cover
Contact Name
Armeida Dwi Ridhowati Madjid
Contact Email
armeida@uin-malang.ac.id
Phone
+6281233402334
Journal Mail Official
alchemy@uin-malang.ac.id
Editorial Address
Fakultas Sains dan Teknologi Universitas Islam Negeri (UIN) Maulana Malik Ibrahim Malang Gedung BJ Habibie Lt 2 Jl. Gajayana 50 Malang 65144 Indonesia
Location
Kota malang,
Jawa timur
INDONESIA
Alchemy : Journal of Chemistry
ISSN : 20861710     EISSN : 24606871     DOI : http://dx.doi.org/10.18860/al
ALCHEMY: Journal of Chemistry (eISSN 2460-6871) is a scientific journal that focus on chemistry. This journal publishes a scientific article that cover research and review articles. Research topics for this journal such as natural science, physical chemistry, inorganic chemistry, organic chemistry, environment, biochemistry, marine, energy and other related-sciences. ALCHEMY: Journal of Chemistry also accepts article about halal products and chemistry on Islamic perspectives.
Articles 203 Documents
Uji Aktivitas Antioksidan Ekstrak n-Heksana, Etil Asetat, Metanol Daun dan Akar Bakau Merah (Rhyzophora stylosa) dengan Metode DPPH Hanapi, Ahmad; Fasya, Ahmad Ghanaim; Syakuro, Abdan
ALCHEMY Vol 7, No 1 (2019): ALCHEMY: Journal of Chemistry
Publisher : Department of Chemistry, Faculty of Science and Technology UIN Maulana Malik Ibrahim Malan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (375.14 KB) | DOI: 10.18860/al.v7i1.7934

Abstract

Red mangrove (Rhizophora stylosa) is one of the mangrove species which is abundance in the coast of Java. The mangrove contains a lot of active compounds that is potent as antioxidant. The objective of this study was to determine antioxidant activity of n-hexane, ethyl acetate, and methanol extract of red mangrove leaves and roots using DPPH (1,1-diphenyl-2-picrylhydrazyl) method. Active compound extraction of red mangrove is conducted by gradual maceration. According to phytochemical analysis, crude root extract showed the presence of flavonoids, tannins, and steroids/triterpenoids, while crude leave extract showed the presence of alkaloids, flavonoids, tannins, saponins, and steroids/triterpenoids. EC50 value of methanol extract from red mangrove leaves and roots was 5.01 and 2.55 ppm, respectively, whilst of ethyl acetate extracts from red mangrove leaves and roots was 89.94 and 8.51 ppm, respectively. Crude extract n-hexane has antioxidant activity 33.14 ppm (EC50). Roots and leaves extracts have high activity of antioxidant. Keywords: Antioxidant, red mangrove, DPPH method  Bakau merah (Rhizophora stylosa) merupakan salah satu spesies bakau yang keberadaannya sangat melimpah di pesisir pantai Pulau Jawa dan mengandung banyak senyawa aktif yang berpotensi sebagai antioksidan. Penelitian ini bertujuan untuk mengetahui aktifitas antioksidan ekstrak n-heksana, etil-asetat, metanol pada akar dan daun bakau merah menggunakan metode DPPH. Ekstraksi senyawa aktif pada akar dan daun dilakukan dengan metode maserasi bertingkat menggunakan n-heksana, etil asetat dan metanol. Ekstrak kasar dilakukan uji fitokimia dan aktivitas antioksidannya menggunakan metode DPPH (1,1-difenil-2-pikrilhidrazil). Hasil pengujian fitokimia dari ekstrak kasar akar menunjukkan adanya senyawa flavonoid, tanin, dan steroid/triterpenoid, sedangkan ekstrak kasar daun menunjukkan adanya alkaloid, flavonoid, tanin, saponin, dan steroid/triterpenoid. Nilai EC50 (Efficient Concentration) ekstrak metanol daun dan akar berturut-turut sebesar 5,01 dan 2,55 ppm, sedangkan ekstrak etil-asetat daun dan akar berturut-turut sebesar 89,94 dan 8,51 ppm. Adapun ekstrak n-heksana daun menghasilkan nilai EC50 sebesar 33,14 ppm. Ekstrak akar dan daun bakau merah memiliki aktivitas antioksidan yang tinggi. Kata kunci: Antioksidan, bakau merah, metode DPPH
Kinetika Adsorpsi Cangkang Telur pada Zat Warna Metilen Blue Badriyah, Lailatul; Putri, Mardiana Prasetyani
ALCHEMY Vol 5, No 3 (2017): ALCHEMY
Publisher : Department of Chemistry, Faculty of Science and Technology UIN Maulana Malik Ibrahim Malan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (517.166 KB) | DOI: 10.18860/al.v5i3.3858

