ketidakpastian kurang dari 10%.

MOFs (Metal Organic Frameworks) telah banyak dilaporkan berhasil diaplikasikan dalam berbagai bidang salah satunya fotokatalitik. MOFs tersusun dari ion logam atau cluster oksida logam, senyawa penghubung organik (linker), serta senyawa lain sebagai senyawa tamu (guest) yang memberikan banyak keunggulan jika digunakan sebagai material fotokatalis. Kemampuan menyerap foton dari cahaya serta porositas yang baik menyebabkan MOFs menarik untuk diaplikasikan sebagai fotokatalis. Kestabilan sifat kimia yang kurang baik dan tidak begitu sensitif terhadap sinar tampak menjadi pokok persoalan yang membuat MOFs masih mengalami banyak perkembangan. Berbagai metode dilakukan dengan memodifikasi ion logam, linker, maupun pada senyawa tamu untuk mendapatkan material MOFs dengan kestabilan sifat kimia yang baik, peningkatan luas area permukaan, dan mampu menyerap banyak sinar pada daerah tampak.

Reaksi penataan ulang Claisen merupakan salah satu reaksi penting untuk pembentukan ikatan baru karbon-karbon dalam sintesis organik. Secara umum, reaksi penataan ulang Claisen hanya dapat berlangsung dalam kondisi reaksi yang cukup ekstrim yaitu suhu yang tinggi 180-225oC dengan waktu yang lama. Dalam penelitian ini dilakukan sintesis alil 1-naftil eter terlebih dahulu melalui reaksi substitusi gugus alil pada senyawa 1-naftol dengan pemanasan pada suhu 58oC selama 8 jam. Produk reaksi alilasi dianalisis kemurniannya dengan menggunakan HPLC dan H-NMR. Selanjutnya, reaksi penataan ulang Claisen pada senyawa hasil sintesis alil 1-naftil eter berhasil dilakukan pada suhu reaksi yang rendah dan waktu yang singkat menggunakan metode Microwave Assisted Organic Synthesis(MAOS) dan katalis FeCl3. Karakterisasi menggunakan GC-MS menunjukkan senyawa yang terbentuk adalah 2-alil-1-naftol (produk penataan ulang Claisen), 2-metil-2,3-dihidronaftofuran (produk siklisasi) dan 1-naftol sebagai produk balik. Hasil penelitian menunjukkan bahwa reaksi penataan ulang Claisen dan siklisasi pada senyawa alil 1-naftil eter berlangsung optimum dengan menggunakan pelarut 1,2-dikloroetana pada suhu 80oC selama 20 menit dengan radiasi microwave.

Critical quality control on the determination of boron using ICP-EOS with gravimetric method is carried out. This study was conducted to examine the critical aspects which include linearity, LOD, LOQ, precision, and accuracy. Based on the results of the study showed that the determination of boron with the ICP-OES method was following the critical aspects of quality control test results. The linearity of the calibration curve with a concentration range of 0 - 10 mg/L has linearity with a correlation coefficient of 0.9998 and a determination coefficient of 0.9996. The standard solution calibration curve follows the linear regression equation y = 2567.5 x + 23.043. This method has a LOD of 1.24 mg/L and a LOQ of 4.13 mg/L. The ICP-OES method has high precision and accuracy at low, medium, and high concentration levels. The testing precision of low, medium and high concentration levels is 0.44, 0.54, and 0.14%. The accuracy obtained for the three concentration levels was 98.03, 95.05, and 98.61%. Based on the ANOVA test, it was shown that the precision and accuracy at all concentration levels were not significantly different.

Waste management at tourist sites is an unavoidable problem due to the massive number of visitors. One of the types of waste is polyethylene terephthalate (PET) plastic bottles. This study aims to analyze the potential use of PET for waste to energy in tourist areas. This research was conducted in a tourist area in Klungkung Regency, Bali Province. This study only uses grab sampling in measuring waste generation and composition. This research was conducted by proximate analysis and thermal gravimetry analysis (TGA). The measurement of waste generation shows that the PET produced is 1.24 kg/day, or about 43.5% of the total waste generation. Proximate analysis measurements show the value of moisture, ash, volatile, and fixed carbon content, which are 1.53, 0.14, 95.92, and 2.42, respectively. Meanwhile, the caloric value of PET waste is 22.71 MJ/kg. The residue from the TGA results showed 2.575%. The thermal degradation process starts at a temperature of 280ᵒC, and the initial temperature of degradation starts at 406 – and ends at 468ᵒC. Utilization of PET waste at this tourist location can also help the purpose of waste management in Klungkung Regency, namely implementing the Waste to Energy concept at the Local Waste Processing Facility (TOSS).

Perbandingan metode penentuan sitronelal dalam minyak sereh ini dilakukan untuk mengetahui perbandingan metode kromatografi gas detektor FID dengan kromatografi gas detektor MS. Kandungan sitronelal dalam sampel minyak sereh wangi yang diperoleh dengan detektor FID serta detektor MS masing-masing sebesar 49,34% dan 42,97%. Metode kromatografi gas detektor FID dan detektor MS memiliki nilai presisi yang baik dengan nilai %RSD kurang dari 2% yaitu sebesar 0,295% dan 1,114%. Hasil uji t diperoleh nilai t hitung > t tabel yang artinya Ho ditolak dan Hi diterima. Hasil uji t menunjukkan bahwa kedua metode memberikan hasil yang berbeda secara signifikan terhadap kandungan sitronelal dalam minyak sereh wangi tetapi masih dapat diterapkan pada laboratorium.

Ikan Bandeng (Chanos chanos) merupakan ikan yang sering dikonsumsi oleh masyarakat karena harganya yang murah dan bergizi tinggi. Ikan bandeng dapat tercemar logam timbal (Pb) karena akumulasi dari pencemaran limbah industri dan kapal-kapal pada habitat ikan bandeng, serta paparan udara yang tercemar logam Pb yang kemudian terakumulasi dalam tubuh ikan bandeng. Penelitian ini bertujuan untuk mengetahui efektivitas penurunan kadar logam Pb dalam bandeng setelah direndam dengan air perasan jeruk nipis. Analisis kadar logam Pb dalam bandeng dapat digunakan metode Spektrofotometri Serapan Atom (SSA). Penetapan kadar logam Pb dalam bandeng dilakukan dengan merendam ikan bandeng dalam air perasan jeruk nipis kemudian mendestruksi sampel ikan bandeng dengan cara diabukan menggunakan furnace dan dilarutkan dengan HNO3 pekat lalu diaddkan dengan aquabidest. Larutan yang diperoleh kemudian diukur absorbansinya dengan metode Spektrofotometri Serapan Atom pada panjang gelombang 283,31 nm. Berdasarkan hasil penelitian dapat diketahui bahwa konsentrasi logam Pb dalam ikan bandeng asli yaitu sampel I 0.4288 mg/kg; sampel II 0.4873 mg/kg; dan sampel III 0.5653 mg/kg. Dalam sampel artificial sebelum direndam dengan air perasan jeruk nipis diperoleh kadar logam Pb dalam sampel I, II, dan III yaitu 3.9376 mg/kg; 4.3275 mg/kg; dan 3.5477 mg/kg. Sedangkan kadar Pb dalam sampel artificial yang telah direndam dengan air perasan jeruk nipis mengalami penurunan yang cukup signifikan yaitu 0.6238 mg/kg; 0.7407 mg/kg; dan 0.6043 mg/kg dengan efektivitas penurunan lebih dari 80%.