Pub Date : 2019-01-01DOI: 10.17576/mjas-2019-2301-03
Malaysian Journal, P. W. Chia, P. Chee, Mohd Zohirul Haziq Aziz, Siti Fairuz Mohd Radzi, Su-Yin Kan
Isoindoline-1,3-dione derivatives are important organic compounds associated with various interesting applications such as in the fields of material science, medicine, important building blocks and so on. Traditionally, the synthesis of isoindoline-1,3-dione derivatives are achieved using harmful and toxic catalysts, such as concentrated sulphuric acid, triphenylphosphine, ionic liquid [bmim][BF4] or phthalimide-N-sulfonic acid. Thus, the development of a greener catalytic system for the synthesis of isoindoline-1,3-dione derivatives is highly sought after. In this work, an efficient synthesis of isoindoline-1,3-dione derivatives using the Water Extract of Onion Peel Ash (WEOPA) method is described. The new approach provides several advantages including the non-usage of external acids, recyclable catalytic system, cheap and the yield of the synthesized products were obtained in moderate to good yields by reacting various anilines with phthalic anhydride. The current improved method is scientifically important, due to it avoid the use of environmental harmful reagents and at the same time provides an alternative method for bio-waste management.
异吲哚-1,3-二酮衍生物是一种重要的有机化合物，在材料科学、医学、重要的建筑材料等领域有着广泛的应用。传统上，异吲哚-1,3-二酮衍生物的合成是使用有害和有毒的催化剂，如浓硫酸、三苯基膦、离子液体[bmim][BF4]或邻苯二胺- n -磺酸。因此，开发一种更环保的催化系统来合成异吲哚-1,3-二酮衍生物备受追捧。本文报道了一种利用洋葱皮灰水提物(WEOPA)高效合成异吲哚-1,3-二酮衍生物的方法。该方法具有不使用外源酸、催化体系可循环利用、成本低、各种苯胺与邻苯二甲酸酐反应合成产物收率中高等优点。目前改进的方法具有重要的科学意义，因为它避免了对环境有害的试剂的使用，同时为生物废物的管理提供了一种替代方法。
{"title":"WATER EXTRACT OF ONION PEEL ASH: AN EFFICIENT GREEN CATALYTIC SYSTEM FOR THE SYNTHESIS OF ISOINDOLINE-1,3-DIONE DERIVATIVES","authors":"Malaysian Journal, P. W. Chia, P. Chee, Mohd Zohirul Haziq Aziz, Siti Fairuz Mohd Radzi, Su-Yin Kan","doi":"10.17576/mjas-2019-2301-03","DOIUrl":"https://doi.org/10.17576/mjas-2019-2301-03","url":null,"abstract":"Isoindoline-1,3-dione derivatives are important organic compounds associated with various interesting applications such as in the fields of material science, medicine, important building blocks and so on. Traditionally, the synthesis of isoindoline-1,3-dione derivatives are achieved using harmful and toxic catalysts, such as concentrated sulphuric acid, triphenylphosphine, ionic liquid [bmim][BF4] or phthalimide-N-sulfonic acid. Thus, the development of a greener catalytic system for the synthesis of isoindoline-1,3-dione derivatives is highly sought after. In this work, an efficient synthesis of isoindoline-1,3-dione derivatives using the Water Extract of Onion Peel Ash (WEOPA) method is described. The new approach provides several advantages including the non-usage of external acids, recyclable catalytic system, cheap and the yield of the synthesized products were obtained in moderate to good yields by reacting various anilines with phthalic anhydride. The current improved method is scientifically important, due to it avoid the use of environmental harmful reagents and at the same time provides an alternative method for bio-waste management.","PeriodicalId":39007,"journal":{"name":"Malaysian Journal of Analytical Sciences","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67646774","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 : 2019-01-01DOI: 10.17576/mjas-2019-2301-15
Malaysian Journal, Pengeringan Etanol, Menggunakan Zat Larut, Ternari dan Penyulingan, Kelompok Hasil Ekstrak, T. Marnoto, Chintya Rizki Hapsari, Angga Y. Prakosa
Anhydrous bioethanol is a material used in many applications including biofuel. Commonly, bioethanol is produced through sugar fermentation which results in a low concentration of ethanol. For utilization as biofuel, the lowest ethanol concentration should be 99.5%. Distillation is common technique to dry a mixture solution, however, the mixture of bioethanol and water is forming an azeotrope that limit the concentration of 96% ethanol. This paper discusses ethanol dehydration through extractive batch distillation by the addition of a ternary solute sodium hydroxide, citric acid, sulfuric acid, glycerol or ethylene glycol to ethanol. The initial concentration of ethanol used was 86% v/v, and the amount of ternary solute added was selected based on the colligative properties of the solution, which included a boiling point elevation (ΔTB) that ranged from 5 to 25 °C. All the ternary solutes could break or shift the ethanol-water azeotrope. The highest concentration of ethanol was 99.91% v/v at ΔTB = 25 °C with sulfuric acid as the ternary component. The resulted ethanol concentration exhibited a linear relationship with ΔTB, which was also affected by the boiling point of the ternary solute. This study successfully produced anhydrous bioethanol by low cost and simple distillation process.
