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1	Analytical Chemistry	ABS-17
Effect of Casting Temperature on the Swelling Degree and Water Content of Agarose Crosslinked with Oxalic Acid as DGT Diffusion Layer Layta Dinira, 1) Barlah Rumhayati, 1) Ulfa Andayani, 1) and Diah Mardiana 1) 1) Department of Chemistry, Faculty of Mathematics and Natural Sciences, University of Brawijaya, Indonesia Abstract Diffusive Gradient in Thin Films (DGT) is an in situ passive sampling technique that employs a sampler comprised of a hydrogel-based diffusion layer. Agarose can be used as a substitute for polyacrylamide hydrogels. Due to its large pore, agarose should be cross-linked with oxalic acid to make the separation of analyte more selective. Agarose was cross-linked with oxalic acid by adding a solution of agarose and a solution of oxalic acid (50 percent weight of agarose) at 60 oC. The mixture was stirred, poured into a mold, and heated in an oven for 15 minutes at a casting temperature of 40, 50, and 60 oC. The gels were soaked for one, two, three, and up to twenty-four hours after being rinsed with distilled water. At each immersion period, the mass, length, width, and thickness of the gel were measured. The swelling degree of the hydrogel was calculated by comparing the mass before and after immersion. The gravimetric method was used to determine the water content. The results indicated that the swelling degree of agarose cross-linked with oxalic acid after a 24-hour immersion at temperatures of 50 and 60 oC was not significantly different. However, the swelling degree of the gel from both casting temperatures was considerably different from 40 oC. The water content of hydrogels made at 40, 50, and 60 oC differed considerably from non-crosslinked agarose. Keywords: DGT diffusion layer, agarose, oxalic acid, swelling degree, water content Share Link | Plain Format | Corresponding Author (Layta Dinira)

2	Analytical Chemistry	ABS-34
Green Synthesis of Silver Nanoparticles using Coffea Canephora Fruit Skin Extract and Its Application for Mercury Detection in Face Cream Samples Hermin Sulistyarti, Muhammad Mashuri Utama, Ari Muchson Fadhila, Anggita Cahyaningrum, Revika Julia Murti, Ayu Febriyanti Chemistry Department, Faculty of Mathematics and Natural Sciences, Brawijaya University, Jl. Veteran 1, Malang, 65145, Indonesia LCAMIA: Research Centre for Low Cost and Automated Method & Instrumentation Analysis, Brawijaya University, Malang, 65145, Indonesia Abstract Mercury is one of the most toxic heavy metals causing harmful effects on the human body- meanwhile, mercury is found in some face cream products to give a whitening effect. The upper limit concentration of mercury in skin lightening product defined by the Food and Drug Administration (FDA) is under 1 ppm as Hg^{2+}. A new green analytical spectrophotometric method for mercury analysis has been developed by employing natural reagent from fruit skin extract of robusta coffee (Coffea canephora) as a bioreductor for silver ions as well as stabilizer for the AgNPs product. The detection principle of this method is based on based on the decrease of the colour intensity of silver nanoparticles (AgNPs) after the addition of Hg^{2+} ions due to the reoxidization of the AgNPs by Hg^{2+} ions to colorless Ag^{+} ions. To achieve the greatest sensitivity, linearity of measurement, and validity the method was optimized towards the volume of AgNPs and reaction time. In this research, the synthesized AgNPs were also characterized by UV-Vis Spectrometry as well as particle size analyzer (PSA) to determine the size of nanoparticles. The result showed that the optimum conditions were attained at 3 mL AgNPs solution and 3 min. reaction resulting a linear measurement of Hg^{2+} in the range of 0-15 mg/L with LOD and LOQ of 0.039 and 0.130 mg/L respectively. This method is quite selective and has been validated by applying to real face cream samples with satisfactory results supported by average recoveries of close 100 %. Keywords: Mercury, Green Synthesis, Silver Nanoparticles, Coffee Fruit Skin, Spectrophotometry Share Link | Plain Format | Corresponding Author (MUHAMMAD MASHURI UTAMA)

3	Analytical Chemistry	ABS-42
Silver Nanoparticles-mediated Paper-Based Analytical Devices for Detection of Creatinine in Urine Samples Noval D. Wijaya,1) Anita Aprillianti,1) Ulfa Andayani,1) Qonitah Fardiyah,1) Setyawan P. Sakti,2) Ika O. Wulandari,1) Yudit Oktanella,3) Aulanni^am,1) Shova A. Hardiyanti,1) Akhmad Sabarudin1, a) 1)Department of Chemistry, Faculty of Science, Brawijaya University, Jl Veteran, Malang 65145 Indonesia 2)Department of Physics, Faculty of Science, Brawijaya University, Jl Veteran, Malang 65145 Indonesia 3)Department of Animal Reproduction, Faculty of Veterinary Medicine, Brawijaya University, Jl Veteran, Malang 65145 Indonesia Abstract In this work, we develop inexpensive, disposable, and easy-to-use diagnostic devices for the early detection of creatinine in urine samples using distance-based microfluidic paper-based analytical devices (d-uPADs). Creatinine is detected by the modified Jaffe reaction principle by employing silver nanoparticles (AgNPs)-capped alkaline picrate as a sensing reagent. The alkaline picrate reacts with creatinine, resulting in a color change from yellow to orange. The presence of AgNPs in the alkaline-picrate increases the sensitivity of the proposed method through the formation of orange aggregates of AgNPs-capped alkaline picrate with creatinine, enabling sharper color change easily recognized by the naked eye. The proposed method is successfully applied to urine samples with excellent precision (RSD: 1.18%) and accuracy (97.46-99.97%). Additionally, the proposed method allows a self-standing analysis system to perform an analytical assay, which includes sample introduction, reagent, reaction channel, and detection system. Keywords: creatinine, kidney disease, silver nanoparticles, paper-based devices, Jaffe reaction Share Link | Plain Format | Corresponding Author (Noval Dwi Wijaya)