Abstract

The analyze of reaction kinetic adsorption of methylene blue by egg shell was studied. Methylene Blue was one of the dye which used in industry applied. It was an organic compound that dangerous if it throw away in the river without prepraration yet. As a consequence would be object that could interfere biota aquatic. So, it need a treatment in liquid dye waste, that could reduce degree of dye. One of the treatment was adsorption. Egg shell shyntesized were analyzed by using FTIR. It was done to know some function groups that in. The reaction kinetic experiment was done to count in adsorption dye process, especially in the wastewater from textile industry. Dyes adsorption by using egg shell has equilibrium time at the 70 minutes after adsorption process. After that, the process has not a different significantly. The experiment data were fitted into the Langmuir and Freundlich isotherm. Both of the adsorption isoterm, the R2 value of Langmuir isotherm model was the highest, 0,9986. Having a As coeficient 0,3589 and Kb 0,7962. The adsorption kinetics of Methylene Blue on egg shell could be described by a pseudo second order model, with the regresion, R2 0,9979.
Structural and Photocatalytic Properties of TiO2/Zeolite Synthesized using Sol-Gel Method Nur Aini; Fahmi Eksa Sagita; Khoridatud Diyanah; Aminatus Arifah; Siti Nur Chasanah; Anton Prasetyo
ALCHEMY Vol 7, No 1 (2019): ALCHEMY: Journal of Chemistry
Publisher : Department of Chemistry, Faculty of Science and Technology UIN Maulana Malik Ibrahim Malan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (510.842 KB) | DOI: 10.18860/al.v7i1.8168

Abstract

Titanium dioxide (TiO2) is supported into natural zeolite to enhance its photocatalytic activity. TiO2/zeolite is synthesized using sol-gel method at composition ratio of 5:95; 10:90; 20:80 and 30:70%. Structural properties are measured by X-ray diffraction showed TiO2/zeolite in various composition has characteristic of anatase and modernite phase. The energy dispersive spectroscopy characterization shows TiO2/zeolite containing Ti element which indicates that TiO2is successfully supported into natural zeolite. Vibration mode of Infrared and Raman spectra tend shifted to higher wavenumber as increasing of TiO2 content indicating the higher energy vibration due to molecular interaction between TiO2 and zeolite. Photocatalytic activity test toward methylene blue degradation shows that TiO2/zeolite has higher activity than TiO2 and zeolite itself.Keywords: Photocatalyst, titanium dioxide, zeolite
Analisis Kadar Timbal (Pb) pada Bedak Tabur dan Eyeshadow dengan Variasi Metode Destruksi dan Zat Pengoksidasi dengan Spektroskopi Serapan Atom Dewi, Diana Candra; Mahmudah, RIf'atul; Kumalawati, Oktrin Rustika; Amalullia, Diana
ALCHEMY Vol 7, No 1 (2019): ALCHEMY: Journal of Chemistry
Publisher : Department of Chemistry, Faculty of Science and Technology UIN Maulana Malik Ibrahim Malan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (391.393 KB) | DOI: 10.18860/al.v7i1.7016