{"title":"DEHYDRATING ETHANOL USING A TERNARY SOLUTE AND EXTRACTIVE BATCH DISTILLATION","authors":"Malaysian Journal, Pengeringan Etanol, Menggunakan Zat Larut, Ternari dan Penyulingan, Kelompok Hasil Ekstrak, T. Marnoto, Chintya Rizki Hapsari, Angga Y. Prakosa","doi":"10.17576/mjas-2019-2301-15","DOIUrl":"https://doi.org/10.17576/mjas-2019-2301-15","url":null,"abstract":"Anhydrous bioethanol is a material used in many applications including biofuel. Commonly, bioethanol is produced through sugar fermentation which results in a low concentration of ethanol. For utilization as biofuel, the lowest ethanol concentration should be 99.5%. Distillation is common technique to dry a mixture solution, however, the mixture of bioethanol and water is forming an azeotrope that limit the concentration of 96% ethanol. This paper discusses ethanol dehydration through extractive batch distillation by the addition of a ternary solute sodium hydroxide, citric acid, sulfuric acid, glycerol or ethylene glycol to ethanol. The initial concentration of ethanol used was 86% v/v, and the amount of ternary solute added was selected based on the colligative properties of the solution, which included a boiling point elevation (ΔTB) that ranged from 5 to 25 °C. All the ternary solutes could break or shift the ethanol-water azeotrope. The highest concentration of ethanol was 99.91% v/v at ΔTB = 25 °C with sulfuric acid as the ternary component. The resulted ethanol concentration exhibited a linear relationship with ΔTB, which was also affected by the boiling point of the ternary solute. This study successfully produced anhydrous bioethanol by low cost and simple distillation process.","PeriodicalId":39007,"journal":{"name":"Malaysian Journal of Analytical Sciences","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67647335","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 : 2019-01-01DOI: 10.17576/mjas-2019-2303-15
M. Jannatin, Ayu Nabila Izazi Latjuba, S. Wahyuni, G. Supriyanto, W. A. Ibrahim
An analytical method for the determination of histamine using metals and alizarin red S (ARS) reagents by UV-Visible spectrophotometry was developed. Cu(II), Co(II) and ARS were used to form colored complex with histamine. The developed method was used to detect qualitatively and quantitatively the presence of histamine. Absorbance of Cu(II) and Co(II) complex were measured at a maximum wavelength of 505.5 and 567 nm, respectively. Optimization of analytical parameters such as concentration of metals, concentration of ARS, sample solution pH, and optimum time for complex formation were performed. Experimental results showed that the optimum concentration of Cu(II) was 50 ppm, 75 ppm ARS, sample solution pH 6, and 15 minutes optimum time, while the optimum concentration of Co(II) was 125 ppm, ARS was 75 and 50 ppm, sample solution pH 5 and 10 minutes optimum time. Method validation indicated that the coefficient of variation, limit of detection (LOD) (S/N =3), and limit of quantitation (LOQ = 10S/N) of Cu(II) were 0.65%, 8.94 ppm, and 29.82 ppm respectively with a sensitivity of 0.0054 ppm and linearity of 0.9959. Accuracy of histamine determination through Cu-ARS-histamine complex at a concentration of 50, 100, and 150 ppm were 105.7% (RSD = 0.777%, n = 3), 105.06% (RSD = 0.606%, n = 3), and 94.12% (RSD = 0.767%, n = 3), respectively. Meanwhile, the CV, LOD, and LOQ of Co(II) were 0.28%; 2.58 ppm; and 8.6 ppm respectively with a sensitivity of 0.0006 ppm and linearity of 0.9965. Accuracy of histamine determination through Co-ARS-histamine complex at a concentration of 50, 75, and 125 ppm were 98.33%, 95.83%, 93.88%, respectively. The proposed method was successfully applied to the determination of histamine in a fish sample with quantitative recovery; for Cu(II) complex (99.23%) and Co(II) complex (102.62%).