4	Analytical Chemistry	ABS-43
Detection of Albumin Using Gold Nanoparticles-mediated Microfluidic Paper-based Analytical Devices Shova A. Hardiyanti,1) Noval D. Wijaya,1) Lusi Krisdiyanti,1) Salsabillah F. A. Putri,1) Hermin Sulistyarti,1) Ani Mulyasuryani,1) Setyawan P. Sakti,2) Aulanni^am,1) Akhmad Sabarudin,1, a) 1)Department of Chemistry, Faculty of Science, Brawijaya University, Malang 65145, Indonesia. 2)Department of Physics, Faculty of Science, Brawijaya University, Malang 65145, Indonesia. Abstract In this work, we develop the rapid diagnostic kit potentially applied as point-of-care testing for kidney disease (nephropathy) through the detection of albumin in urine samples. For this purpose, gold-nanoparticle (AuNPs) in combination with anionic dyes of Bromocresol Purple (BCP) and Bromothymol Blue (BTB), which are immobilized onto distance-based microfluidic paper-based analytical devices (d-uPADs), are utilized as sensing reagents. In this device, two mechanisms operate for quantitative and semiquantitative detection of albumin using d-uPAD, which includes (1) protein error of pH indicator by direct reaction of albumin with dyes, and (2) full corona protein formation of AuNPs with albumin. These synergistic reaction mechanisms facilitate the sharp color change of dyes, which are easily detected by the naked eye. Some parameters affecting the sensitivity of the proposed method, such as dyes concentration, pH, reagent volume ratio, reagent immobilization, and reaction time are investigated in detail. Inexpensive, disposable, and easy-to-use without technical expertise for albumin detection are advantages of the proposed method. Additionally, the proposed method has high precision (RSD: 1.08-1.37%) and accuracy (95.74-99.96%). Keywords: Albumin, Kidney disease, Paper-based devices, Gold Nanoparticles, Anionic dyes Share Link | Plain Format | Corresponding Author (Shova Audinia Hardiyanti)

5	Analytical Chemistry	ABS-44
Preparation of Microbore Polymer-based Monolithic Columns as Chiral Stationary Phases for Liquid Chromatography Akhmad Sabarudin, Suci Amalia, Stevin C Angga, Bhisma W Khabibi Department of Chemistry, Faculty of Science, Brawijaya University, Jl Veteran 65145, Malang, Indonesia. Abstract Enantiomer molecules have different structure conformations which exhibit different beneficial biological activities as well as pharmacological effects. Separation of enantiomers requires great effort since ordinary chromatographic separation could not distinguish these molecules. In this work, poly-(glycidyl methacrylate-co-ethylene glycol dimethacrylate) (poly-(GMA-co-EDMA)) and poly-(glycidyl methacrylate-co-trimethylolpropane trimethacrylate) (poly-(GMA-co-TRIM)) columns were prepared by in-situ copolymerization inside a PEEK tubing using porogens of 1-propanol, 1,4-butanediol and water at appropriate ratio in the presence of AIBN as a radical initiator (1% of the total monomer). These monoliths were modified with ethylenediamine-beta-cyclodextrin (EDA-B-CD) for separation of chiral compounds. Additionally, metal-mediated monolithic molecularly imprinted polymers (MIPs) columns were prepared using the ionic liquid of [BMIM]BF4 as the main pore-forming agent, and transition metal ions as the pivots, whereas an (R)-(+)-citronellal or an (R)-(+)-pulegone was used as a template, and 4-vinylpyridine and EDMA or TRIM as a cross-linker. Keywords: Chiral Separation, Polymer, Monolith, Chromatography, Metal pivot Share Link | Plain Format | Corresponding Author (Akhmad Sabarudin)

6	Analytical Chemistry	ABS-55
Analysis of Trigonelline Compounds in Coffee using Temperature Programmable Inlet (TPI) in GC-MS Lisa Nurwidya M. Sakaria, Setya Ayu Aprilia, Neena Zakia, Surjani Wonorahardjo Departement of Chemistry, Faculty of Mathematics and Natural Science, State University of Malang Abstract Coffee contains many chemical compounds which are useful for health. Trigonelline is a non-volatile compound that can be identified using LC-MS and HPLC methods after some steps of sample preparation. In this study, trigonelline analysis was carried out by developing a programmable inlet temperature in GC-MS using various injection temperatures. Some components might have been the result of trigonelline decomposition into smaller molecules which determine the coffee flavors. The coffee sample used was Arabica Lemar coffee from the Wonosantri Abadi plantation, Malang, Indonesia. The research includes grinding and solvent extraction before different temperatures for injection into the chromatography column. The results showed that at higher injection temperatures, the presence of some chemicals or pyridine derivative compounds was detected. The profiles were different from one to other roasting temperatures or injection temperatures. More investigation would be done to follow the changes in chemical components due to temperature, in which the presence of other components would also be acknowledged. In natural products all components^ presence count in bringing the properties together in a unique way. Keywords: Trigonelline, GC-MS, Injection Temperature Share Link | Plain Format | Corresponding Author (Lisa Nurwidya M. Sakaria)

7	Analytical Chemistry	ABS-61
Cross-Bound Carboxymethyl Kappa-Carrageenan Coated Nanomagnetite as Cobalt(II) Adsorbent Arina Ulfa Elyanora, Irma Kartika K, Neena Zakia, Hanumi Oktiyani R, Anugrah Ricky W, Surjani Wonorahardjo Universitas Negeri Malang Abstract This study developed an adsorbent for cobalt(II) ions, in the form of nanomagnetite coated with carboxymethyl kappa-carrageenan cross-linked Bisphenol A Diglycidyl Ether (BADGE) with a magnetite solid phase extraction technique (Magnetic Solid Phase Extraction, MSPE). This adsorbent consists of nanomagnetite as a core and a functional layer on its surface. The purpose of this study was to synthesize nanomagnetite coated with carboxymethyl kappa-carrageenan (CMKC) crosslinked with BADGE, as an adsorbent of Co(II) ions and to test its ability in repeated use. The stages of this research are, the first stage is the synthesis of nanomagnetite and its characterization using SEM, FTIR, and XRD instruments, the second stage is the synthesis of CMKC and its characterization using the FTIR instrument, the third stage is the synthesis of crosslinked CMKC coated nanomagnetite BADGE, The synthesis results were characterized using FTIR and SEM instruments. The fourth stage of the adsorbent was tested for its adsorption ability on water samples containing Co(II) ions. The CMKC coated nanomagnetite crosslinked with BADGE which has been successfully synthesized has a rough, porous, and pleated adsorbent surface. The FTIR spectrum of the adsorbent showed a shift in the C=O asymmetric vibration peak from 1634 cm-1 to 1646 cm-1 after crosslinking. The adsorption ability test of BADGE cross-linked CMKC-coated nanomagnetite adsorbent on water samples containing Co(II) ions showed an adsorption capacity of 3.1 mg Co(II)/gram adsorbent. The repeated use of the cross-linked CMKC coated nanomagnetite adsorbent decreased the adsorption capacity by 24% from the adsorption capacity in the first use, which was 86%. Keywords: Nanomagnetite, CMKC, crosslinking, BADGE, Cobalt(II) Share Link | Plain Format | Corresponding Author (ARINA ULFA ELYANORA)