Abstract

Loose powder and eyeshadow are cosmetics often used by women in their daily activities. Some cosmetic products contain heavy metal in the composition. This study aims to determine the concentration of lead in the loose powder and eyeshadow both registered and unregistered at the Food and Drug Supervisory Agency (BPOM) in Malang. The destruction method used is wet digestion in the opened and closed systems with variations of oxidizing agents of HNO3 and HClO4. The concentration of lead was analyzed using atomic absorption spectroscopy (AAS). The results of destruction optimization on loose powder and eyeshadow showed wet digestion in closed system gave the best destruction results. The best oxidizing agent for both products is a mixture of HNO3: HClO4 (2: 1). Lead concentration in the loose powder product for samples A, B, C, D was 18.90±0.35, 19.10±0.46, 23.47±0.65 and 28.90±0.35mg/Kg, respectively. Eyeshadow samples of E, F, G, and H contained lead concentrations were 25.67±1.76, 34.23±0.57, 45.30±0.56 and 45.90±1.78 mg/Kg, respectivelyKeywords: cosmetics, loose powder, eyeshadow, lead  Bedak tabur dan eyeshadow merupakan kosmetik yang sering digunakan oleh wanita dalam kehidupaan sehari-hari. Beberapa produk kosmetik mengandung logam berat dalam komposisinya. Penelitian ini bertujuan untuk menentukan kadar timbal pada bedak tabur dan eyeshadow baik yang terdaftar dan tidak terdaftar di Badan Pengawas Obat dan Makanan (BPOM) di kota Malang. Metode yang digunakan adalah metode destruksi basah (terbuka dan tertutup) dengan variasi zat pengoksidasi HNO3 dan HClO4. Kadar timbal dianalisis menggunakan spektroskopi serapan atom (SSA). Hasil optimasi desktruksi pada bedak tabur dan eyeshadow menunjukkan bahwa destruksi basah tertutup memberikan hasil destruksi terbaik. Adapun pengoksidasi terbaik untuk kedua produk tersebut adalah campuran HNO3:HClO4 (2:1). Kadar timbal bedak tabur pada sampel A, B, C, D masing-masing sebesar 18,90±0,35; 19,10±0,46; 23,47±0,65 dan 28,90±0,35 mg/Kg. Sampel eyeshadow E, F, G, dan H mengandung kadar timbal sebesar 25,67±1,76; 34,23±0,57; 45,30±0,56 dan 45,90±1,78 mg/Kg, berturut-turut.Kata kunci: kosmetik, bedak tabur, eyeshadow, timbal
Distribusi Spasial Logam Berat Besi (Fe) di Perairan Teluk Staring, Sulawesi Tenggara Bahril, Bahril; Armid, Armid; Jabir, Jabir; Takwir, Amadhan; Rahim, Abdul
ALCHEMY Vol 7, No 2 (2019): ALCHEMY: Journal of Chemistry
Publisher : Department of Chemistry, Faculty of Science and Technology UIN Maulana Malik Ibrahim Malan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (496.331 KB) | DOI: 10.18860/al.v7i2.7192

