Silaen, Gabriella Natasha (2026) Studi Komparatif Reduksi Fe³⁺ Menjadi Fe²⁺ Menggunakan Hidroksilamin Hidroklorida, Natrium Sulfit, Dan Ekstrak Gambir (Uncaria gambir (W.Hunter) Roxb.) Dengan Ion Pengganggu Ni²⁺. Other thesis, Institut Teknologi Sepuluh Nopember.
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Abstract
Penelitian mengenai reduksi Fe³⁺ menjadi Fe²⁺ memiliki peranan penting dalam berbagai aplikasi, seperti analisis kadar besi, penghilangan noda karat pada permukaan material, dan pengendalian mutu produk yang mengandung besi. Beberapa penelitian terdahulu telah mengkaji pengaruh ion pengganggu, seperti Mg²⁺, As³⁺, Mn²⁺, Ag⁺, dan ion logam lainnya, terhadap penentuan kadar besi menggunakan ligan 1,10-fenantrolin. Namun, informasi mengenai pengaruh Ni²⁺ terhadap kinerja beberapa jenis reduktor dalam mereduksi Fe³⁺ menjadi Fe²⁺ masih terbatas. Oleh karena itu, penelitian ini bertujuan untuk menganalisis pengaruh variasi konsentrasi Ni²⁺ terhadap kinerja hidroksilamin hidroklorida (NH₂OH·HCl), natrium sulfit (Na₂SO₃), dan ekstrak gambir (Uncaria gambir (W. Hunter) Roxb.) dalam mereduksi Fe³⁺ menjadi Fe²⁺. Kinerja masing-masing sistem dievaluasi berdasarkan hasil reduksi Fe³⁺ menjadi Fe²⁺ yang terukur relatif terhadap kondisi tanpa penambahan Ni²⁺ sebagai kontrol. Penentuan Fe²⁺ dilakukan melalui pembentukan kompleks Fe(II)-fenantrolin yang menghasilkan warna merah-oranye dan diukur menggunakan spektrofotometer UV-Vis pada panjang gelombang 510 nm. Konsentrasi reduktor terpilih berdasarkan optimasi konsentrasi untuk NH₂OH·HCl, Na₂SO₃, dan ekstrak gambir berturut-turut sebesar 7, 40, dan 10 ppm. Pada kondisi penelitian yang digunakan, persentase hasil reduksi yang diperoleh masing-masing sebesar 78,35%, 69,30%, dan 86,35%, dengan nilai kemiringan kurva reduksi berturut-turut sebesar 0,1000; 0,0677; dan 0,1041. Penambahan Ni²⁺ menurunkan hasil reduksi pada seluruh sistem dengan pola yang berbeda. Penurunan tajam mulai terlihat pada rentang konsentrasi Ni²⁺ 1–2 ppm dalam sistem ekstrak gambir serta 2–3 ppm dalam sistem NH₂OH·HCl dan Na₂SO₃. Pada konsentrasi Ni²⁺ sebesar 5 ppm, persentase perbandingan hasil reduksi terhadap kontrol pada sistem NH₂OH·HCl, Na₂SO₃, dan ekstrak gambir berturut-turut sebesar 57,3%, 44,5%, dan 38,6%. Hasil penelitian menunjukkan bahwa pada kondisi pengujian yang digunakan, sistem ekstrak gambir menghasilkan persentase reduksi lebih tinggi dibandingkan kedua reduktor lainnya, sedangkan sistem NH₂OH·HCl mengalami penurunan persentase perbandingan hasil reduksi terhadap kontrol yang lebih kecil akibat penambahan Ni²⁺. Dengan demikian, ketiga reduktor menunjukkan karakteristik reduksi dan respons terhadap Ni²⁺ yang berbeda.
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The reduction of Fe³⁺ to Fe²⁺ plays an important role in various applications, including iron determination, rust-stain removal from material surfaces, and quality control of iron-containing products. Previous studies have investigated the effects of interfering ions, such as Mg²⁺, As³⁺, Mn²⁺, Ag⁺, and other metal ions, on iron determination using 1,10-phenanthroline as a ligand. However, information regarding the effect of Ni²⁺ on the performance of different reducing agents in the reduction of Fe³⁺ to Fe²⁺ remains limited. Therefore, this study aimed to evaluate the effect of varying Ni²⁺ concentrations on the performance of hydroxylamine hydrochloride (NH₂OH·HCl), sodium sulfite (Na₂SO₃), and gambir extract (Uncaria gambir (W. Hunter) Roxb.) in reducing Fe³⁺ to Fe²⁺. The performance of each system was evaluated based on the measured reduction yield relative to the condition without Ni²⁺ addition, which was used as the control. Fe²⁺ was determined through the formation of a red-orange Fe(II)–phenanthroline complex, whose absorbance was measured by UV–Vis spectrophotometry at 510 nm. Concentration optimization resulted in selected reducing-agent concentrations of 7, 40, and 10 ppm for NH₂OH·HCl, Na₂SO₃, and gambir extract, respectively. Under the experimental conditions, the corresponding reduction yields were 78.35%, 69.30%, and 86.35%, with reduction-curve slopes of 0.1000, 0.0677, and 0.1041, respectively. The addition of Ni²⁺ decreased the measured reduction yield in all systems, although the patterns of decline differed among the reducing agents. A pronounced decrease was observed within the Ni²⁺ concentration range of 1–2 ppm in the gambir extract system and 2–3 ppm in the NH₂OH·HCl and Na₂SO₃ systems. At a Ni²⁺ concentration of 5 ppm, the reduction yields relative to their respective controls were 57.3%, 44.5%, and 38.6% for the NH₂OH·HCl, Na₂SO₃, and gambir extract systems, respectively. Under the experimental conditions, the gambir extract system produced a higher reduction yield than the other two systems, whereas the NH₂OH·HCl system exhibited a smaller relative decrease in reduction yield following Ni²⁺ addition. These findings indicate that the three reducing agents exhibit distinct reduction characteristics and responses to Ni²⁺ interference.
| Item Type: | Thesis (Other) |
|---|---|
| Uncontrolled Keywords: | Fe³⁺/Fe²⁺; 1,10-fenantrolin; NH₂OH·HCl; Na₂SO₃; gambir. |
| Subjects: | Q Science > QD Chemistry > QD117.S64 Spectrophotometry |
| Divisions: | Faculty of Science and Data Analytics (SCIENTICS) > Chemistry > 47201-(S1) Undergraduate Thesis |
| Depositing User: | Gabriella Natasha Silaen |
| Date Deposited: | 30 Jul 2026 01:18 |
| Last Modified: | 30 Jul 2026 01:18 |
| URI: | http://repository.its.ac.id/id/eprint/140266 |
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