8	Analytical Chemistry	ABS-69
Development of Hydrazine Sensor Based on Modified Glassy Carbon Electrode Hemas Arif Rahman1, Wulan Tri Wahyuni1,2, Budi Riza Putra3* 1 Analytical Chemistry Division, Department of Chemistry, Faculty of Mathematics and Natural Sciences, Kampus IPB Dramaga, Bogor 16680, Indonesia 2 Tropical Biopharmaca Research Center, Institute of Research and Community Empowerment, IPB University, Bogor 16680, Indonesia 3 Research Center for Metallurgy, National Research and Innovation Agency (BRIN) Republic of Indonesia, Jakarta, Indonesia * Corresponding author, e-mail: budi.riza.putra[at]brin.go.id Abstract Hydrazine is a toxic compound which has neurotoxin, mutagenic, carcinogenic, and hepatotoxic properties. In this work, a glassy carbon electrode or GCE has been modified with the composite of electrochemically reduced graphene oxide or ErGO and poly 3,4 ethylenedioxythiophene polystyrenesulfonate or PEDOTPSS for the purpose of hydrazine detection. The proposed sensor exhibits a well electrochemical and analytical performance investigated with the optimum parameters for the measurement using cyclic voltammetry or CV, differential pulse voltammetry or DPV, and square wave voltammetry or SWV techniques. In particular DPV and SWV techniques displayed a linear relationship in the concentration range of 100 to 200 uM of hydrazine based on GCE modified ErGO/PEDOT:PSS. Furthermore, both techniques were used to obtain the value the detection limit (LoD) and quantitation limit (LoQ) for hydrazine detection as 10 uM and 50 uM for DPV and 15 uM and 60 uM for SWV. In addition, this proposed hydrazine sensor displayed a good selectivity due to its recovery range in the range 95 to 120 percent with an acceptable reproducibility and stability indicated by % RSD value of less than 5 percent. In conclusion, this proposed sensor for hydrazine detection based on GCE modified ErGO/PEDOT:PSS shows a potency to be applied in real analysis. Keywords: electrochemically reduced graphene oxide, hydrazine, PEDOT:PSS, voltammetry, water analysis Share Link | Plain Format | Corresponding Author (Budi Riza Putra)

9	Analytical Chemistry	ABS-73
The Analysis of Catechin and Caffeine in Green Tea Capsule and Teabag Using High-Performance Liquid Chromatography Amirah Najihah Mohd Affandi, Nursyamsyila Mat Hadzir, Hairul Amani Abdul Hamid, Noraini Hamzah and Wan Nazihah Wan Ibrahim School of Chemistry and Environment, Faculty of Applied Sciences, Universiti Teknologi MARA, 40450, Shah Alam, Selangor, Malaysia Abstract Green tea leaves contain antioxidants such as catechin and caffeine, which can speed up metabolism, and helps break down excess fat, respectively. However, there are concerns that overconsumption of catechin and caffeine could cause severe effects on the liver of the consumers and kidney failure, respectively. This study involved the quantitative analysis of catechin and caffeine in three different brands of green tea teabag and two different brands of green tea capsule using High-Performance Liquid Chromatography (HPLC). All standards were extracted using methanol, then dissolved in the mobile phase of deionized water and acetonitrile (30:70 v/v), analysed at a wavelength of 270 nm in triplicates using the HPLC-DAD system. The data interpretation was conducted using standard calibration plot and the correlation coefficient for catechin and caffeine was 0.9823 and 0.9856, respectively. Teabag samples were labelled A, B, and C, while capsules samples were labelled D and E. The highest amount of catechin (7274.2679 mg) and caffeine (2253.8581 mg) was found in Sample E. In Sample D, only 1.1561 mg of caffeine was detected and no catechin was detected which probably due to high level of detection (LOD) and quantification (LOQ). The analysis of catechin and caffeine using HPLC was proven to be reliable, simple, sensitive, and rapid. Keywords: Caffeine, Catechin, HPLC Share Link | Plain Format | Corresponding Author (NURSYAMSYILA MAT HADZIR)

10	Analytical Chemistry	ABS-76
Bulk and Precipitation Polymerization Techniques in Alpha Mangostin Imprinted Polymers Synthesis Neena Zakia 1, Muhammad A. Zulfikar 2 and Muhammad B. Amran 2 1 Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Negeri Malang, Jalan Semarang 5, Malang, East Java 65145, Indonesia 2 Division of Analytical Chemistry, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jalan Ganesa 10, Bandung, West Java 40132, Indonesia Abstract Alpha mangostin is a xanthone compound in the mangosteen rind, which has pharmacological activities such as antioxidant, anticancer, and antiinflammatory. There are many xanthone derivatives in the mangosteen rind, but each compound has different benefits. An effort is needed to obtain alpha mangostin compounds selectively. The use of a molecular imprinted polymers material as a sorbent is able to effectively separate the target compound from a sample with a complex matrix. The aim of the research was to synthesize imprinted polymers with alpha mangostin as a molecule template by bulk and precipitation techniques. In this study the synthesis of alpha mangostin imprinted polymers using methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as a crosslinker, benzoyl peroxide as an initiator, and acetonitrile as a porogen. The volume of porogen used in the bulk technique is 10 mL and the precipitation technique is 20 mL. As a comparison, a control polymer was synthesized using the same procedure, but without the presence of a template molecule. Physical characterization by FTIR and SEM, and retention characterization included adsorption capacity and imprinting factor (IF). The results obtained indicate that the synthesis of molecular imprinted polymers has been successfully carried out using bulk and precipitation techniques. The adsorption capacity of the bulk technique is 11.214 mg.g-1 and the IF value is 1.78, while the adsorption capacity of the precipitation technique is 11.767 mg.g-1 and the IF value is 2.87. Keywords: alpha mangostin- molecular imprinted polymers- bulk polymerization- precipitation polymerization Share Link | Plain Format | Corresponding Author (Neena Zakia)

11	Analytical Chemistry	ABS-77
Incorporation of Green Curriculum and Green Chemistry Concepts in Chemistry Lab Practice and Waste Treatment Soerjani Widyastuti, Nur Yusrina, Sasti Gona Fadhilah, Mohammad Misbah Khunur Department of Chemistry, Brawijaya University, Malang. Abstract This study reports the incorporation of both green curriculum and green chemistry concepts in the design of educational chemistry practicum and in the in-situ laboratory waste treatment. Fundamental Chemistry Practicum subject at the Faculty of Mathematics and Natural Sciences, Brawijaya University (2019-2020) was used as the research object. First, the existing practicum module was evaluated and modified, in term of use of chemicals and student learning outcomes. Next, the new module was implemented into the real practicum (two semesters). The collected liquid waste was then treated using left-over chemicals from the practicum by neutralisation-precipitation methods. Concentration of selected metal ions (Ca, Fe, Cu, Pb) before and after treatments was analysed by atomic absorption spectroscopy, whereas solid waste precipitated out from the treatments was analysed by infrared spectroscopy. The result shows that those concepts can reduce the volume and toxicity of laboratory liquid waste significantly, maximise the use of chemicals, both for the practicum and the liquid waste treatment, which at the same time, maintain the student learning outcomes achievement. In particular, use of simple tools and chemicals, and plenty of choice of chemicals and experimental models in the Fundamental Chemistry Practicum subject are the main reasons for the high feasibility of applying this concept. However, each laboratory and practicum has its own requirement, thus application of this concept for other types of chemical laboratory or chemistry practicum may shows different results. Keywords: green curriculum, green chemistry, liquid waste, waste treatment, laboratory practice. Share Link | Plain Format | Corresponding Author (Mohammad Misbah Khunur)

