https://ejurnal.undana.ac.id/index.php/CN <hr> <p><img style="float: left; margin-left: 10px; margin-right: 10px;" src="/public/site/images/Nursalim/CN.jpg" alt="" width="107" height="135"></p> <p style="text-align: right;"><strong>e-ISSN: 2622-1071</strong></p> <p style="text-align: right;">&nbsp;</p> <p style="text-align: justify; line-height: 2em;">Chemistry Notes, published by Universitas Nusa Cendana, is a peer-reviewed journal focusing on original research(es) in chemistry, applied chemistry and educational chemistry. This bilingual journal (in English or in Bahasa Indonesia) is issued in 2 (two) volumes (June and December) every year. &nbsp;&nbsp;</p> <p>&nbsp;</p> <hr> Universitas Nusa Cendana en-US Chemistry Notes 2622-1071 <p>In order to publish in Chemistry Notes, authors are required to agree to the copyright permission stating that the authors give the publisher the right to reproduce, display or distribute the accepted manuscript. In this agreement the authors also automatically declare that the submitted manuscript is exempted from plagiarism issue and conflict of interest among the authors.</p> https://ejurnal.undana.ac.id/index.php/CN/article/view/14369 <p>Research has been conducted with the title Utilization of Silica Gel from the processing of TiO₂-Modified Corn Cob Ash to Reduce Nitrate Levels in Tofu Liquid Waste. This study aims to determine the characteristics of silica gel from the processing of TiO₂-modified corn cob ash in terms of functional groups and crystallinity and to determine the effectiveness of TiO₂-modified silica gel to reduce nitrate levels in tofu liquid waste using pH, time and concentration parameters. The synthesis of silica gel from corn cob ash was carried out using the sol gel method. The results of FTIR characterization showed the successful synthesis of silica gel and TiO₂modified silica gel indicated by the presence of Si-O-Si and Si-OH absorption in silica gel and Ti-O-Ti absorption in TiO₂ modified silica gel. The XRD data shows that silica gel has an amorphous structure and modified silica gel has an anatase structure. The results showed that the largest nitrate reduction occurred at pH 5 by 98.69%, contact time of 60 minutes by 97.39% and optimum concentration of 200 ppm by 98.94% with the largest silica adsorption capacity of 245.94 mg/g and the percentage of nitrate reduction in tofu liquid waste by 99.94%.</p> Theodore Y. K. Lulan Intan C. M. Ndolu Fidelis Nitti ##submission.copyrightStatement## 2023-12-22 2023-12-22 5 2 1 12 https://ejurnal.undana.ac.id/index.php/CN/article/view/14370 <p>Aromatic aldehydes including chalcones are known to have various biological activities. Such compound i.e. 2,4,5-trimethoxybenzaldehyde has also proven to be a COX-II inhibitor anti-inflammation and colon and breast cancer chemoprotective agent. This study aims to determine the toxicity of 2,4,5-trimethoxybenzaldehyde against <em>artemia salina</em> L. larvae according to the Brine Shrimp Lethality Test (BSLT) method. The results showed that the 2,4,5-trimethoxybenzaldehyde has a toxic effect with its LC₅₀is 70.12 µg/mL</p> Reinner I. Lerrick Paskalia A. Ximenes Suwari Suwari ##submission.copyrightStatement## 2023-12-22 2023-12-22 5 2 13 22