Claim Missing Document
Check
Articles

Utilizing of alkybenzene homologous series on the determination of kovats retention index in the RP-HPLC using methanol/water solvent system Idroes, Rinaldi
Indonesian Journal of Pharmacy Vol 20 No 2, 2009
Publisher : Faculty of Pharmacy Universitas Gadjah Mada, Yogyakarta, Skip Utara, 55281, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (197.285 KB) | DOI: 10.14499/indonesianjpharm0iss0pp77-83

Abstract

Retention times in high performance liquid chromatography are very susceptible to small changes of the stationary phase, temperature, pH-value, mobile-phase composition and flow rate. One of the methods to minimize these effects is by utilizing a retention index system. In contrast to GC, the retention Index determination method in HPLC is still widely discussed, because of difficulty utilizing n-alkane as standard. In addition, the solutes in HPLC interact with the mobile-phase, thus the retention data also depend on the mobilephase. It is not easy to use n-alkane in HPLC as standards because of considerable problems. Due to their very non polar properties, hence in most reversed phase systems, they show large retention times. Therefore, using nalkane in routine analysis could be inconvenient. In comparison with n-alkane, the alkylbenzene homologous series are stable compound and commercially available. They have a high UV absorbance at the wavelength of 254 nm, and thus are easily detected by a UV detector. This paper will introduce Kovats Retention Index Determination in the HPLC by using alkylbenzene homologous series and then is to be connected with n-alkane as a frame of reference. Steroids were used as test substance for determining Kovats retention index values in methanol/ water system.Key words: RP-HPLC, Kovats Retention Index, n-Alkane, Alkyl Benzene.
Dead time determination and its influence to retention index in GC system using polar capillary column Idroes, Rinaldi; Oesman, Frida
Indonesian Journal of Pharmacy Vol 22 No 3, 2011
Publisher : Faculty of Pharmacy Universitas Gadjah Mada, Yogyakarta, Skip Utara, 55281, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (228.696 KB) | DOI: 10.14499/indonesianjpharm0iss0pp257-264

Abstract

In this research for the determination of dead timeused a method that is mathematically calculated as iteration and linearization of the polar capillarry column  in  Gas  Chromatography  (GC)  type  DN-Wax,  by  injecting  the  homologous series  of  n-alkanes  (n-pentane  up  to  n-decane)  on  GC  system.  The  dead  time values  obtained  are  then  used  to  determine  the  Kovats  Retention  Index (Retention  Index,  RI).  The  results indicated that the  retention index  had  values of  systematic  error  those  are  more  accurate  than  the  retention  time  (tR), corrected retention time (tR') and retention factor(k'), but the retention index shows  the  value  of  random  error  slightly  larger  than  with  other  retention parameters. In this study  the average values obtained by the iteration method, the  dead  time  was  3.52  minutes  with  a  correlation  coefficient  of  0.9998.Retention  index  values  obtained  are  at  the  confidence  level  92.11%-97.06% with the systematic errors 2.04%-7.89%, while the linearization method showed the average value of the dead time 3.3 minutes witha correlation coefficient of 0.9992,  but  the  value  of  retention  index  values  obtained  show  that  the systematic error is very large.Key words:Dead time, Retention Index, Homologous Series, GC
Evaluation of chromatographic dead times for retention indices determination in RP-HPLC using some homologous series Rinaldi Idroes
Indonesian Journal of Pharmacy Vol 20 No 3, 2009
Publisher : Faculty of Pharmacy Universitas Gadjah Mada, Yogyakarta, Skip Utara, 55281, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (174.317 KB) | DOI: 10.14499/indonesianjpharm0iss0pp133-140

Abstract

Dead time that defined as a retention time of unretained substance in the chromatographic coloumn, is needed to determine all retention parameters in coloumn chromatography such as corrected retention time, relative retention time and Kovats Retention Indices.This research reported a comparison between the iteration and linearization of corrected retention times of homologous series such as n-alkane, akylrylketone, alkylbenzene and 2-alkanone. Furthermore the iteration method provides better dead-time values and smaller standard deviations than the linearization method. Moreover, the dead-time calculation obtained according to homologous series is not depending on solvent composition for various homologous series.The n-alkane homologous series show better indication accuracy of fit (S/N) in comparison with other homologous series, thereafter 2-alkanone exhibit the second best adjustment.Keywords: Dead-time evaluation, homologous series, methanol/water solvent, RP-HPLC.
Evaluation of chromatographic dead times for retention indices determination in RP-HPLC using some homologous series Rinaldi Idroes
Indonesian Journal of Pharmacy Vol 20 No 3, 2009
Publisher : Faculty of Pharmacy Universitas Gadjah Mada, Yogyakarta, Skip Utara, 55281, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (174.317 KB) | DOI: 10.14499/indonesianjpharm0iss0pp133-140

Abstract

Dead time that defined as a retention time of unretained substance in the chromatographic coloumn, is needed to determine all retention parameters in coloumn chromatography such as corrected retention time, relative retention time and Kovats Retention Indices.This research reported a comparison between the iteration and linearization of corrected retention times of homologous series such as n-alkane, akylrylketone, alkylbenzene and 2-alkanone. Furthermore the iteration method provides better dead-time values and smaller standard deviations than the linearization method. Moreover, the dead-time calculation obtained according to homologous series is not depending on solvent composition for various homologous series.The n-alkane homologous series show better indication accuracy of fit (S/N) in comparison with other homologous series, thereafter 2-alkanone exhibit the second best adjustment.Keywords: Dead-time evaluation, homologous series, methanol/water solvent, RP-HPLC.
Utilizing of alkybenzene homologous series on the determination of kovats retention index in the RP-HPLC using methanol/water solvent system Rinaldi Idroes
Indonesian Journal of Pharmacy Vol 20 No 2, 2009
Publisher : Faculty of Pharmacy Universitas Gadjah Mada, Yogyakarta, Skip Utara, 55281, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14499/indonesianjpharm0iss0pp77-83