12	Analytical Chemistry	ABS-84
The effect of Al (III) Chrysin Complex Reagent Composition on Determination of Fluoride Ion Spectrophotometry Qonitah Fardiyah, Barlah Rumhayati, Anisah Nabila Azzah Chemistry Department, Faculty of Mathematic and Natural Science Brawijaya University, Indonesia Abstract Fluoride ion in water could be determined with metal flavonoid complexes such as Alumunium and ,7-dihydroxy-flavone (chrysin)complex. In this research, the optimum composition of the Al-chrsyin complex reagent on determination of fluoride ion spectrophotometry was studied. The complex reagent used ethanol as the solvent. This method relied onto the reaction of yellow coloured metal-chrysin complex with fluoride ions which resulted in colourless complex. The reaction corresponded with the concentration of fluoride in water. AlCl3 and Al(NO3)3 were used as the metal in the metal-chysin complex. The stoichiometry of the complex was investigated using Job^s method with continuous variation. Both aluminium variations resulted with 1:3 complex. The equilibrium time of Al(III)-Chrysin complex reagents were determined by simple procedure using UV-Vis spectrophotometry with 371 nm as maximum wavelength. The result shows that the Al(NO3)3-Chrysin complex reagent obtained 155 minute and 175 minutes for the AlCl3-Chrysin complex reagent respectfully. The limit of detection, limit of quantification and correlation coefficient for the determination of fluoride in water with Al(NO3)3-chrysin complex were found to be 1,25 ppm- 3,77 ppm- and 0,999. Keywords: fluoride, chrysin, metal, ligand, UV Vis spectrophotometry Share Link | Plain Format | Corresponding Author (Qonitah Fardiyah)

13	Analytical Chemistry	ABS-89
OPTIMUM TEMPERATURE MEASUREMENT TO IDENTIFY BANYUWANGI COFFEE AROMA PROFILE USING ELECTRONIC NOSE INSTRUMENT Zulfikar,1, a) Tri Mulyono,1) Dhea Melynia Putri Nur Darmala,2,b) Siswoyo,1) Asnawati1) and Yeni Maulidah Muflihah1) 1) Department of Chemistry, Faculty of Mathemathics and Natural Sciences, Universitas Jember, Jl Kalimantan 37, Jember, 68121, Indonesia 2) Student of Department of Chemistry, Faculty of Mathemathics and Natural Sciences, Universitas Jember, Jl Kalimantan 37, Jember, 68121, Indonesia Abstract Coffee is one of the leading plantation commodities in Indonesia. Coffee production in Indonesia is dominated by the type of robusta coffee, which reaches 80% of the total national coffee production. Banyuwangi is one of the largest coffee-producing districts in East Java where in 2021 the total coffee production in Banyuwangi will reach 10,518 tons. Coffee plantations located in Banyuwangi Regency include Glenevis, Malangsari, Kalipuro and Kalibendo gardens. The characteristics of coffee from each garden have their own characteristics, both in terms of taste and aroma due to the different components of the constituent compounds. Identification of coffee aroma characteristics can be done in several ways, one of which is using an electronic nose instrument. This instrument consists of a series of gas sensors arranged in an array position and connected to Arduino as the resulting signal processor system. The working principle of the electronic nose instrument is similar to the performance of the human sense of smell system. In this case, the sensor detects the aroma that comes from the coffee vapor so that it produces a voltage response from the sensor. The response will then be forwarded to the Arduino to convert the analog signal into a digital signal that can be displayed on the monitor. This research uses eight types of gas sensors, namely MQ2.MQ3, MQ6, MQ7, MQ8, MQ9, MQ135, and MQ136 sensors. Research on the identification of coffee aromas using an electronic nose has been done a lot before, so it is necessary to do some optimizations to improve the performance of the coffee electronic nose in detecting the response pattern of coffee aroma. This study aims to determine the optimum temperature measurement used in the identification process of coffee aroma profile using a gas array sensor arranged in a planar shaped chamber. Determination of the optimum temperature is intended so that later the maximum measurement results can be obtained so that the system electron Keywords: Banyuwangi Coffee, Electronic Nose, Temperature Measurement, Principal Component Analysis Share Link | Plain Format | Corresponding Author (Dhea Melynia Putri Nur Darmala)

14	Analytical Chemistry	ABS-90
The Effect Of Fe3O4/SiO2/CaCO3 Nanocomposites As Ammonia Analysis In Wastewater Of Shrimp Pond In Prigi Bay Using Nessler Method Lukluatus Syavika, Anugrah Ricky Wijaya*, and Alif Alfarisyi Syah Department of Chemistry, Faculty of Mathematics and Science, State University of Malang Jl. Semarang no.5, Indonesia *Corresponding author: anugrah.ricky.fmipa[at]um.ac.id Abstract Abstract. Ammonia contained in shrimp pond wastewater will harm the surrounding environment if the waste is disposed of freely without prior treatment. The adsorbent is used to reduce the concentration of ammonia in shrimp pond waste. This study used CaCO3 to coat Fe3O4/SiO2 nanocomposites. CaCO3 is used as a coating for nanocomposites because it has been investigated to be able to be used as an adsorbent to reduce ammonia from a liquid sample. Synthesis of Fe3O4/SiO2/CaCO3 nanocomposite using coprecipitation method. Characterization of Fe3O4 nanoparticles, and Fe3O4/SiO2/CaCO3 nanocomposites using FT-IR and XRD. The synthesis was successful but the adsorbent did not adsorb ammonia. CaCO3 and SiO2 solids can adsorb ammonia, while Fe3O4 nanoparticles desorb ammonia. Solid SiO2 has a higher % adsorption than CaCO3 in standar solution but in sampel of shrimp pond wastewater 0.1 grams of CaCO3 was able to reduce ammonia levels in shrimp pond wastewater by 0.9907 mg/L with % adsorption was 10.02% and better than adsorption of solid SiO2. Keywords: nanocomposite, Fe3O4/SiO2/CaCO3, ammonia, Nessler, Prigi Share Link | Plain Format | Corresponding Author (Lukluatus Syavika)

