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"ABSTRACTLabel indikator kolorimetrik telah banyak dikembangkan dari segi material maupun aplikasinya. Pendeteksian uap asam asetat dengan label indikator kolorimetrik didasarkan pada perubahan warna label yang terjadi akibat interaksi uap asam asetat dengan zat warna. Label dibuat dengan menggunakan ekstrak beras hitam dan bunga kangkung laut yang diimobilisasikan pada substrat kertas. Jenis ekstrak dan substrat, kosentrasi asam asetat 20, 40, 60, 80 dan 100, pH larutan 9 dan 13, dan waktu pendeteksian menjadi variabel yang akan divariasikan pada pengujian label dengan uap asam asetat. Rentang perubahan warna akibat kenaikan pH pada larutan ekstrak bunga kangkung laut lebih luas dibandingkan ekstrak beras hitam, yang mencakup seluruh spektrum warna cahaya tampak. Jenis label yang memiliki respons perubahan warna yang paling terlihat jelas adalah label dari substrat Kalkir dan ekstrak bunga kangkung laut yang dikondisikan pada pH 9. Warna label ini berubah dari hijau menjadi kemerahan setelah dipaparkan pada uap asam asetat. Perubahan warna akan semakin merah dan semakin cepat seiring kenaikan kosentrasi. Hasil pengujian stabilitas warna label menunjukan bahwa label baik disimpan di suhu rendah dan pada kelembaban relatif 55.

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ABSTRACTThe indicator label based on the colorimetric method has been widely developed in terms of both materials and applications. The detection of acetic acid vapor using colorimetric indicator label is based on color change results from the interaction of acetic acid vapors with the dyes. Labels are made using black rice extract and morning glory flowers immobilized into paper substrate. Variables varied in this measurement are extract sources, substrate types, acetic acid concentrations 20, 40, 60, 80 and 100, solution pH 9 and 13, and detection time. The ranges of color change due to the increase in pH of the morning glory flower extract solution are wider than the black rice extract solution, which covers the entire visible color spectrum. It was observed that the type of label that has the most noticeable color change response is a label made from tracing paper and a morning glory flower extract conditioned at pH 9. The color of this label changes from green to reddish green after exposure to acetic acid vapors. Color changes will accelerate and become redder along with the increase in concentration of acetic acid solution. The result of labels color stability test indicates that the label is well kept at low temperature and at 55 relative humidity."

"Indonesia merupakan salah satu negara pengekspor besar minyak kelapa sawit. Dalam proses pengolahan kelapa sawit menjadi minyak kelapa sawit terutama pada proses deodorisasi menggunakan suhu tinggi, cenderung terbentuk zat 3-monochloropropanaediol (3-MCPD) yang berbahaya bagi kesehatan sehingga harus dideteksi dan dihilangkan. Metode pengujian kandungan zat 3-MCPD yang sudah umum digunakan yaitu GC-MS, namun GC-MS ini mahal, prosesnya kompleks, dan waktu pengujian lama, sehingga dibutuhkan metode alternatif. Penelitian ini menunjukkan metode baru, sederhana, dan efisien untuk tujuan aplikasi deteksi cepat 3-MCPD berbasis analisis kolorimetri dengan menggunakan nanopartikel tembaga. Nanopartikel disintesis menggunakan prekursor CuCl2, ligan L-Glutathione sebagai agen pelindung, dan reduktor hidrazin monohidrat. Nanopartikel hasil sintesis dikarakterisasi dengan UV-Vis, FTIR, dan PSA. Spektroskopi UV-Visible (UV-Vis) digunakan untuk memantau pita LSPR dari nanopartikel tembaga yang difungsikan L-Glutathione (GSH-CuNPs). Spektroskopi Fourier Transform Infrared (FTIR) memberikan informasi tentang interaksi permukaan antara L-Glutathione dan CuNPs. Penganalisis Ukuran Partikel (PSA) mengkonfirmasi ukuran rata-rata nanopartikel sebesar 57,43 nm. Setelah sintesis, GSH-CuNPs yang didapat diuji sebagai sensor kolorimetri untuk mengetahui keberadaan zat berbahaya 3-MCPD. Sensitivitas nanopartikel terhadap penambahan 3-MCPD 100, 50, 25, 10, dan 5 ppm dievaluasi pada penelitian ini

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Indonesia is one of the major exporters of palm oil. In the process of processing crude palm oil into palm oil, especially in the deodorization process using high temperatures, 3-monochloropropanediol (3-MCPD) substances are produced. The presence of this substance possesses health risks, so it must be detected and eliminated. The commonly used content testing method of 3-MCPD is GC-MS. However, this method is expensive, the process is complex, and the testing time is long. Therefore, an alternative method is needed. This study demonstrates a new, simple, and efficient method for the rapid detection of 3-MCPD based on colorimetric analysis using copper nanoparticles. The nanoparticles were synthesized using CuCl2 precursor, L-Glutathione ligand as a protective agent, and hydrazine monohydrate as a reducing agent. The synthesized nanoparticles were characterized by UV-Vis, FTIR, and PSA. UV-Visible (UV-Vis) spectroscopy was used to monitor the LSPR band of L-Glutathione-functionalized copper nanoparticles (GSH-CuNPs). Fourier Transform Infrared (FTIR) spectroscopy provides information on the surface interactions between L-Glutathione and CuNPs. The Particle Size Analyzer (PSA) confirmed the average nanoparticle size of 57.43 nm. After synthesis, the obtained GSH-CuNPs were tested as colorimetric sensors to determine the presence of the hazardous substance 3-MCPD. The sensitivity of nanoparticles to the addition of 3-MCPD 100, 50, 25, 10, and 5 ppm was evaluated in this study"