建立了用金属和茜素红S (ARS)试剂联合紫外可见分光光度法测定组胺的分析方法。Cu(II)、Co(II)和ARS与组胺形成有色络合物。本方法可用于组胺的定性和定量检测。Cu(II)和Co(II)配合物在最大波长分别为505.5 nm和567 nm处的吸光度。对金属浓度、ARS浓度、样品溶液pH、络合物形成最佳时间等分析参数进行了优化。实验结果表明，Cu(II)的最佳浓度为50 ppm、75 ppm ARS，样品溶液pH为6，最佳时间为15 min; Co(II)的最佳浓度为125 ppm, ARS为75、50 ppm，样品溶液pH为5，最佳时间为10 min。方法验证表明，Cu(II)的变异系数为0.65%，检出限为8.94 ppm，定量限为10S/N，灵敏度为0.0054 ppm，线性度为0.9959。cu - ars -组胺复合物在50、100和150 ppm浓度下测定组胺的准确度分别为105.7% (RSD = 0.777%， n = 3)、105.06% (RSD = 0.606%， n = 3)和94.12% (RSD = 0.767%， n = 3)。Co(II)的CV、LOD和LOQ分别为0.28%;2.58 ppm;灵敏度为0.0006 PPM，线性度为0.9965。在50、75、125 ppm浓度下，co - ars -组胺复合物测定组胺的准确度分别为98.33%、95.83%、93.88%。该方法成功地应用于鱼样品中组胺的定量测定。Cu(II)配合物(99.23%)和Co(II)配合物(102.62%)。
{"title":"RAPID SPECTROPHOTOMETRIC METHOD FOR HISTAMINE DETERMINATION IN FISH USING ALIZARIN RED S AND METAL","authors":"M. Jannatin, Ayu Nabila Izazi Latjuba, S. Wahyuni, G. Supriyanto, W. A. Ibrahim","doi":"10.17576/mjas-2019-2303-15","DOIUrl":"https://doi.org/10.17576/mjas-2019-2303-15","url":null,"abstract":"An analytical method for the determination of histamine using metals and alizarin red S (ARS) reagents by UV-Visible spectrophotometry was developed. Cu(II), Co(II) and ARS were used to form colored complex with histamine. The developed method was used to detect qualitatively and quantitatively the presence of histamine. Absorbance of Cu(II) and Co(II) complex were measured at a maximum wavelength of 505.5 and 567 nm, respectively. Optimization of analytical parameters such as concentration of metals, concentration of ARS, sample solution pH, and optimum time for complex formation were performed. Experimental results showed that the optimum concentration of Cu(II) was 50 ppm, 75 ppm ARS, sample solution pH 6, and 15 minutes optimum time, while the optimum concentration of Co(II) was 125 ppm, ARS was 75 and 50 ppm, sample solution pH 5 and 10 minutes optimum time. Method validation indicated that the coefficient of variation, limit of detection (LOD) (S/N =3), and limit of quantitation (LOQ = 10S/N) of Cu(II) were 0.65%, 8.94 ppm, and 29.82 ppm respectively with a sensitivity of 0.0054 ppm and linearity of 0.9959. Accuracy of histamine determination through Cu-ARS-histamine complex at a concentration of 50, 100, and 150 ppm were 105.7% (RSD = 0.777%, n = 3), 105.06% (RSD = 0.606%, n = 3), and 94.12% (RSD = 0.767%, n = 3), respectively. Meanwhile, the CV, LOD, and LOQ of Co(II) were 0.28%; 2.58 ppm; and 8.6 ppm respectively with a sensitivity of 0.0006 ppm and linearity of 0.9965. Accuracy of histamine determination through Co-ARS-histamine complex at a concentration of 50, 75, and 125 ppm were 98.33%, 95.83%, 93.88%, respectively. The proposed method was successfully applied to the determination of histamine in a fish sample with quantitative recovery; for Cu(II) complex (99.23%) and Co(II) complex (102.62%).","PeriodicalId":39007,"journal":{"name":"Malaysian Journal of Analytical Sciences","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67647279","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 : 2019-01-01DOI: 10.17576/mjas-2019-2302-08
I. H. A. Ripain, N. Roslan, Nurul Shazana Norshahimi, S. M. Salleh, Noraslinda M. Bunnori, N. Ngah
The emergence of antibiotic resistance against bacterial strains has attracted great interest in the discovery and development of new antibacterial agents. Thiazole derivatives have been widely used in the biological as well as pharmacological fields and their efficiency as pharmaceutical drugs are well established. In this study, a series of thiazole derivatives were synthesized in reaction between 3-chloroacetyl acetone and ammonium thiocyanate followed by incorporating selected primary amines in one-pot synthesis manner. The compounds were structurally characterized by FTIR, 1H NMR, UV-Vis and GC-MS. Their antibacterial properties were screened using disc diffusion technique against Gram positive (B. cereus and S. epidermidis) as well as Gram negative (E.coli and P. aeruginosa) bacterial strains. The compound of T3 exhibited the most potent antibacterial activity. Molecular docking studies were also performed against Glucosamine-6-phosphate (GlcN-6-P) synthase which is known as the essential building block of most bacteria. According to the docking result, T3 exhibited the minimum binding energy of -7.09 kcal mol-1 as compared to T1 and T2 with -6.49 and 6.76 kcal mol-1,respectively which is in agreement with antibacterial result. The output of this preliminary study will contribute in structural enhancement in drug discovery.