15	Analytical Chemistry	ABS-92
Synthesis and Development of Fe3O4/SiO2/C Nanocomposite as NH4+ Ion Adsorbent from Shrimp Pond Output Water Using Phenate Method Alif Alfarisyi Syah1 , Anugrah Ricky Wijaya1* , and Lukluatus Syavika1 Department of Chemistry, Faculty of Mathematics and Natural Sciences, State University of Malang, Jl. Semarang 5 Malang 65145, Indonesia *Corresponding author: anugrah.ricky.fmipa[at]um.ac.id Abstract Abstract. The high ammonium content in the aquatic environment originating from the output water of shrimp ponds has a negative impact if in high concentrations it has the potential to cause disturbance and pollution in aquatic ecosystems. To reduce the ammonium content, we use nano adsorbent. Furthermore, the synthesis of Fe3O4/SiO2/C nanocomposite as an ammonium ion adsorbent was carried out. Nanocomposites were synthesized by the coprecipitation method. Carbon was synthesized from polyethylene terephthalate (PET) plastic waste to coat Fe3O4/SiO2 nanocomposites. The availability of PET is very abundant, the carbon content is high, the impurities are low, the cost is cheap, and the activated carbon produced has a large surface area so that it has maximum potential in the ammonium ion adsorption process. Carbon activation was carried out by the chemical activation method and KOH as an activator reagent because it can produce activated carbon with a large surface area, adsorption capacity, mesoporous volume, and total pore volume. Characterization of Fe3O4 nanoparticles, carbon, and Fe3O4/SiO2/C nanocomposites using XRD, FT-IR, VSM, SEM-EDX, BET instruments and for analysis of ammonium ion content after adsorption using the phenate method Keywords: Ammonium, Fe3O4/SiO2/C, nanocomposite, adsorbent, Carbon Share Link | Plain Format | Corresponding Author (Alif Alfarisyi Syah)

16	Analytical Chemistry	ABS-97
Development and Application of Co-C Electrodes for Potentiometric Determination of Phosphate Ion in Agricultural Soils Compared to Spectrophotometric Method Siswoyo, Lia Indah Wardiyani, and Yudi Aris Sulistiyo Department of Chemistry, Faculty of Mathematics and Natural Science, Universitas Jember, Jl. Kalimantan 37 Jember 68121, Indonesia. Abstract Phosphorus is a nutrient in the soil that is used by plants to grow, so its presence needs to be known as basic information in land management. Phosphorus content analysis is usually carried out by measuring phosphate ions extracted from soil samples using spectrophotometric methods. This paper reports the results of the development of an alternative phosphate measurement method through the design of a cobalt-based potentiometric electrode capable of selectively detecting phosphate ions. The electrodes were made voltammetrically to reduce the cobalt ions in solution and attach them to the ends of the carbon rods. The cobalt thin layer on the carbon tip is an active part of the Co-C electrode in the process of potentiometric detection of phosphate ions. The results of the characterization of the electrode performance on the measurement of a series of standard phosphate solutions showed that this electrode had a sensitivity value of 28.01 mV/decade. Meanwhile, the selectivity coefficient for interfering ions (NO3-, NH4+, K+ and Cl-) is <1 which indicates that the interference of these ions does not significantly affect the measurement of the main ion. The electrode also has good precision by showing the value of variation coefficient < 5%. Compared with the spectrometric method in the measurement of agricultural soil samples at four locations, it was shown that the Co-C electrodes showed equivalent results, as evidenced by the correlation coefficient of 0.998. It can be stated that the Co-C electrode is very promising to be used as an alternative method of measuring phosphate. Keywords: soil phosphate, Co-C electrode, potentiometric method, spectrophotometric method, soil sample analysis Share Link | Plain Format | Corresponding Author (Siswoyo Siswoyo)

17	Analytical Chemistry	ABS-103
The effect of bisulphite salt on traditional coconut sugar production Ellya Indahyanti (1a), Bambang Ismuyanto(2), Budi Kamulyan(1) (1) Chemistry Deparment, Brawijaya University (2) Chemical Engineering Deparment, Brawijaya University Abstract Bisulphite salt sometimes added into foods as a preservative agent. It was added into coconut sap and reproduced coconut sugar. Coconut sap quality is based on its pH, reducing sugar and sucrose content, while coconut sugar is not only depend on its reducing sugar, sucrose and water content but also the bisulphite residual. The Lane-Eynon volumetric method was used to determine sugar content, and gravimetry for water content. Volumetric method was also used to measure bisulphite residual. Addition of bisulphite salt could inhibit the development of microbes saccaromyces cereviciae in coconut sap. Some of the disaccharide sugars undergo hydrolysis into glucose and fructose, and continue to fermentation process to form acetic acid and several other organic acids. Keywords: Bisulphit salt, reducing sugar, coconut sap Share Link | Plain Format | Corresponding Author (Ellya Indahyanti)

18	Analytical Chemistry	ABS-105
The effect of Crosslinking Temperature on the Swelling Degree of Citric Acid-Agarose Gel for Diffusive layer of DGT Digwanggi Arum Tazkiyatu An-Nufuus, Barlah Rumhayati, Qonita Fardiyah, Diah Mardiana, Ulfa Andayani, Layta Dinira Department of chemistry Faculty of mathematics and natural sciences Brawijaya University Abstract Diffusive gradient in thin films (DGT) technique is a diffusive passive sampling technique which is combined in situ analyte uptake, contaminants filtration, and pre concentration in a single way. Probe of DGT consists of a filter, diffusive layer, and a binding layer sequentially. Agarose has been used for the diffusive layer of DGT with big pore size inducing high swelling degree. Addition of crosslinker, such as citric acid, for agarose-diffusive layer can reduce the swelling degree. The aim of this research was to study the effect of temperature of crosslinking of citric acid and agarose on the swelling degree of the diffusive gel. Agarose diffusive layer was prepared by mixing 1.5% agarose solution with the addition of 0.75% citric acid solution. The mixture was casted in an oven at temperature of 25, 40, 50, 70 Celsius degree. The formed gel then was soaked in water, NaCl 0.1 M, pH 4, 5, 6, 7, and 8 for 1, 2, 3 and 24 hours. The mass of gel was weighted before and after soaking. Swelling degree is the ratio between the final mass and the initial mass. Results shows that the swelling degree of agarose-citric acid diffusive gel was stable at 3 hours. The diffusive layer showed stable swelling degree at crosslinking temperature of 400 C. The diffusive layer was not swelling out in the media of NaCl 0.1 M. Keywords: citric acid, diffusive layer, agarose, DGT, swelling Share Link | Plain Format | Corresponding Author (Barlah Rumhayati)

