Indonesian Journal of Chemical Studies

Evaluation of Interlaboratory Comparisons on Quality Testing Towards Pesticide Formulation of beta-Cyfluthrin, Chlorpyrifos, and Profenofos Active Ingredients

2023-11-15T00:07:39+07:00

The Surabaya Center for Seed and Plantation Protection (BBPPTP Surabaya) carried out interlaboratory comparison research to test the quality of pesticide formulations. This study aimed to determine the ability of each participating laboratory to analyze the concentration of the active ingredients’ beta-cyfluthrin, chlorpyrifos, and profenofos in test samples expressed in z-score values. A total of 15 laboratories participated in this program. The quality test method of the pesticide formulations for the beta-cyfluthrin, chlorpyrifos, and profenofos active ingredients referred to the Association of Official Agricultural Chemists (AOAC) method, which was developed and validated. A homogeneity test was carried out before the test samples were distributed. The data were evaluated using a robust z-score statistical calculation algorithm, a method under the International Organization for Standardization (ISO) 13528:2016. The assigned values used to calculate the z-score were obtained by statistical processing of participants’ test results. The results of the stability test calculation showed that the distributed sample data was statistically stable. Three laboratory participants were in the questionable category, and one laboratory participant was in the outlier category.

Magnetically Chitosan-Silica-Based Biosorbent as Efficient Removal of Au(III) in Artificial Wastewater

2024-01-23T23:29:45+07:00

The synthesis of chitosan-modified silica-coated iron oxide magnetic material (Fe₃O₄/SiO₂/Chitosan) via the sol-gel process addresses the need for enhanced stability and functionality in various applications. Coating iron oxide magnetic material with chitosan-modified silica is a common strategy to improve biocompatibility and performance. This study investigates the synthesis of Fe₃O₄/SiO₂/Chitosan using sodium silicate as the silica precursor. The synthesis involved sonication of Fe₃O₄ and sodium silicate for 5 min, followed by adding chitosan in 4% acetic acid with continuous stirring. The mass ratio of Fe₃O₄:SiO₂ was fixed at 0.5:0.73, with varying chitosan masses (0.025, 0.050, and 0.075 g). Characterization techniques used included Fourier-Transform Infrared Spectroscopy (FTIR), X-ray powder Diffraction (XRD), and Thermogravimetric analysis (TGA). The product with the highest mass yield was further analyzed. The variation in the amount of chitosan in the conducted research aimed to determine the optimum chitosan mass that could still bind to the silica framework. Magnetite was confirmed as the primary composition, with the addition of chitosan and silica functional groups observed through vibration absorption characteristics. Thermogravimetric analysis showed differences in decomposition patterns between samples. The optimal chitosan content for characterization was determined at 0.050 g. Future applications might include enhanced adsorption processes owing to the optimized structure and composition of Fe₃O₄/SiO₂/Chitosan nanoparticles.

Simple Synthesis of Cellulose Triacetate from HVS Paper Waste and Its Application for Optode

2024-06-26T01:29:58+07:00

The optode membrane is a membrane that can identify ions in an aqueous solution. One of the most widely used optode membranes is cellulose triacetate based. Cellulose triacetate (CTA) has the characteristics of hydrophobic, transparent, elastic, and affordable. There are sources of cellulose triacetate that can be utilized and waste paper is one of them. Waste paper is extracted to obtain the cellulose, then by acetylization reaction to produce cellulose triacetate. The resultant cellulose triacetate has a degree of substitution (DS) of 2.89 and an acetyl group percentage (% AG) of 43.64. The standard and synthesized CTA optode membrane are tested for performance with various parameters, ie optimum pH, optimum immersion time, working range, limit of detection (LOD), and limit of quantification (LOQ). The standard CTA optode membranes and synthesized worked at pH 3 and 4 with optimum immersion time for 15 min, respectively. The optode produced a linear response in detecting Cr(VI) ion in the concentration range of 0.02-1 mg/L for standard CTA with an R² of 0.9726 and 1-25 mg/L for synthesized CTA with an R² of 0.9764, The limit of detection (LOD) and limit of quantitation (LOQ) were 0.0015 mg/L and 0.0051 mg/L for standard CTA, while 0.0224 mg/L and 0.0749 mg/L for synthesis CTA respectively. Since both optode membranes' performance test results are adequate, the synthesis results of CTA optode membranes can be employed as one source of cellulose triacetate.