Abstract

 Study on spatial distribution of metal Fe in the coastal area of Staring Bay, Southeast Sulawesi has been carried out. This study aims to determine the spatial distributions of heavy Fe in the coastal area of Staring Bay. Sampling was conducted at 12 stations along the bay through the purposive sampling method. Determination of heavy metal Fe concentration was performed utilizing the Atomic Absorption Spectrophotometry (AAS). Spatial analysis was performed with IDW interpolation method using a software ArcGIS 10.3. The results showed that the concentration of metal Fe at 12 stations was in the range of 0.00187 ppm to 0.01296 ppm whereby the highest level was found at station 7 (mouth of the Laonti river). The spatial analysis in 12 stations confirmed that in the coastal areas of Woru-woru village (near the mouth of the Laonti river) to Gala Island and Wandahea village up to Intan Island have been contaminated by metal Fe ranged from 0.0106-0.0117 ppm and 0.0118-0.013 ppm, respectively. The contamination factor of metal Fe was moderate. Based on the values of CF, the highest contamination of heavy metal Fe is at station 7. Keywords: Spatial analysis, Fe, IDW, CF, Staring Bay  Telah dilakukan studi distribusi spasial logam Fe di perairan Teluk Staring, Sulawesi Tenggara. Penelitian ini bertujuan untuk menentukan sebaran spasial logam Fe di perairan Teluk Staring. Pengambilan sampel dilakukan 12 stasiun di perairan teluk dengan metode purposive sampling. Penentuan kadar logam Fe pada sampel air laut menggunakan Atomic Absorption Spectrophotometry (AAS). Analisis spasial dilakukan dengan metode interpolasi IDW menggunakan software ArcGIS 10.3. Hasil penelitian menunjukkan bahwa kadar logam Fe di 12 stasiun penelitian berkisar antara 0,00187-0,01296 ppm dengan kadar tertinggi berada pada stasiun 7 (muara Sungai Laonti). Hasil analisis spasial pada 12 stasiun menunjukkan bahwa di daerah pesisir Desa Woru-woru (dekat muara Sungai Laonti) hingga Pulau Gala dan Desa Wandahea hingga Pulau Intan telah terkontaminasi logam Fe dengan kisaran 0,0106-0,0117 ppm dan 0,0118-0,013 ppm. Faktor kontaminasi logam Fe bersifat moderat. Berdasarkan nilai CF, kontaminasi tertinggi oleh logam Fe terdapat pada stasiun 7. Kata kunci: Analisis spasial, Fe, IDW, CF, Teluk Staring 
Sintesis Pigmen Geothit (α-FeOOH) dari Limbah Industri Kerajinan Besi dengan Metode Presipitasi Nisa, Choirun; Aini, Nur; Khoiroh, Lilik Miftahul
ALCHEMY Vol 7, No 2 (2019): ALCHEMY: Journal of Chemistry
Publisher : Department of Chemistry, Faculty of Science and Technology UIN Maulana Malik Ibrahim Malan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (318.815 KB) | DOI: 10.18860/al.v7i2.4928