19	Analytical Chemistry	ABS-122
Ion Imprinted Polymer for Chromium(VI) Adsorption in Tannery Waste Water Alya Amalia, M. Bachri Amran Bandung Institute of Technology Abstract This research aims to perform the adsorption of chromium(VI) ions in the liquid waste of the leather tanning industry using ion imprinted polymers. Ion Imprinted Polymers (IIP) were developed on the same principle as the lock and key mechanism for recognizing and removing ions. In this research, synthesis of chromium(VI) ion imprinted polymer which is selective for chromium(VI) ion in leather tanning industry waste samples was carried out. IIP preparation was carried out using Cr(VI) ion, 1,5-diphenyl carbazide as a complexing agent, methacrylic acid as a monomer, EGDMA as a crosslinker and benzoyl peroxide as an initiator. Determination of the optimum conditions for IIP adsorption which include: pH, contact time, and mass of adsorbent. The optimum conditions for Cr(VI) adsorption were obtained at pH 3, with a contact time of 240 minutes, and a Cr(VI)-IP mass of 50 mg. The characterization of the obtained IIP was analyzed using the FTIR instrument, which showed a typical spectrum at 1261.45 dan 472.56 cm-1. The adsorption isotherm model obtained is following the Freundlich isotherm model, where based on the value of 1/n, the adsorption of Cr(VI) by Cr(VI)-IP shows that the adsorbent surface is heterogeneous, with the R2 value of the Freundlich isotherm 0.9876. The adsorption kinetics model follows the pseudo-second-order kinetics model. The synthesized Cr(VI)-IP are selective against other metal ions by having a value of K^ (relative selective coefficient > 1 for Cr3+ and Cd2+ ions. Adsorption-desorption test gives a % Recovery of 87.15%. Analysis of Cr(VI) in leather tanning industry have a % Recovery of 70.06%. Keywords: ion imprinted polymer, chromium, leather tanning industry Share Link | Plain Format | Corresponding Author (Alya Amalia)

20	Analytical Chemistry	ABS-123
ANALYSIS OF MANGROVE PLANT AS BIOCHAR FOR ADSORPTION OF Ni2+ ION Anugrah Ricky Wijaya*, Resi Destiani, Salsabila Inas Pramila, Puspa Rahmadina Lestari, Alif Alfarisyi Syah, Lukluatus Syavika, Hanumi Oktiyani Rusdi, Neena Zakia Department of Chemistry, Faculty of Mathematics and Science, State University of Malang Jl. Semarang no.5, Indonesia Corresponding author: anugrah.ricky.fmipa[at]um.ac.id Abstract Abstract. Mangrove plant around Prigi beach has the potential to be used as biochar adsorbent to remove nickel content. The high Ni concentrations can cause water pollution problems, which is needed as adsorbent at this time. This study aims to characterize mangrove biochar using XRF, SEM, and FT-IR and determine the optimization of the size and contact time of mangrove biochar on the nickel ion in the adsorption process. The leaves, seeds and mangrove stems were collected and produced biochar using the pyrolysis method, and then characterized with XRF, FT-IR and SEM. The results of this XRF analysis of mangrove plants contained a content of 0.01% NiO. The FT-IR results show the presence of the main functional group O-H at a wave number of 3319.49 cm-1, and SEM magnification of 2500x found that biochar has a rough morphology and the presence of micropores with an average particle diameter of 2018 m. The adsorption test showed that the adsorbent in bulk size was able to absorb the highest nickel metal ion of 99.4% with a contact time of 48 hours. Keywords: Mangrove, Biochar, Prigi Bay, Adsorption, Nickel Share Link | Plain Format | Corresponding Author (Anugrah Ricky Wijaya)

21	Analytical Chemistry	ABS-125
Investigation and Mapping of Level Ammonia in The Shrimp Pond Sludge Sediments of Prigi Bay Anugrah Ricky Wijaya*, Dera Putri Rahmadarti, Alif Alfarisyi Syah, Lukluatus Syavika, Irma Kartika Kusumaningrum, Eli Hendrik Sanjaya, Yudhi Utomo, Aman Santoso, and Muntholib Department of Chemistry, Faculty of Mathematics and Science, State University of Malang Jl. Semarang no.5, Indonesia Corresponding author: anugrah.ricky.fmipa[at]um.ac.id Abstract Abstract. Shrimp farming in Prigi Bay adjacent the seawater produces ammonia organic waste which has the potential to cause marine pollution. To identify and map the ammonia content of shrimp ponds around the sea, we investigated the ammonia content in sludge sediment. Identification of ammonia in sediments were used and applied the Phenate and Nessler methods, respectively and then mapped using Arcgis software. Ammonia phenate identification was chosen as a method with good linearity (r = 0.999), which is higher than the Nessler method (r = 0.994). The results of accuracy and precision in this method reached ~100% of recovery and 1.23% of RSD. This method is very suitable for mapping ammonia as a marine pollution. The results of the shrimp pond ammonia levels showed from 2.899 to 23.270 mg/L. The results of the analysis of shrimp pond waste sediment exceeds the quality standard of ammonia which has the potential to pollute the sea. Mapping of the potential for ammonia pollution is clearly divided into several polluted zones, indicating alarm pollution in the seawater. Keywords: Shrimp pond sediment, ammonia, Fenat Method, Nessler Method Share Link | Plain Format | Corresponding Author (Anugrah Ricky Wijaya)

22	Analytical Chemistry	ABS-130
Analysis of Packed Drinking Water by Physical and Chemical Parameters Desmilia Putri Ramadhani1,a), Eka Bella Corisa1,b), Hanumi Oktiyani Rusdi1,c), Melastri Rahayu2) 1) Departement of Chemistry, Faculty Mathematics and Natural Sciences, Universitas Negeri Malang, Jalan Semarang No. 5, Malang, East Java, Indonesia 2) PT Tirtamas Lestari, Jalan Raya Sumberingin No. 67, Sumbersuko, Gempol, Pasuruan, East Java, Indonesia Corresponding author: c)hanumi.rusdi.fmipa[at]um.ac.id a)desmilia.putri.1903326[at]students.um.ac.id b) eka.bella.1903326[at]students.um.ac.id, Abstract Packed drinking water is a product consumed by all levels of society and has become part of the necessities of life. This study aims to analyze the quality of packed water from four products on the market in terms of physical and chemical parameters based on the Indonesian National Standard (SNI). Physical parameters are organoleptic tests, total dissolved oxygen (TDS), and conductivity. The results of the physical parameter test show that drinking water has a clear, tasteless, smelly color with total dissolved oxygen (TDS) of 127.9 - 138.2 NTU and a conductivity of 256 - 277. Chemical parameters are pH testing, ozone levels, and hardness. Chemical parameter test results show that drinking water has a pH of 6.98 - 8.85, an ozone level of 0.09-0.3 mg/L, and a hardness of 101.067 and 106.02. Overall, the test results show that the quality of packed drinking water meets Indonesian national standards. Keywords: drinking water, TDS, conductivity, pH, ozone levels, hardness Share Link | Plain Format | Corresponding Author (Hanumi Oktiyani Rusdi)