{"title":"SYNTHESIS AND MOLECULAR DOCKING OF 2,4,5-TRISUBSTITUTED-1,3-THIAZOLE DERIVATIVES AS ANTIBACTERIAL AGENTS","authors":"I. H. A. Ripain, N. Roslan, Nurul Shazana Norshahimi, S. M. Salleh, Noraslinda M. Bunnori, N. Ngah","doi":"10.17576/mjas-2019-2302-08","DOIUrl":"https://doi.org/10.17576/mjas-2019-2302-08","url":null,"abstract":"The emergence of antibiotic resistance against bacterial strains has attracted great interest in the discovery and development of new antibacterial agents. Thiazole derivatives have been widely used in the biological as well as pharmacological fields and their efficiency as pharmaceutical drugs are well established. In this study, a series of thiazole derivatives were synthesized in reaction between 3-chloroacetyl acetone and ammonium thiocyanate followed by incorporating selected primary amines in one-pot synthesis manner. The compounds were structurally characterized by FTIR, 1H NMR, UV-Vis and GC-MS. Their antibacterial properties were screened using disc diffusion technique against Gram positive (B. cereus and S. epidermidis) as well as Gram negative (E.coli and P. aeruginosa) bacterial strains. The compound of T3 exhibited the most potent antibacterial activity. Molecular docking studies were also performed against Glucosamine-6-phosphate (GlcN-6-P) synthase which is known as the essential building block of most bacteria. According to the docking result, T3 exhibited the minimum binding energy of -7.09 kcal mol-1 as compared to T1 and T2 with -6.49 and 6.76 kcal mol-1,respectively which is in agreement with antibacterial result. The output of this preliminary study will contribute in structural enhancement in drug discovery.","PeriodicalId":39007,"journal":{"name":"Malaysian Journal of Analytical Sciences","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67647501","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 : 2019-01-01DOI: 10.17576/mjas-2019-2301-14
K. Cahyari, M. Hidayat, S. Syamsiah, Sarto
This research was aimed to optimize hydrogen production from fruit waste, particularly on the effect of the substrate-toinoculum ratio (SIR). Production of hydrogen was carried out through dark fermentation process both in mesophilic (30 °C, 1 atm) and thermophilic (55 °C, 1 atm) condition. Fermentation was conducted at SIR value ranging from 0.800 to 174 VSsubstrate/g VSinoc. In mesophilic fermentation, the highest cumulative total gas yield was achieved at SIR value of 19 corresponding total gas yield of 113 ml STP/g VS (5%v of H2). In thermophilic condition, the highest H2 yield was obtained at SIR value of 0.800 VSsubstrate/g VSinoc with H2 yield of 294 mL STP/g VS (50 – 60%v of purity). It was noticed that the lower SIR value, the higher hydrogen yield. In summary, it is concluded that substrate-to-inoculum ratio (SIR) plays important role in dark fermentation process to produce renewable energy of hydrogen fuel.