Abstract

Iron handicraft is one of industries that process iron ore into handicraft products and produce lathe waste. Iron lathe contains 96.08% iron metal which is potential source as a precursor for synthesis of goethite pigment. The method used for synthesis was precipitation using NaHCO3 as precipitator agent. Synthesis was conducted at 70°C with variations of stirring speed such as 550, 650, 750 and 850 rpm. The products were characterized by color reader, ultraviolet-visible (UV-Vis) spectroscopy, XRD and SEM-EDX. The data from color reader showed that the highest yellowness degree and lightness obtained at a stirring speed 550 rpm were 24.1 and 42.1, respectively. UV-Vis data showed that the maximum wavelength of goethite pigment was 600-624 nm. Based on XRD data, synthesized pigment was in goethite phase (α-FeOOH) for all samples with crystallite size 63.24 nm and the highest crystallinity was achieved at 550 rpm. SEM-EDX data showed that morphology pigment (α-FeOOH) was not uniform, there were impurities such as Na and C. Keywords: Lathe waste, precipitation, goethite, pigment  Industri kerajinan besi merupakan salah satu industri yang mengolah bijih besi menjadi produk kerajinan dan menghasilkan limbah bubut besi. Limbah bubut besi mengandung unsur besi sebesar 96,08% yang berpotensi sebagai bahan baku (prekursor) untuk sintesis pigmen geothit. Metode yang digunakan adalah metode presipitasi dengan agen pengendap NaHCO3. Sintesis dilakukan pada suhu 70°C dengan variasi kecepatan pengadukan 550, 650, 750 dan 850 rpm. Produk hasil sintesis dikarakterisasi dengan color reader, spektroskopi ultraviolet-tampak (UV-Vis), XRD, dan SEM-EDX. Data color reader menunjukkan bahwa derajat kekuningan dan derajat kecerahan tertinggi didapatkan pada kecepatan pengadukan 550 rpm yaitu berturut-turut 24,1 dan 42,1. Data UV-Vis menunjukkan panjang gelombang maksimum pigmen geothit hasil sintesis adalah 600-624 nm. Hasil karakterisasi XRD menunjukkan bahwa pigmen hasil sintesis pada semua kecepatan pengadukan berfasa geothit (α-FeOOH) dengan derajat kristalinitas tertinggi pada kecepatan pengadukan 550 rpm dengan ukuran kristal 63,24 nm. Hasil SEM-EDX pada kecepatan 550 rpm menunjukkan bahwa morfologi pigmen (α-FeOOH) hasil sintesis tidak seragam dan ditemukan adanya pengotor berupa unsur Na dan C. Kata kunci: Limbah bubut besi, presipitasi, geothit, pigmen
Characterization of Gelatin Profile of Chicken Broiler (Gallus domestica) Bone Using SDS-PAGE Electrophoresis Yuliani, Dewi; Awalsasi, Dhienda Risa; Jannah, Akyunul
ALCHEMY Vol 7, No 1 (2019): ALCHEMY: Journal of Chemistry
Publisher : Department of Chemistry, Faculty of Science and Technology UIN Maulana Malik Ibrahim Malan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (436.444 KB) | DOI: 10.18860/al.v7i1.7437

Abstract

Gelatin, a proteinaceous additive, is obtained from hydrolysis of collagen in the bone, hide and skin of animals. As natural product, gelatin has been applied in many industries with various functions. This study attempt to characterize gelatin profile of broiler chicken (Gallus domestica) using SDS-PAGE electrophoresis. The chicken bone was pretreated using a strong base, sodium hydroxide, producing type B gelatin. The gelatin was purified through precipitation using the variation of ammonium sulfate concentrations (40-70%) and dialysis using cellophane membrane. The purified gelatin was characterized through SDS-PAGE electrophoresis. Based on electrophoresis visualization, reduction of band intensity by ammonium sulfate 40% showed removal of small peptide fragments. The remained gelatin showed two major bands, α-chains and a β-chain with the respective molecular weight of ~135 and ~245 kDa. The protein content of the unpurified gelatin (E1) was 71.65±0.60 mg/L.  The purified E1 gelatins by 40-70% of ammonium sulfate addition contained 61.42±3.90, 60.45±1.36, 59.89±0.24, and 55.32±1.05 mg/L of protein concentration, respectively. Keywords: chicken bone, gelatin profile, protein electrophoresis
Preparasi dan Karakterisasi Nanobiokatalis Mikroreaktor dengan Polimer Monolitik Nanopori Enzim Termobilisasi Anggraeny, Baiq Octaviana Dwi; Raeni, Septi F.; Iftitah, Elvina D.; Sabarudin, Akhmad
ALCHEMY Vol 5, No 3 (2017): ALCHEMY
Publisher : Department of Chemistry, Faculty of Science and Technology UIN Maulana Malik Ibrahim Malan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (896.154 KB) | DOI: 10.18860/al.v5i3.3616

