Zulhan Arif
Departemen Kimia Fakultas Matematika Dan Ilmu Pengetahuan Alam IPB University

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Antioxidant Capacity, Total Phenolic, and Flavonoid Content from Java Tea (Orthosiphon aristatus) Extracts Zulhan Arif; Aurentinus Zalukhu; Alfi Hudatul Karomah; Mohamad Rafi
Jurnal Jamu Indonesia Vol. 7 No. 3 (2022): Jurnal Jamu Indonesia
Publisher : Tropical Biopharmaca Research Center, IPB University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29244/jji.v7i3.268

Abstract

Orthosiphon aristatus, known as kumis kucing in Indonesia, has some biological activity, i.e., as an anti-inflammatory, fever, rheumatism, diabetes, and kidney stone. This plant is also known for being rich in phenolic compounds such as flavonoids. In this study, we would like to compare the antioxidant activity, total phenolics, and flavonoid content from the stems and leaves of Orthosiphon aristatus extracted with water and ethanol by maceration. The yield stem and leaves of the water extract are 12.98-31.28%, and ethanol extract 3.58 - 9.82% (dry basis). The stem and leaves water extract contains a phenolic of 7.82-26.43 (mg GAE/g) and ethanol extract of 2.27-7.84 (mg GAE/g). Water extract Orthosiphon aristatus flavonoid content is 1.23-2.86 (mg EK/g), and ethanol extract is 1.09-3.95 (mg EK/g). The antioxidant activity of ethanol (IC50), extract from leaves was 123.91 (µg/mL) and from stems was 125.50 (µg/mL), while IC50 of water extract from leaves was 114.70 (µg/mL) and from stems was 125.03 (µg/mL). The correlation test result of active compounds using linear regression is phenolic compounds with antioxidants stronger than flavonoids. The qualitative thin-layer chromatography fingerprint analysis showed that ethanol and water extract contained natural sinensetin compounds.
Preparation and Field Application of A Cellulose Triacetate–Based Optode for Cr(VI) Detection in Environmental Water Samples Zulhan Arif; Fendy; Fransisca Gunawan; Elsa Febriani; Sri Sugiarti; Eti Rohaeti; Irmanida Batubara
Indonesian Journal of Chemical Studies Vol. 4 No. 2 (2025): Indones. J. Chem. Stud. December 2025
Publisher : Indonesian Scholar Society

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.55749/ijcs.v4i2.147

Abstract

In this study, the optode was fabricated by incorporating 1,5-diphenylcarbazide and the ion carrier Aliquat 336 into a cellulose triacetate polymer matrix, which was subsequently modified using a dual-plasticizer system consisting of oleic acid and acetophenone. The successful synthesis of the optode was justified through FTIR spectroscopy to confirm functional group immobilization and screw micrometer measurements to ensure membrane thickness uniformity. A linear response was obtained within the concentration range of 0.02–0.40 ppm, with a determination coefficient (R²) of 0.9979, a limit of detection of 0.0108 ppm, a limit of quantitation of 0.0328 ppm, precision expressed as a relative standard deviation of 4.458%, and accuracy of 97.51%. The optode demonstrated high analytical sensitivity, as evidenced by a molar absorptivity of 2.262 × 10⁷ M⁻¹ cm⁻¹, along with excellent selectivity against common potentially interfering ions, including Fe(III), Pb(II), Zn(II), and Cd(II). The formed color complex exhibited good stability, remaining unchanged for up to five days. When applied to the determination of Cr(VI) in water samples, the optode yielded a concentration of 0.0664 ppm with satisfactory precision and accuracy. Although this value differed from the concentration obtained using UV–Vis spectrophotometry (0.0881 ppm), the overall performance of the optode was validated. Furthermore, a functional prototype was successfully developed and evaluated using real samples, producing favorable results. Collectively, these outcomes highlight the strong potential for further development and optimization of the proposed system.
Validation Method of the Cellulose Triacetate-Based Optode Membrane for Fe(III) Detection in Water Samples Zulhan Arif; Sri Sugiarti; Eti Rohaeti; Irmanida Batubara
Jurnal Kimia Sains dan Aplikasi Vol 28, No 3 (2025): Volume 28 Issue 3 Year 2025
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/jksa.28.3.146-154

Abstract

Iron contamination in water is a threat to human health and the environment. This contamination requires a fast and efficient detection method. Method validation is integral to method development, ensuring alignment with the intended objectives. This research aims to validate a method for selective detection of Fe(III) based on cellulose triacetate (CTA) optode membrane. The optode membrane was prepared by mixing CTA, plasticizers, Aliquat-336, and thiocyanate as selective reagents. The validation of the optode membrane was evaluated based on validation performance parameters. The Fe(III) optode membrane detection demonstrated a linear response with a determination coefficient of 0.9972 within a concentration range of 0.1–4.0 mg/L, the detection limit of 0.0553 mg/L, quantitation limit of 0.1676 mg/L, precision 3.01%, intermediate precision of 3.03% and 3.01%, the accuracy of 101.62%. The optode membrane exhibited good selectivity with a value of -0.4580 and -0.2748 against Pb(II) and Cr(VI), respectively, sensitivity of 1.05 × 107 M-1 cm-1 and color formation stability %RSD of 3.14%. The application of real samples shows no significant difference between the UV-Vis spectrophotometry and optode membrane methods at a 95% confidence level (α = 0.05). The validation results offer a valuable perspective into whether this method can be adopted as a new approach or as an alternative to existing methods for cation analysis in water samples.
Biochemical and gene expression analysis for the selection of elite oil palm ortets Irma Kresnawaty; Ludwinardo Putra; Heni Rahmawati; Zulhan Arif; Masna Maya Sinta; Rizka Tamania Saptari; Fauziatul Fitriyah; Heri Adriwan Siregar; Imron Riyadi
E-Journal Menara Perkebunan Vol. 94 No. 1 (2026): 94(1), 2026
Publisher : INDONESIAN RESEARCH INSTITUTE FOR BIOTECHNOLOGY AND BIOINDUSTRY

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22302/iribb.jur.mp.v94i1.676

Abstract

The rising global demand for palm oil necessitates innovative strategies to accelerate yield improvement and ensure sustainable production. Conventional propagation methods are limited by long regeneration cycles, making tissue culture a more practical alternative that relies on elite ortet identification. This preliminary study aimed to evaluate crude palm oil quality, leaf metabolite profiles, and gene expression as early indicators for selecting elite ortets. Mature fruits were used to assess oil yield, free fatty acid, and β-carotene contents, while leaves were analyzed for chlorophyll and total phenolic content. Based on biochemical screening, three candidate ortets were further evaluated for the expression of acetyl-CoA carboxylase (ACCase) and phytoene synthase (PSY) genes. Oil yield ranged from 77-83%, FFA 5-9%, and β-carotene 200-450 mg kg-1 CPO across candidates. Candidate 3.7 exhibited the highest oil yield and elevated ACCase expression, while candidate 6.12 showed the highest β-carotene content and PSY expression. Candidate 5.7 demonstrated relatively low FFA and favorable chlorophyll levels. These results suggest an association between ACCase expression and oil yield, as well as between PSY expression and β-carotene accumulation. Collectively, these findings support a proof-of-concept for an integrated profiling strategy to select elite ortets for advanced tissue culture propagation.