本研究旨在优化水果废弃物产氢，特别是对底物与接种量比(SIR)的影响。在中温(30°C, 1 atm)和亲热(55°C, 1 atm)条件下进行暗发酵制氢。发酵的SIR值为0.800 ~ 174 VSsubstrate/g VSinoc。在中温发酵中，SIR值为19时的累积总产气量最高，对应的总产气量为113 ml STP/g VS (5%v H2)。在嗜热条件下，SIR值为0.800 VSsubstrate/g VSinoc时H2得率最高，H2得率为294 mL STP/g VS(纯度为50 - 60%v)。注意到SIR值越低，产氢率越高。综上所述，底物与接种量比(SIR)在暗发酵生产可再生能源氢燃料过程中起着重要作用。
{"title":"OPTIMIZATION OF HYDROGEN PRODUCTION FROM FRUIT WASTE THROUGH MESOPHILIC AND THERMOPHILIC DARK FERMENTATION: EFFECT OF SUBSTRATE-TO-INOCULUM RATIO","authors":"K. Cahyari, M. Hidayat, S. Syamsiah, Sarto","doi":"10.17576/mjas-2019-2301-14","DOIUrl":"https://doi.org/10.17576/mjas-2019-2301-14","url":null,"abstract":"This research was aimed to optimize hydrogen production from fruit waste, particularly on the effect of the substrate-toinoculum ratio (SIR). Production of hydrogen was carried out through dark fermentation process both in mesophilic (30 °C, 1 atm) and thermophilic (55 °C, 1 atm) condition. Fermentation was conducted at SIR value ranging from 0.800 to 174 VSsubstrate/g VSinoc. In mesophilic fermentation, the highest cumulative total gas yield was achieved at SIR value of 19 corresponding total gas yield of 113 ml STP/g VS (5%v of H2). In thermophilic condition, the highest H2 yield was obtained at SIR value of 0.800 VSsubstrate/g VSinoc with H2 yield of 294 mL STP/g VS (50 – 60%v of purity). It was noticed that the lower SIR value, the higher hydrogen yield. In summary, it is concluded that substrate-to-inoculum ratio (SIR) plays important role in dark fermentation process to produce renewable energy of hydrogen fuel.","PeriodicalId":39007,"journal":{"name":"Malaysian Journal of Analytical Sciences","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67647272","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 : 2019-01-01DOI: 10.17576/mjas-2019-2301-16
Malaysian Journal, Ketahanan Pencilan Bakteria, Asli daripada Enapcemar Teraktif, T. Mangan, Nuratiqah Marsidi, M. Halmi, S. R. Abdullah
A study was conducted to observe the resistance of native isolated bacteria towards selected heavy metals (iron; Fe and manganese; Mn) in a separate exposure. Isolated bacteria were evaluated by culturing them in nutrient broth medium that contained approximately 3 ×10 CFU/mL bacteria with different initial concentrations (0, 50, 100 and 200 mg/L). Result showed that a plate with bacterial growth indicated bacterial resistance, which was verified based on CFU/mL. At 0 mg/L, bacteria grew well on the plate with Fe and Mn. The bacterial number began to decrease at 50 and 100 mg/L for Fe and at 200 mg/L for Mn. Only a few colonies survived (isolate AM2) the toxicity of high Fe amount; the isolated bacteria almost showed no growth along the plate. AM2, AM3 and AM4 presented resistance to Mn until 200 mg/L, but not AM6. The bacteria showed no growth at 100 and 200 mg/L. Thus, the Fe and Mn concentrations that can be applied during acclimatisation ranged from 0 mg/L to 200 mg/L with isolated AM2 and AM4 for Fe and Mn removal.