23	Analytical Chemistry	ABS-131
Validation of Flow Injection Analysis Method for Anionic Surfactant Analysis Hanumi Oktiyani Rusdi1,a), M. Bachri Amran2) 1) Departement of Chemistry, Faculty Mathematics and Natural Sciences, Universitas Negeri Malang Jl. Semarang No. 5, Malang, East Java, Indonesia 2) Departement of Chemistry, Faculty Mathematics and Natural Sciences, Universitas Negeri Malang Jl. Ganesha No. 10, Bandung, West Java, Indonesia Corresponding author: a)hanumi.rusdi.fmipa[at]um.ac.id Abstract A method has been developed to analyze anionic surfactants (Sodium Dodecyl Sulfate/SDS) based on the formation of ion pairs of anionic surfactants with cationic dyes (Brilliant Green/BG) preconcentrated using a C18 mini-column. This ion pair was then eluted with an organic solvent such as methanol-chloroform (1:9) as much as 1 mL. Measurements were made using visible light spectrometry at a wavelength of 629 nm. The analytical performance of the developed method provides a precision value of 2.17%, a detection limit of 9.62 ppm, and a sensitivity of 2.2 ppm. Linearity determined through the calibration curve obtained the equation y = 0.002x + 0.009 (R2 = 0.987) with a percent recovery of 82%. The FIA &#8203-&#8203-performance was determined by the enrichment factor value of 35.08, the efficiency of the concentration of 15 h-1 and the consumptive index value of 9.5 mL. From the analysis performance and FIA performance, it can be concluded that this method can be used for surfactant analysis in water samples. The application of the method on river water samples showed surfactant levels of less than 10 ppm. Keywords: anionic surfactant, flow injection analysis Share Link | Plain Format | Corresponding Author (Hanumi Oktiyani Rusdi)

24	Analytical Chemistry	ABS-132
The Effect of Wet Hulling Process of Green Bean Coffee on Chemical Compounds in Arabica Coffee Surjani Wonorahardjo, Fazria Rizqi Maharani, Chariztya Anggita Maharani, Hanumi Oktiyani Rusdi, Suharti Suharti, Yudhi Utomo, Dian Puspita Sarii Oktiyani Rusdi, , Suharti Suharti (1) Chemistry Department State University of Malang Jl. Semarang 5 Malang Indonesia Abstract The hulling process of green bean coffee has been investigated under fermentation. Fermented coffee is called ^honey^ coffee in contrast with ^natural^ coffee, in which no water is added during hulling. The taste and aroma of honey coffee are preferable for some people, which is why the chemical composition is to be investigated. Fermentation allows changes in protein structure in the presence of carbohydrates as well. The changes gave effect to the smaller compounds during roasting degradation. The chemical profiles change along with increased temperatures, giving volatile components responsible for the flavour and typical coffee odour. The chemical compositions were analyzed using gas and liquid chromatography for the volatile and non-volatile components. Caffeine, as the typical compound of coffee, is found less in the amount in fermented coffee beans through conventional UV-vis experiments. The volatile and non-volatile profiles differed from the gas and liquid chromatography-mass spectrometry results. Some intensive investigations of the components are being conducted, especially for more extended chain acid components, including trigonelline and chlorogenic acid. Keywords: coffee, fermentation, GCMS, LCMS Share Link | Plain Format | Corresponding Author (Surjani Wonorahardjo)

25	Biochemistry	ABS-10
In Vitro Alpha-Amylase Inhibitory Activity of Microencapsulated Cosmos caudatus Kunth Extracts Anna Safitri [1, 2]*, Anna Roosdiana [1] [1] Department of Chemistry, Faculty of Mathematic and Natural Sciences, Brawijaya University, Jl. Veteran, Malang, 65145, Indonesia [2] Research Center for Smart Molecules of Natural Genetic Resources (SMONAGENES), Brawijaya University, Jl. Veteran, Malang, 65145, Indonesia Abstract Keywords: chitosan- Cosmos caudatus Kunth- microencapsulation- spray-drying Share Link | Plain Format | Corresponding Author (Anna Safitri)

26	Biochemistry	ABS-11
Hepatitis B Virus HBcAg Gene Transformation in Escherichia coli DH5a Using pEGFP-N1 Dini Cahyani 1) , Lalu Unsunnidhal 2,3) , Tri Untari 4) and Asmarani Kusumawati 5,6) 1 Master Program of Biotechnology, Graduate School of Universitas Gadjah Mada, Jalan Teknika Utara, Kocoran, Caturtunggal, Depok, Sleman, Yogyakarta 55281 Indonesia 2 Food Technology Study Program, Faculty of Food Technology and Agroindustry, University of Mataram, Mataram, 83125, Indonesia 3 Biomedical Field, Nursing Study Program, STIKES Yarsi Mataram, West Nusa Tenggara 83361, Indonesia 4 Departement of Microbiology, Faculty of Veterinary Medicine, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia 5Department of Reproduction and Obstetrics, Faculty of Veterinary Medicine, Universitas Gadjah Mada, Yogyakarta 55281, Indonesia 6Biotechnology Study Program, Graduate School of Universitas Gadjah Mada, Yogyakarta 55281, Indonesia Abstract Hepatitis B virus is a virus that attacks humans and it can cause liver cancer. Hepatitis B subgenotype B3 is commonly found in Southeast Asia. Thus, the development of a vaccine is carried out to prevent the spread of the Hepatitis B virus in Indonesia. The purpose of this study was to transform the hepatitis B virus HBcAg gene using the pEGFP-N1 vector on Escherichia coli DH5a as host cells. The method in this research was codon optimization and plasmid transformation of recombinant DNA in pEGFP-N1. The recombinant cloning was divided into two stages, that was making competent cells and transforming recombinant DNA plasmids. The HBcAg gene was obtained from the results of isolation and cloning that had been carried out by previous researchers, would be constructed on the pEGFP-N1 vector. The results obtained in this study were that the HBcAg gene was successfully cloned and transformed into Escherichia coli DH5a (pEGFP-N1-HBcAg) by heat shock method using MgCl2-CaCl2 reagent. Based on the results of PCR colonies which stated that the transformant bacteria E. coli DH5a succeeded in carrying the pEGFP-N1-HBcAg plasmid marked by the presence of DNA bands with a length of 152 bp. Therefore, the construction of pEGFP-N1-HBcAg using Escherichia coli host cells can be used as a DNA vaccine candidate. Keywords: DNA vaccine, Escherichia coli DH5a, Hepatitis B, pEGFP-N1-HBcAg Share Link | Plain Format | Corresponding Author (Dini Cahyani)