Abstract

Pada penelitian ini telah dilakukan pengembangan pembuatan kolom nanobiokatalis mikroreaktor yang terimobilisasi oleh enzim tripsin pada polimer monolitik nanopori. Polimer monolitik nanopori dibuat secara in-situ kopolimerisasi  dalam kolom silicosteel (1.0 mm i.d x 100 mm) dari monomer GMA dan EDMA sebagai crosslinker serta penambahan porogen dengan komposisi 1-propanol/1,4-butanediol/air (7:4:1) dan inisiator radikal AIBN 1%. Proses polimerisasi berlangsung selama 12 jam pada suhu 60°C dengan persentase total monomer %T 40 dan persentase crosslinker %C 25. Monolit dimodifikasi secara kimia menggunakan metode imobilisasi enzim melalui reaksi pembukaan cincin epoksida dari polimer monolit terhadap tripsin. Beberapa parameter uji dilakukan untuk menghasilkan mikroreaktor pada kondisi optimum yaitu variasi waktu imobilisasi dan pengaruh penambahan glutaraldehida pada kolom tripsin monolit. Karakterisasi yang dilakukan meliputi uji ISEC untuk mengetahui ukuran dan distribusi pori monolit, SEM-EDX untuk mengetahui struktur morfologi kolom mikroreaktor, dan uji permeabilitas kolom mikroreaktor. Berdasarkan hasil ISEC proporsi mesopori dan makropori (flow-through pore) seimbang yaitu 65,85% dan 28,20%.  Hasil SEM-EDX menunjukkan kandungan nitrogen tertinggi yang mewakili jumlah tripsin yang terimobilisasi dalam monolit sebesar 12,40% dihasilkan dari tripsin monolit dengan waktu imobilisasi 4 jam tanpa penambahan glutaraldehida. Nanobiokatalis mikroreaktor pada kondisi optimum dapat digunakan untuk proses digestion sampel protein secara cepat dan efisien.
Korelasi Kadar Karboksihemoglobin terhadap Tekanan Darah Penduduk di Sekitar Terminal Bus Tirtonadi Surakarta Wimpy, Wimpy; Harningsih, Tri
ALCHEMY Vol 7, No 2 (2019): ALCHEMY: Journal of Chemistry
Publisher : Department of Chemistry, Faculty of Science and Technology UIN Maulana Malik Ibrahim Malan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (366.117 KB) | DOI: 10.18860/al.v7i2.7772

Abstract

 Carbon monoxide is a gas from incomplete combustion of fuel containing carbon. In high concentration on the blood stream, carbon monoxide is able to cause death. The affinity of hemoglobin for carbon monoxide is higher than that of oxygen. Blood clotting because of high concentration carbon monoxide in the blood can increase blood viscosity and causes vasoconstriction. This study aims to determine the correlation between carboxyhaemoglobin (COHb) and blood pressure of the resident living around Tirtonadi Bus Station, Surakarta. The concentration of COHb was analyzed using UV-Vis Spectrophotometer. The COHb concentration of A1, A2, A3, A4, A5, A6, A7, A8, A9, A10 samples was 6.51, 6.28, 6.22, 6.23, 6.21, 6.17, 6.17, 6.11, 6.15, and 6.12%, respectively. The result of the test was analyzed by SPSS. The result of normality test does not show normal distribution data. Statistical analysis was conducted by using Spearman. There is a significant value of systole (0.027) and diastole (0.011). There is a correlation between COHb concentration and blood pressure of the resident living around Tirtonadi Bus Station, Surakarta. Keywords: Carboxyhaemoglobin, blood pressure, Tirtonadi bus station  Karbon monoksida adalah gas polutan yang berasal dari produk pembakaran yang tidak sempurna dari bahan bakar yang mengandung karbon. Pada konsentrasi tinggi dalam darah, gas ini dapat menyebabkan kematian. Afinitas karbon monoksida lebih besar dari pada dengan oksigen. Kadar karbon monoksida yang tinggi di dalam aliran darah akan membentuk bekuan darah sehingga akan meningkatkan kekentalan darah. Hal ini dapat menyebabkan terjadinya vasokonstriksi sehingga akan menaikan tekanan darah. Tujuan penelitian ini untuk mencari hubungan antara kadar karboksihemoglobin (COHb) terhadap tekanan darah penduduk yang tinggal di sekitar Stasiun Bus Tirtonadi, Surakarta. Pengukuran kadar COHb menggunakan Spektrofotometer UV-Vis. Hasil uji kadar COHb pada kode sampel A1, A2, A3, A4, A5, A6, A7, A8, A9, dan A10 masing-masing sebesar 6,51; 6,28; 6,22; 6,23; 6,21; 6,17; 6,17; 6,11; 6,15 dan 6,12%. Hasil data dianalisis dengan SPSS. Hasil uji normalitas tidak menunjukkan data distribusi normal. Pengukuran statistik dilakukan dengan menggunakan uji Spearman. Hasil penelitian menunjukkan nilai signifikan sistol sebesar 0,027 dan diastol sebesar 0,011. Ada korelasi antara kadar COHb dengan tekanan darah pada penduduk yang tinggal di sekitar Terminal Tirtonadi, Surakarta. Kata kunci: Karboksihemoglobin, tekanan darah, Terminal Tirtonadi 
Adsorpsi Logam Ni dan Cu pada Limbah Cair Laboratorium Kimia menggunakan Biosorben Batang Jagung Termodifikasi Asam Sitrat Yulianti, Eny; Mahmudah, RIf'atul; Ma'rifah, Ainul; Azmiyani, Ulal
ALCHEMY Vol 7, No 1 (2019): ALCHEMY: Journal of Chemistry
Publisher : Department of Chemistry, Faculty of Science and Technology UIN Maulana Malik Ibrahim Malan

