Pub Date : 2023-02-14DOI: 10.20527/jstk.v17i1.9150
D. R. Gusti, Nelson Nelson, I. Lestari, Putri Ramadhanti, Ria Gracia Sibarani
{"title":"Corrosion Inhibition Mechanism Based on Adsorption Isotherm Model From Water Extract of Merkubung (Macaranga gigantea) Bark Extract on Mild Steel in Sulfuric Acid Solution","authors":"D. R. Gusti, Nelson Nelson, I. Lestari, Putri Ramadhanti, Ria Gracia Sibarani","doi":"10.20527/jstk.v17i1.9150","DOIUrl":"https://doi.org/10.20527/jstk.v17i1.9150","url":null,"abstract":"","PeriodicalId":155441,"journal":{"name":"Jurnal Berkala Ilmiah Sains dan Terapan Kimia","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130014173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-14DOI: 10.20527/jstk.v17i1.12622
Mersiana Bria Mosa, H. E. Wogo, D. Darmakusuma
{"title":"The Effect of Rice Varieties on Silica Purification from Rice Husk Ash as Adsorbent for Mn(II)","authors":"Mersiana Bria Mosa, H. E. Wogo, D. Darmakusuma","doi":"10.20527/jstk.v17i1.12622","DOIUrl":"https://doi.org/10.20527/jstk.v17i1.12622","url":null,"abstract":"","PeriodicalId":155441,"journal":{"name":"Jurnal Berkala Ilmiah Sains dan Terapan Kimia","volume":"304 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122247550","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-14DOI: 10.20527/jstk.v17i1.13948
A. Atikah, Burhanuddin Ronggopuro
Microscale laboratory is an analytical technique that requires a little reagent and produces a little waste. One application of microscale laboratory is the analysis of formaldehyde content in tofu. Formaldehyde is one of the chemicals that is harmful to the body but is often misused as a food preservative in tofu. This study aims at determining the presence of formaldehyde in tofu using laboratory microscale-based Schiff reagents. The use of microscale laboratories is expected to reduce waste and support the implementation of green chemistry. The method used was a calibration curve using a series of standard solutions of 10 ppm, 15 ppm, 20 ppm, 25 ppm, and 30 ppm with scanning at a wavelength of 561 nm. In the qualitative test, all samples were reactive and showed a purplish red color. In the qualitative test, the highest formaldehyde content in the tofu sample was obtained in the white tofu 3 with a content of 99.7 ppm.
{"title":"Study of Formaldehyde Content in Different Types of Tofu Using Micro Scale Laboratory Based Visible Beam Spectrophotometry","authors":"A. Atikah, Burhanuddin Ronggopuro","doi":"10.20527/jstk.v17i1.13948","DOIUrl":"https://doi.org/10.20527/jstk.v17i1.13948","url":null,"abstract":"Microscale laboratory is an analytical technique that requires a little reagent and produces a little waste. One application of microscale laboratory is the analysis of formaldehyde content in tofu. Formaldehyde is one of the chemicals that is harmful to the body but is often misused as a food preservative in tofu. This study aims at determining the presence of formaldehyde in tofu using laboratory microscale-based Schiff reagents. The use of microscale laboratories is expected to reduce waste and support the implementation of green chemistry. The method used was a calibration curve using a series of standard solutions of 10 ppm, 15 ppm, 20 ppm, 25 ppm, and 30 ppm with scanning at a wavelength of 561 nm. In the qualitative test, all samples were reactive and showed a purplish red color. In the qualitative test, the highest formaldehyde content in the tofu sample was obtained in the white tofu 3 with a content of 99.7 ppm.","PeriodicalId":155441,"journal":{"name":"Jurnal Berkala Ilmiah Sains dan Terapan Kimia","volume":"135 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123227853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-02-14DOI: 10.20527/jstk.v17i1.14362
Nurul Indriani, Muhammad Eka Putra Ramandha
Isolation and identification of Pinostrobin compounds in Temu Kunci Rhizomes (Kaempferia pandurata Roxb) were conducted in this study. The isolation and identification methods used were extraction, crystallization & recrystallization, Thin Layer Chromatography, and (4) Infrared (IR) Testing. The extraction results were followed by crystallization and recrystallization processes. The recrystallization produced a yellow solid isolate. A Thin Layer Chromatography test was carried out to determine the purity of the isolate using the eluent Chloroform : n-hexane of 6:4, Chloroform : Ethylacetate of 7:3. A comparison of the Retention Factor (Rf), and the Rf value of the phinostrobin standard indicates that the positive test sample contained the Pinostrobin compound. The Infrared spectrum indicates that the sample belongs to the flavonol group. It is confirmed from the functional groups of the isolates that are compatible or identical to the functional groups in the pinostrobin compound.
{"title":"ISOLATION PINOSTROBIN COMPOUND IN TEMU KUNCI (KAEMPFERIA PANDURATA ROXB) RHIZOME","authors":"Nurul Indriani, Muhammad Eka Putra Ramandha","doi":"10.20527/jstk.v17i1.14362","DOIUrl":"https://doi.org/10.20527/jstk.v17i1.14362","url":null,"abstract":"Isolation and identification of Pinostrobin compounds in Temu Kunci Rhizomes (Kaempferia pandurata Roxb) were conducted in this study. The isolation and identification methods used were extraction, crystallization & recrystallization, Thin Layer Chromatography, and (4) Infrared (IR) Testing. The extraction results were followed by crystallization and recrystallization processes. The recrystallization produced a yellow solid isolate. A Thin Layer Chromatography test was carried out to determine the purity of the isolate using the eluent Chloroform : n-hexane of 6:4, Chloroform : Ethylacetate of 7:3. A comparison of the Retention Factor (Rf), and the Rf value of the phinostrobin standard indicates that the positive test sample contained the Pinostrobin compound. The Infrared spectrum indicates that the sample belongs to the flavonol group. It is confirmed from the functional groups of the isolates that are compatible or identical to the functional groups in the pinostrobin compound.","PeriodicalId":155441,"journal":{"name":"Jurnal Berkala Ilmiah Sains dan Terapan Kimia","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-02-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128257847","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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