27	Biochemistry	ABS-30
Probiotic properties of Lactobacillus plantarum E2 Isolated from Coffee Fermentation (Wine Coffee) Yoga Dwi Jatmiko, Aryan Mustamin Department of Biology, Faculty of Mathematics and Natural Sciences, Universitas Brawijaya, Veteran Street, Malang 65145, Indonesia Abstract ABSTRACT. Exploration of lactic acid bacteria as probiotics contained in local coffee wine needs to be done. The purpose of this study was to determine the presence of lactic acid bacteria (LAB) isolated from local coffee wine which has potency as a probiotic, and to identify the LAB species with the best probiotic ability from local wine coffee based on 16S rDNA sequences. A total of five samples were taken during coffee fermentation to isolate LAB using MRS agar media added with 1% CaCO3. The characterization of LAB was carried out by Gram staining and catalase test and then continued with the characterization of its probiotic potency. The probiotic characters tested included acid resistance test (pH 2, 3, and 4), bile salt tolerance test (1%, 1.5%, and 2%), antibacterial activity test, sensitivity test to antibiotics and hemolysis activity test. The data obtained were analyzed using ANOVA, and continued with the Tukey test with a significance level of 95%. Lactic acid bacteria from coffee fermentation (wine coffee) have been isolated as many as 25 isolates. Two LAB isolates (D4 and E2) have been selected as probiotic candidates that were able to survive and grow at low pH (pH 2) and in the presence of 2% bile salts with a survival rate of 100%, able to inhibit all tested pathogenic bacteria, and categorized as nonpathogen. Both isolates were resistant to the antibiotics kanamycin and aztreonam. Of the two isolates, isolate E2 was the best isolate in term of probiotic ability, and it was identified as Lactobacillus plantarum with 100% similarity to the MR1 strain. Keywords: lactic acid bacteria, probiotics, coffee wine, fermentation, Lactobacillus plantarum Share Link | Plain Format | Corresponding Author (Yoga Dwi Jatmiko)

28	Biochemistry	ABS-32
Analysis Of Flavonoids And Alkaloids On Stick Based On Cham Flour (Sechium edule) Regita Cahyani and Jamaluddin M, Sakung Tadulako University Abstract Stick is a type of snack that has a long shape and is made of flour dough mixed with other ingredients that is fried and has a savory taste. Sticks are loved by all groups, both children and adults. Sticks made from chayote flour (Sechium edule) are the development of healthy food products that contain flavonoid and alkaloid compounds. This study aims to analyze the levels of flavonoids and alkaloids contained in chayote sticks. Chayote sticks were extracted by maceration method using 96% ethanol solvent and the extract was evaporated with a rotary evaporator at a temperature of 31 degrees Celsius. Analysis of flavonoid and alkaloid content was carried out using UV-Vis spectrophotometer method at a wavelength of 434.5 nm for flavonoid content and a wavelength of 273 nm for alkaloid content. The results of the analysis of the flavonoid content of chayote sticks were 0.335:0.025 g/100g and the alkaloid content analysis was 1.014:0.038 g/100g. The results of this study indicate that sticks made from chayote flour contain flavonoid and alkaloid compounds that are useful for the body so that they can be used as healthy food products that can be developed. Keywords: Chayote sticks, flavonoids, alkaloids, UV-Vis spectrophotometer Share Link | Plain Format | Corresponding Author (Regita Cahyani)

29	Biochemistry	ABS-36
Analysis of Tannins and Saponins in Sticks Made From Chayote Flour (Sechium edule) Nurul Hatifah and Jamaludin M. Sakung Tadulako University Abstract Sticks are snacks consumed by the people. Sticks are a type of food that is made by frying. Sticks made from chayote flour (Sechium edule) are food products that contain tannins and saponins. This study aims to determine the levels of tannins and saponins on sticks made from chayote flour. Sample extraction was carried out by maceration method with 96% ethanol as solvent. The tannin compounds in the sample extracts were analyzed using the UV-Vis Spectrophotometry method, while the saponin compounds in the sample extracts were analyzed using the Gravimetric method. The results showed that the tannin content of the chayote stick was 0.442:0.012 g/100g and the saponin content of the chayote stick was 2.090:0.018 g/100g. So the results of this study indicate that chayote sticks contain tannin and saponin compounds that can be used as snacks that are beneficial to the body. Keywords: Sticks, chayote, tannins, saponins Share Link | Plain Format | Corresponding Author (Nurul Hatifah)

30	Biochemistry	ABS-45
Effect of Additional Red Dragon Fruit Peel and Lemon Peel in The Development of Coconut Water Fermented Beverage Products using Lactic Acid Bacteria to Increase Antibacterial Activity Sofi Nabila, Arie Srihardyastutie, Sasangka Prasetyawan, Aulanniam and Rurini Retnowati Chemistry Departement, Faculty of Mathematics and Natural Science, Brawijaya University, Malang, Indonesia Abstract This study aims to develop a fermented drink with the main ingredient of coconut water which is processed with the addition of mass variants of dragon fruit peel and lemon peel to increase antibacterial activity. Coconut water is one part found inside mature coconuts that contains bioactive compounds that have the potential as antibacterial such as catechin compounds. Catechin compounds are major components is reported to have antimicrobial activities. In this case, the fermentation process using lactic acid bacteria is known to affect the bioaccessibility to degrade catechins to catechol and gallic acid which is supported by the addition of dragon fruit peel and lemon peel to increase antibacterial activity. This research was conducted by fermenting coconut water using commercial lactic acid bacteria and incubating at room temperature. This study method includes 2 stages, namely the length of fermentation (0, 12, 24, 36, 48, and 60 hours) and the addition of mass variant of dragon fruit peel and lemon peel with a ratio (3, 1:2, and 2:1). The optimum condition of the fermentation time is used for the second stage of the fermentation process. In the second stage, determination of total acid, pH, and identification of organic acids was carried out using HPLC. Then, the antibacterial activity was determined using the disc diffusion method. Based on the results showed the optimization of fermentation time that produces the optimum total acid is 48 hours. Product characteristics test showed that the addition of dragon fruit peel and lemon peel gave a significant effect on total acid, pH value and organic acid components. The antibacterial activity from fermented coconut water using lactic acid bacteria starter with 48 hour incubation period against Escherichia coli was higher (inhibitory zones of 4.6 mm) than Staphylococcus aureus (inhibitory zones of 3.24 mm). This study confirmed that the addition of dragon fruit peel and lemon peel can increase antibacterial activity. Keywords: Coconut water, Fermentation, Organic acids, Antibacterial Share Link | Plain Format | Corresponding Author (Sofi Nabila)

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