{"title":"RESISTANCE OF NATIVE BACTERIA ISOLATED FROM ACTIVATED SLUDGE TOWARDS IRON AND MANGANESE","authors":"Malaysian Journal, Ketahanan Pencilan Bakteria, Asli daripada Enapcemar Teraktif, T. Mangan, Nuratiqah Marsidi, M. Halmi, S. R. Abdullah","doi":"10.17576/mjas-2019-2301-16","DOIUrl":"https://doi.org/10.17576/mjas-2019-2301-16","url":null,"abstract":"A study was conducted to observe the resistance of native isolated bacteria towards selected heavy metals (iron; Fe and manganese; Mn) in a separate exposure. Isolated bacteria were evaluated by culturing them in nutrient broth medium that contained approximately 3 ×10 CFU/mL bacteria with different initial concentrations (0, 50, 100 and 200 mg/L). Result showed that a plate with bacterial growth indicated bacterial resistance, which was verified based on CFU/mL. At 0 mg/L, bacteria grew well on the plate with Fe and Mn. The bacterial number began to decrease at 50 and 100 mg/L for Fe and at 200 mg/L for Mn. Only a few colonies survived (isolate AM2) the toxicity of high Fe amount; the isolated bacteria almost showed no growth along the plate. AM2, AM3 and AM4 presented resistance to Mn until 200 mg/L, but not AM6. The bacteria showed no growth at 100 and 200 mg/L. Thus, the Fe and Mn concentrations that can be applied during acclimatisation ranged from 0 mg/L to 200 mg/L with isolated AM2 and AM4 for Fe and Mn removal.","PeriodicalId":39007,"journal":{"name":"Malaysian Journal of Analytical Sciences","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67647348","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 : 2019-01-01DOI: 10.17576/mjas-2019-2302-18
Azmah Hasran, S. Kamarudin, B. Majlis, W. Daud, A. Kadhum, G. Sugandi
Silicon electrode plates for micro fuel cells were obtained using a microfabrication process based on the micro-electromechanical system (MEMS) technology. The dry etching process involved the laser ablation technique using the highly stable Nd:YAG. This technique is suitable for micromachining silicon substrates. The total size of the electrode plate was 2.5 cm x 2.5 cm and the active reaction area was 1 cm. An increase in laser scan numbers deepened the groove being etched on the silicon sample, but it showed a saturated behavior as the number of scans became higher. The time required to etch a complete electrode plate flow field with 14 square-shaped through-holes of 0.185 cm x 0.185 cm area using laser ablation was ~30 minutes, which was much shorter than the wet etching time of more than 10 hours with the potassium hydroxide solution (KOH) solution. The laser-etched flow field achieved vertical sidewalls as per the original design, whereas the wet-etched structure achieved a typical anisotropic hole structure with sidewalls that were approximately 54o to the electrode surface due to the <100> orientation of the silicon wafer. Therefore, the laser ablation technique was chosen to produce the electrode plates for the micro fuel cell as it can save time on the etching process and produce more precise flow field dimensions for the electrode plates with less process steps compared with the conventional wet etching processes using KOH solution.
采用基于微机电系统(MEMS)技术的微加工工艺制备了微燃料电池用硅极板。干式蚀刻工艺采用高稳定性Nd:YAG的激光烧蚀技术。该技术适用于硅基板的微加工。电极板总尺寸为2.5 cm × 2.5 cm，活性反应面积为1 cm。随着激光扫描次数的增加，被蚀刻在硅样品上的凹槽加深，但随着扫描次数的增加，它表现出饱和行为。激光刻蚀面积为0.185 cm × 0.185 cm的14个方形通孔的完整电极板流场所需时间约为30分钟，大大缩短了氢氧化钾溶液(KOH)溶液10小时以上的湿法刻蚀时间。激光蚀刻流场按照原始设计实现了垂直的侧壁，而湿蚀刻结构实现了典型的各向异性孔结构，由于硅片的取向，侧壁与电极表面的距离约为54度。因此，选择激光烧蚀技术生产微型燃料电池极板，与传统的KOH溶液湿法蚀刻工艺相比，激光烧蚀技术可以节省蚀刻过程的时间，并且可以获得更精确的极板流场尺寸，而且工艺步骤更少。
{"title":"LASER-ASSISTED SILICON ETCHING FOR MICRO FUEL CELL ELECTRODE PLATE FABRICATION","authors":"Azmah Hasran, S. Kamarudin, B. Majlis, W. Daud, A. Kadhum, G. Sugandi","doi":"10.17576/mjas-2019-2302-18","DOIUrl":"https://doi.org/10.17576/mjas-2019-2302-18","url":null,"abstract":"Silicon electrode plates for micro fuel cells were obtained using a microfabrication process based on the micro-electromechanical system (MEMS) technology. The dry etching process involved the laser ablation technique using the highly stable Nd:YAG. This technique is suitable for micromachining silicon substrates. The total size of the electrode plate was 2.5 cm x 2.5 cm and the active reaction area was 1 cm. An increase in laser scan numbers deepened the groove being etched on the silicon sample, but it showed a saturated behavior as the number of scans became higher. The time required to etch a complete electrode plate flow field with 14 square-shaped through-holes of 0.185 cm x 0.185 cm area using laser ablation was ~30 minutes, which was much shorter than the wet etching time of more than 10 hours with the potassium hydroxide solution (KOH) solution. The laser-etched flow field achieved vertical sidewalls as per the original design, whereas the wet-etched structure achieved a typical anisotropic hole structure with sidewalls that were approximately 54o to the electrode surface due to the <100> orientation of the silicon wafer. Therefore, the laser ablation technique was chosen to produce the electrode plates for the micro fuel cell as it can save time on the etching process and produce more precise flow field dimensions for the electrode plates with less process steps compared with the conventional wet etching processes using KOH solution.","PeriodicalId":39007,"journal":{"name":"Malaysian Journal of Analytical Sciences","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67647542","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 : 2019-01-01DOI: 10.17576/mjas-2019-2301-05
N. Abdullah, S. Kamarudin, L. Shyuan
This study aims to develop a small size of TNF using an electrospinning process. TNF is applied in direct methanol fuel cell (DMFC) as a catalyst, catalyst support and a filler in the membrane. This study involves determining the parameters that affect the electrospinning process, particularly in terms of the distance between the needle tip and collector towards the size of TNF crystalline. The production of TNF involves an electrospinning process, followed by a stabilization and calcination process. Fourier Transformation Infrared (FTIR) analysis was carried out to analyse the purity of the samples, while X-ray diffractometer (XRD) analysis was carried out to determine the size of crystalline. The result demonstrates that the longer the distance between the needle and collector, the smaller the size of the TNF produced. A smaller sized crystalline offers a significant impact on catalytic reaction and overall performance of DMFC.