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (625.925 KB) | DOI: 10.18860/al.v7i1.7933

Abstract

Corn stalk contains 40-50% cellulose, 20-40% hemicellulose, 4-15% lignin which had potential as biosorbent in binding metal ions. In this study, demineralization and modification by adding citric acid (1.5 M and 2 M) of corn stalk were conducted to convert hydroxyl groups into carboxylic. Then, it was analyzed its functional groups using Boehm titration and FTIR. The modified corn stalk was applied directly to chemical laboratory liquid waste which contains multicomponent of heavy metal ions. By modifying the corn stalk, the number of hydroxyl and carboxylic groups increased, but the number of lactone group was constant. The success of the modification was characterized by the appearance of ester uptake at 1734 cm-1 and increased adsorption ability. The variations in the concentration of citric acid in modification corn stalk showed that biosorbent with addition 1.5 M citric acid had higher in the number of acid site than addition 2 M citric acid to absorb Ni and Cu.  Keywords: Corn stalk, citric acid, biosorbent, functional group  Batang jagung mengandung sekitar 40-50% selulosa, 20-40% hemiselulosa, 4-15% lignin yang berpotensi sebagai biosorben pengikat ion logam. Pada penelitian ini dilakukan demineralisasi dan modifikasi dengan penambahan asam sitrat (1,5 M dan 2 M) untuk mengubah gugus hidroksil pada selulosa membentuk karboksilat. Selanjutnya, dianalisis gugus fungsinya menggunakan titrasi Boehm dan FTIR. Hasil modifikasi diaplikasikan langsung pada limbah cair laboratorium kimia yang mengandung banyak jenis ion logam berat. Biosorben batang jagung setelah dimodifikasi mengalami peningkatan jumlah gugus fungsi hidroksil dan karboksilat, tetapi gugus lakton tetap. Keberhasilan modifikasi ditandai dengan munculnya serapan ester pada 1734 cm-1 dan peningkatan kemampuan adsorpsi. Dari hasil variasi konsentrasi asam sitrat diperoleh informasi bahwa biosorben dengan penambahan asam sitrat 1,5 M mempunyai situs asam lebih tinggi dan mempunyai kemampuan adsorpsi terhadap ion logam Ni dan Cu lebih besar dibanding penambahan asam sitrat 2 M. Kata kunci:  Batang jagung, asam sitrat, biosorben, gugus fungsi