Jurnal Kimia Unand

Analisis Kandungan Formalin dan Boraks dalam Mi Kuning, Kerupuk Merah, dan Ayam Menggunakan Metode Rapid Test Kit dan Spektrofotometri UV-Vis

2023-12-04T12:13:48+07:00

Food is one of human’s primary needs to survive and carry out their activities. Food must be safe, nutritious, and high quality when it’s consumed. In order to maintain food quality, some food ingredients, such as yellow noodles, crackers, and chicken, are often added with formaldehyde and borax, which are dangerous ingredients that are prohibited use as Food Additives (BTP) because their health hazards in accordance with Regulation of Minister Health No. 033 of 2012 and Regulation of BPOM No. 22 of 2023. Therefore, this research aims to identify qualitatively and determine the formaldehyde and borax levels quantitatively in yellow noodles, red crackers, and chicken as an effort to ensure the food safety. The method used in qualitative analysis is a rapid test kit and quantitative is UV-Vis spectrophotometry at a wavelength of 412 nm for formaldehyde and 551 nm for borax. The results of the qualitative analysis test showed that the yellow noodle sample contained formaldehyde and borax as indicated by the color change of the test stick to purple and red, respectively. Meanwhile, according to quantitative analysis, yellow noodles also contained formaldehyde and borax with average levels of 479.09 mg/kg and 44.43 mg/kg, respectively. Red crackers and chicken samples are free from formaldehyde and borax content.

Sintesis Lapis Empat Fasa Aurivillius Ca1-xBaxBi3,5La0,5Ti4O15 Dengan Metode Lelehan Garam

2024-05-05T22:33:57+07:00

The four-layer Aurivillius phase Ca_1-xBa_xBi_3.5La_0.5Ti₄O₁₅ (x = 0.2, 0.4, 0.6, 0.8, and 1) has been synthesized by molten salt method. The effect of varying x on the structure, morphology, and dielectric properties was studied. X-ray diffraction (XRD) and Le Bail refinement revealed that the compounds with the composition x = 0, 0.2, and 0.4 were single-phase product with orthorhombic A2₁am structure, whereas for higher x value (composition of Ba doped), a Ba₂TiO₄ impurity is found in products. Changes in unit cell volume were investigated, and the size increased with larger x. The substitution of larger Ba²⁺ ions resulted in a shorter Ti-O bond, shifting vibration mode to higher wave number that showed in FTIR spectra. SEM images show anisotropic plate-like grain with distributed particle sizes at 1.9 – 3.1μm. The dielectric constant values decrease with increasing x, otherwise the dielectric loss values increase for x = 0 and 0.2, however decrease for x = 0.4. The resulting Aurivillius compound has potential for applications in ferroelectric and piezoelectric devices.

Penanggulangan Limbah Ubi Kayu dengan Menggunakan Katalis TiO2/Zeolit Alam Clinoptilolit-Ca secara Sinergi Fotokatalis dan Adsorpsi

2024-03-26T12:38:50+07:00

Cassava waste containing cyanogenic glycosides is very dangerous for the environment because there is cyanide bound to organic compounds. Cyanide bound to organic compounds is degraded by photolysis using TiO₂ catalyst/Clinoptilolite-Ca natural zeolite to break the bond between HCN and organic compounds so that it is no longer harmful to the environment, besides that cassava waste also contains suspended solids and organic compounds that affect water quality, resulting in high COD, BOD, TOC, and TSS values in waters. Therefore, the values of COD, BOD, TOC, and TSS were determined before and after degradation. In addition, the effect of time, mass, and type of catalyst (TiO₂, Zeolite, and TiO₂/Zeolite) on the percentage of cassava waste degradation was also determined. CN^- analysis was performed with a UV-VIS spectrophotometer, where maximum absorption occurred at a wavelength of 573 nm. The optimum time of degradation without catalyst is 75 minutes with a degradation percentage of 20.52%, the optimum mass of TiO₂/Zeolite catalyst is 0.8 grams with a degradation percentage of 79.97% at 60 minutes, the percentage of degradation using 0.03 grams of TiO₂ is 58.65% at 75 minutes, the percentage of degradation using 0.77 zeolite is 35.43% at 75 minutes. COD value before degradation 1406 mg/L and after degradation 465 mg/L. BOD value before degradation 226 mg/L and after degradation 95.4 mg/L. TSS value before degradation 400 mg/L and after degradation 220 mg/L. While the TOC value before degradation was 546 mg/L and after degradation was 670 mg/L. FTIR analysis of cassava waste shows a peak shift indicating degradation, the 750-1000 cm^-1and 1250-1500 cm^-1. While the characterization of the TiO₂/zeolite catalyst in FTIR and XRD showed no change in the structure of the TiO₂/zeolite catalyst before and after degradation.

Perlindungan Baja Ringan Dalam Medium Asam Klorida Menggunakan Ekstrak Daun Sungkai (Peronema canescens Jack)

2024-05-01T12:32:20+07:00

Corrosion inhibition of mild steel in 1 M hydrochloric acid (HCl) by leaves extract of sungkai (Peronema canescens Jack) was studied by weight loss method, Fourier Transform Infra-Red (FTIR), spectroscopy UV-Vis, and optical microscopy. The corrosion rate of mild steel increase with the increase of temperature and decrease with the increase of concentration from leaves extract of sungkai in medium. The weight loss method shows that the inhibition efficiency increased with concentration and increases with temperature increase. The highest inhibition efficiency was 90.70% with the addition of 10 g/L extracts at 60ºC. The adsorption of the inhibitor on the surface of mild steel follows the Langmuir adsorption isotherm because it forms a monolayer. Analysis of FTIR and UV-vis spectroscopy showed an interaction between leaves extract of sungkai and mild steel surface. Optical microscopy analysis revealed differences in the surface of mild steel immersed in 1 M HCl medium with and without the addition of extract.

Penentuan Kandungan Metabolit Sekunder, Fenolik Total serta Uji Aktivitas Antibakteri dan Antijamur Ekstrak Daun Sungkai (Peronema canescens Jack) di Kabupaten Agam dan Kota Padang

2024-04-17T11:04:13+07:00

Sungkai (Peronema canescens Jack) is the traditional medicinal plants used in Indonesia. The purpose of this study was to determine the content of secondary metabolites, total phenolic content and test the antibacterial and antifungal activity of Sungkai plant leaf extract. Extraction was carried out by gradual maceration using 3 solvents with different polarity, starting from hexane, ethyl acetate and methanol. The results showed that the phytochemical profile of Sungkai leaves contained flavonoids, phenolics, saponins, triterpenoids, steroids and alkaloids. In the total phenolic test using the Folin-Ciocalteau method. The highest total phenolic content was found in the methanol extract of 195.8 mgGAE/g sample for the Padang City. The antibacterial and antifungal activity of Sungkai leaf extract were tested using the Well diffusion method. The largest diameter of the clear zone on antibacterial activity was produced in the ethyl acetate extract of the Kab. Agam with a concentration of 50% is 7 mm in Escherichia coli bacteria and 5.6 mm in Staphylococcus aureus bacteria. The highest antifungal activity against Candida albicans was produced in the ethyl acetate extract of the Padang City area of 6.4 mm. The ability of the extract activity is still much lower when compared to the positive control