{"title":"PRODUCTION OF TITANIUM DIOXIDE NANOFIBER (TNF): INFLUENCE OF ELECTROSPINNING PARAMETER ON CRYSTALLINE SIZE","authors":"N. Abdullah, S. Kamarudin, L. Shyuan","doi":"10.17576/mjas-2019-2301-05","DOIUrl":"https://doi.org/10.17576/mjas-2019-2301-05","url":null,"abstract":"This study aims to develop a small size of TNF using an electrospinning process. TNF is applied in direct methanol fuel cell (DMFC) as a catalyst, catalyst support and a filler in the membrane. This study involves determining the parameters that affect the electrospinning process, particularly in terms of the distance between the needle tip and collector towards the size of TNF crystalline. The production of TNF involves an electrospinning process, followed by a stabilization and calcination process. Fourier Transformation Infrared (FTIR) analysis was carried out to analyse the purity of the samples, while X-ray diffractometer (XRD) analysis was carried out to determine the size of crystalline. The result demonstrates that the longer the distance between the needle and collector, the smaller the size of the TNF produced. A smaller sized crystalline offers a significant impact on catalytic reaction and overall performance of DMFC.","PeriodicalId":39007,"journal":{"name":"Malaysian Journal of Analytical Sciences","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67646838","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 : 2019-01-01DOI: 10.17576/mjas-2019-2303-17
Vita Nur Iftitahiyah, D. Prasetyoko, Hartati, Y. Ni'mah, H. Bahruji, Hadi Nur
The activity of zeolite HX acid catalyst synthesized from kaolin was investigated for esterification of acetic acid with benzyl alcohol. Zeolite HX was synthesized using kaolin minerals obtained from Bangka Belitung Sumatra, Indonesia via hydrothermal method and followed by cation exchange treatment. The conversion of acetic acid was driven by the presence of Brønsted acidity with the porosity plays a crucial role in determining product selectivity. The influence of reactants concentration, the effect of reaction time and the amount of catalyst loading were investigated to obtain optimum condition of the reaction. Zeolite HX catalyzed esterification of acetic acid to achieve 58.78% of conversion with increasing the concentrations of benzyl alcohol enhanced the conversion. The acetic acid esterification follows the Eley-Rideal mechanism with the conversion improved by prolonging the reaction time and increasing the amount of catalyst used in the system.