"Merkuri merupakan salah satu logam berat yang dapat ditemukan di perairan baik air tawar maupun air laut dan memiliki toksisitas yang tinggi sehingga penyebarannya perlu dikendalikan. Telah ditemukan bahwa nanopartikel emas yang terkonjugasi asam sianurat memiliki kemampuan untuk mendeteksi Hg2+ dengan prinsip kolorimetri. Oleh karena itu, penilitian ini bertujuan untuk mengembangkan metode deteksi merkuri yang sensitif dan selektif menggunakan nanopartikel emas terkonjugasi asam sianurat dalam perangkat berbasis kertas. Kondisi optimum dalam preparasi kertas saring untuk menghasilkan sensor yang paling baik yaitu dengan menggunakan kertas saring Whatman No. 1 yang direndam dalam larutan AuNP terkonjugasi asam sianurat selama 24 jam dan pengeringan pada suhu 50oC selama 10 menit. Analisis dilakukan setelah perangkat kertas diteteskan sampel sebanyak 20 µL sehingga terjadi perubahan warna yang jelas dari merah muda ke warna ungu kebiruan setelah 5 menit. Deteksi dapat diamati secara visual dengan mata telanjang hingga konsentrasi Hg2+ yang cukup kecil yaitu 0,05 µM. Respon kolorimetri sensor juga selektif terhadap Hg2+ setelah dilakukan pengujian dengan ion-ion logam Ba2+, Zn2+, Cd2+, Mn2+, Cu2+, Mg2+, Ag2+, dan Fe2+. Selain itu, respon dari sensor juga konsisten untuk sampel air danau yang dibubuhi Hg2+. Hasil dari penelitian ini yaitu dapat memberikan teknologi dasar yang menjanjikan untuk pengembangan sensor yang terjangkau, cepat, portabel, dan mudah digunakan untuk deteksi dan pemantauan kadar Hg2+ dalam air.

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Mercury is one of the heavy metals that can be found in both fresh water and sea water and has high toxicity so that its spread needs to be controlled. It has been found that gold nanoparticles conjugated with cyanuric acid have the ability to detect Hg2+ by the colorimetric principle. Therefore, this research aims to develop a sensitive and selective mercury detection method using cyanuric acid-conjugated gold nanoparticles in a paper-based device. The optimum condition for preparing filter paper to produce the best sensor is using Whatman No. filter paper. 1 which was soaked in AuNP solution which had been conjugated with cyanuric acid for 24 hours and dried at 50oC for 10 minutes. Analysis was carried out after 20 µL of sample was dropped on the paper device so that there was a clear color change from pink to bluish-purple after 5 minutes. Detection can be observed visually with the naked eye down to a fairly small Hg2+ concentration of 0.05 µM. The colorimetric response of the sensor is also selective towards Hg2+ after testing with metal ions Ba2+, Zn2+, Cd2+, Mn2+, Cu2+, Mg2+, Ag2+, and Fe2+. In addition, the response from the sensor is also consistent for lake water samples spiked with Hg2+. The results of this research can provide a promising basic technology for the development of sensors that are affordable, fast, portable, and easy to use for the detection and monitoring of Hg2+ levels in water.Mercury is one of the heavy metals that can be found in both fresh water and sea water and has high toxicity so that its spread needs to be controlled. It has been found that gold nanoparticles conjugated with cyanuric acid have the ability to detect Hg2+ by the colorimetric principle. Therefore, this research aims to develop a sensitive and selective mercury detection method using cyanuric acid-conjugated gold nanoparticles in a paper-based device. The optimum condition for preparing filter paper to produce the best sensor is using Whatman No. filter paper. 1 which was soaked in AuNP solution which had been conjugated with cyanuric acid for 24 hours and dried at 50oC for 10 minutes. Analysis was carried out after 20 µL of sample was dropped on the paper device so that there was a clear color change from pink to bluish-purple after 5 minutes. Detection can be observed visually with the naked eye down to a fairly small Hg2+ concentration of 0.05 µM. The colorimetric response of the sensor is also selective towards Hg2+ after testing with metal ions Ba2+, Zn2+, Cd2+, Mn2+, Cu2+, Mg2+, Ag2+, and Fe2+. In addition, the response from the sensor is also consistent for lake water samples spiked with Hg2+. The results of this research can provide a promising basic technology for the development of sensors that are affordable, fast, portable, and easy to use for the detection and monitoring of Hg2+ levels in water."