Reaction Mechanism in Standardized α-Cellulose Content Test: Study from Boehmeria nivea Fiber

2024-06-19T23:38:29+07:00

In defense industry, α-cellulose is the main component of nitrocellulose propellant. However, a detailed description of the reaction mechanism of each treatment step in SNI 0444-2009 is still very scarce. This study addresses this gap by presenting the reaction mechanisms of each treatment and the symbols used in the SNI 0444-2009 procedure. The separation of lignin from α-cellulose occurred by breaking the C‒O bond linking them. This bond was broken by the ‒OH group of NaOH via a hydrolysis reaction. The reaction was initiated with the elimination of a hydrogen atom from the lignin structure by the hydroxyl ion (‒OH), and the C‒O bond was broken by a hydrolysis reaction. The breaking of this bond was indicated by the disappearance of the IR peaks at wavenumbers 1049 and 1190 cm^–1 in the filtrate after extraction. The SNI 0444-2009 method for the α-cellulose content test was carried out by a redox back titration of Cr(VI) with Fe(II) from ferrous ammonium sulfate. This titration was conducted to calculate the amount of Cr(VI) ions in potassium dichromate or Cr(VI) that did not react with lignin or beta cellulose in the filtrate. Understanding the contribution and reaction mechanisms of each compound involved in the SNI 0444-2009 procedure contributed to obtaining accurate data on α-cellulose content. In this study, the calculated α-cellulose content of the flax fiber was 96.75%. Furthermore, the detailed mechanism of the redox reaction was discussed in detail in this paper.

Light Pyrotechnics Using Gunpowder Derived from Fly Ash Bottom Ash (FABA) Waste and Activated Carbon

2024-04-06T16:00:19+07:00

Pyrotechnic materials are a category of materials that are often used in various applications, including military activities, lighting, signaling, and combat effects. In this study, an experiment was conducted to create a light pyrotechnic material using gunpowder, which is a mixture of potassium nitrate, sulfur, and activated carbon. The manufacturing process involved the activation of carbon from fly ash bottom ash (FABA) waste and the composition of different pyrotechnic materials. The experiment involved testing pyrotechnic compositions with varying ratios of KNO₃ : carbon : sulfur. The results showed that the composition with a ratio of 15 : 7.5 : 7.5 produced the highest light intensity, reaching 104 lux, and provided optimal visual effects. In addition, the relative proportions of oxidizer, carbon and sulfur affected the type of pyrotechnic effect produced. Pyrotechnic light generation from gunpowder could be considered successful, and the best composition for spectacular visual effects was a ratio of 15 : 7.5 : 7.5. However, sufficient caution and knowledge were required in the use of pyrotechnic materials to ensure safety and compliance with applicable regulations.

Temperature-influenced Bulk Emulsion (BE) Demulsification Method as a PIBSA-MEA Emulsifier Durability Test in Blasting Environments under 100 °C

2024-04-15T23:04:30+07:00

This research attempts to provide a better method, examine more effective temperatures for testing emulsifiers, and determine the demulsification limit that indicates emulsifier durability. This experiment was conducted by varying the temperature (40, 60, 80, and 100 °C) for heating the product with a test time of 1, 2, 4, and 6 h, then detected using formaldehyde titration to determine the highest level of demulsification of ammonium nitrate (AN) salt at each temperature in the product. The results showed that 100 °C was the most effective and representative temperature for testing the durability of the emulsifier with the highest level of demulsification from the other temperatures. This was indicated by the weight of AN salt that came out of the emulsion reaching 2.05 g from 20 g of emulsion or about 10.25% of the total weight of the product within 6 h. Emulsifiers with AN levels below 2.05 g (10.25%) were considered to pass the test and could be used for further production or analysis. This new test method was expected that bulk emulsion manufacturers would be faster in eliminating PIBSA-base (Polyisobutylene succinic anhydride-base) emulsifier products widely used by emulsifier manufacturers in manufacturing BE. This was due to it only focusing on the ability of emulsifiers to hold the product in high-temperature exposure so that it remained unified and not demulsified.