{"title":"ESTERIFICATION OF ACETIC ACID AND BENZYL ALCOHOL OVER ZEOLITE HX PRODUCED FROM BANGKA BELITUNG KAOLIN","authors":"Vita Nur Iftitahiyah, D. Prasetyoko, Hartati, Y. Ni'mah, H. Bahruji, Hadi Nur","doi":"10.17576/mjas-2019-2303-17","DOIUrl":"https://doi.org/10.17576/mjas-2019-2303-17","url":null,"abstract":"The activity of zeolite HX acid catalyst synthesized from kaolin was investigated for esterification of acetic acid with benzyl alcohol. Zeolite HX was synthesized using kaolin minerals obtained from Bangka Belitung Sumatra, Indonesia via hydrothermal method and followed by cation exchange treatment. The conversion of acetic acid was driven by the presence of Brønsted acidity with the porosity plays a crucial role in determining product selectivity. The influence of reactants concentration, the effect of reaction time and the amount of catalyst loading were investigated to obtain optimum condition of the reaction. Zeolite HX catalyzed esterification of acetic acid to achieve 58.78% of conversion with increasing the concentrations of benzyl alcohol enhanced the conversion. The acetic acid esterification follows the Eley-Rideal mechanism with the conversion improved by prolonging the reaction time and increasing the amount of catalyst used in the system.","PeriodicalId":39007,"journal":{"name":"Malaysian Journal of Analytical Sciences","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67647355","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 : 2019-01-01DOI: 10.17576/mjas-2019-2301-07
S. Malek, Y. Mohd
Platinum (Pt) films were prepared on Titanium (Ti) surface at various deposition times ranging from 30 to 90 minutes using the electrodeposition technique. The morphology of the Pt films was determined using field emission scanning electron microscope (FESEM). Furthermore, the electrocatalytic activity of the prepared Pt films towards methanol oxidation in alkaline medium was investigated using cyclic voltammetry. The surface morphology changed with different deposition times from less compact durian-like structure at shorter times (< 60 minutes) to more compact durian-like structure at longer times (> 60 minutes). The loading amount and surface coverage of Pt on the Ti surface were increased as the deposition time increased. The calculated values of electrochemically active surface area (ECSA) for the Pt films were increased with increasing deposition time as evident in 30 minutes (6.54 m g), 45 minutes (7.34 m g) and 60 minutes (8.08 m g). Nevertheless, the ECSA value dropped to 7.70 m g for longer deposition time (90 minutes). This may be caused by the coagulation of the Pt centres with the growth of neighbouring centres, which decreasing the available active surface area on the films. This film also demonstrated the highest stability for methanol oxidation reaction (MOR) in alkaline medium with the result of 5.18 mA cm at 1 hour.
采用电沉积技术，在30 ~ 90分钟的不同沉积时间下，在钛(Ti)表面制备了铂(Pt)薄膜。用场发射扫描电子显微镜(FESEM)观察了Pt薄膜的形貌。此外，用循环伏安法研究了制备的Pt膜在碱性介质中对甲醇氧化的电催化活性。随着沉积时间的不同，表面形貌发生了变化，从较短时间(< 60分钟)较不致密的榴莲状结构到较长时间(60分钟)较致密的榴莲状结构。随着沉积时间的延长，Pt在Ti表面的负荷量和表面覆盖率均有所增加。Pt薄膜的电化学活性表面积(ECSA)计算值随着沉积时间的增加而增加，分别为30分钟(6.54 m g)、45分钟(7.34 m g)和60分钟(8.08 m g)，但随着沉积时间的延长(90分钟)，ECSA值下降到7.70 m g。这可能是由于铂中心与邻近中心的生长发生混凝，从而减少了薄膜上的有效表面积。该膜在碱性介质中甲醇氧化反应(MOR)的稳定性最高，1小时的稳定性为5.18 mA cm。
{"title":"EFFECT OF DEPOSITION TIME ON STRUCTURAL AND CATALYTIC PROPERTIES OF Pt FILMS ELECTRODEPOSITED ON Ti SUBSTRATE","authors":"S. Malek, Y. Mohd","doi":"10.17576/mjas-2019-2301-07","DOIUrl":"https://doi.org/10.17576/mjas-2019-2301-07","url":null,"abstract":"Platinum (Pt) films were prepared on Titanium (Ti) surface at various deposition times ranging from 30 to 90 minutes using the electrodeposition technique. The morphology of the Pt films was determined using field emission scanning electron microscope (FESEM). Furthermore, the electrocatalytic activity of the prepared Pt films towards methanol oxidation in alkaline medium was investigated using cyclic voltammetry. The surface morphology changed with different deposition times from less compact durian-like structure at shorter times (< 60 minutes) to more compact durian-like structure at longer times (> 60 minutes). The loading amount and surface coverage of Pt on the Ti surface were increased as the deposition time increased. The calculated values of electrochemically active surface area (ECSA) for the Pt films were increased with increasing deposition time as evident in 30 minutes (6.54 m g), 45 minutes (7.34 m g) and 60 minutes (8.08 m g). Nevertheless, the ECSA value dropped to 7.70 m g for longer deposition time (90 minutes). This may be caused by the coagulation of the Pt centres with the growth of neighbouring centres, which decreasing the available active surface area on the films. This film also demonstrated the highest stability for methanol oxidation reaction (MOR) in alkaline medium with the result of 5.18 mA cm at 1 hour.","PeriodicalId":39007,"journal":{"name":"Malaysian Journal of Analytical Sciences","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"67646977","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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