Abstract

Retention times in high performance liquid chromatography are very susceptible to small changes of the stationary phase, temperature, pH-value, mobile-phase composition and flow rate. One of the methods to minimize theseeffects is by utilizing a retention index system. In contrast to GC, the retention Index determination method in HPLC is still widely discussed, because of difficulty utilizing n-alkane as standard. In addition, the solutes in HPLC interact with the mobile-phase, thus the retention data also depend on the mobilephase. It is not easy to use n-alkane in HPLC as standards because of considerable problems. Due to their very non polar properties, hence in most reversed phase systems, they show large retention times. Therefore, using nalkane in routine analysis could be inconvenient. In comparison with n-alkane, the alkylbenzene homologous series are stable compound and commercially available. They have a high UV absorbance at the wavelength of 254 nm, and thus are easily detected by a UV detector. This paper will introduce Kovats Retention Index Determination in the HPLC by using alkylbenzene homologous series and then is to be connected with n-alkane as a frame of reference. Steroids were used as test substance for determining Kovats retention index values in methanol/ water system.Key words: RP-HPLC, Kovats Retention Index, n-Alkane, Alkyl Benzene.
Hydrogen Desorption Properties of MgH2 + 10 wt% SiO2 + 5 wt% Ni Prepared by Planetary Ball Milling Malahayati Malahayati; Evi Yufita; Ismail Ismail; Mursal Mursal; Rinaldi Idroes; Zulkarnain Jalil
Bulletin of Chemical Reaction Engineering & Catalysis 2021: BCREC Volume 16 Issue 2 Year 2021 (June 2021)
Publisher : Department of Chemical Engineering - Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.16.2.10220.280-285

Abstract

MgH2 is a very hopeful material for application as hydrogen storage material in the solid form. This is due to its reversibility and its ability to store large amounts of hydrogen, which is 7.6 wt%. However, this material still has weaknesses, namely high operating temperature and slow kinetic reactions. Various attempts have been made to overcome this weakness, including downsizing and adding catalyst. In this study, double catalyst was used, namely natural silica extracted from rice husk ash and nickel nano powder, with a composition of MgH2 + 10 wt% SiO2 + 5 wt% Ni. The purpose of this research was to study the effect of downsizing and using these catalysts to the thermodynamic and kinetic properties of the hydrogen storage material MgH2. Samples were prepared by using High Energy Ball Milling (HEBM), with variations in milling time of 1, 5, 10, and 15 hours. The X-ray Diffraction (XRD) pattern showed the presence of an impurity phase in the samples milled for 10 and 15 hours. It also showed a reduction in grain size with increasing milling time. However, agglomeration has occurred in the samples milled for 15 hours. From the Scanning Electron Microscope (SEM) results can be seen that the sample with longer milling time, were homogeneously distribute. Thermal investigation showed that the lowest desorption temperature was achieved in samples with milling time of 5 and 10 hours, namely 287 °C and 288 °C. This study shows that natural silica catalyst plays a role in improving the thermodynamic characteristics of MgH2, while Ni plays a role in improving the kinetic characteristics of MgH2. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0). 
ALKYLARYLKETONE HOMOLOGOUS SERIES FOR DETERMINATION OF KOVATS RETENTION INDICES WITH RP-HPLC USING ACETONITRILE/WATER SYSTEM Rinaldi Idroes
Indonesian Journal of Chemistry Vol 10, No 1 (2010)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (279.74 KB) | DOI: 10.22146/ijc.21480

Abstract

Some factors such as the changes of the stationary phase, temperature, pH-value, mobile-phase composition and flow rate play a crucial role in effecting the sensitivity of retention times in high performance liquid chromatography (HPLC) system. Utilizing a retention index system is one of the methods to minimize those effects. Besides the mentioned factors, dead-time influences on determining the retention index as well. In comparison with Gas Chromatography (GC), the retention Index determination method in HPLC is still widely discussed, due to the difficulty of utilizing n-alkane as standard. In addition, the solutes in HPLC interact with the mobile-phase, thus the retention behavior also depend on the mobile-phase. Actually, It is difficult to use n-alkanes in HPLC as standards in case of some considerable problems, due to they are very non polar but also large retention times which lack of chromophores. Therefore, using n-alkane in routine analysis could be inconvenient. In comparison with n-alkanes, the alkylarylketones homologous series are stable compounds, commercially available and easily detected by a UV detector. This paper introduces Determination of Kovats Retention Index in the HPLC using Alkylarylketone homologous series and then is connected with n-alkane as a frame of reference. Steroids were used as test substance for calculating Kovats retention index values in acetonitrile/water system.
Distribution pattern of Pb and Zn contamination in rivers near industrial zone in Aceh, Indonesia, revealed by principal component analysis (PCA) Lelifajri Lelifajri; Rahmadi Rahmadi; Rinaldi Idroes; Supriatno Supriatno; Eka Safitri; Nazaruddin Nazaruddin; Ilham Maulana; Khairi Suhud
Jurnal Rekayasa Kimia & Lingkungan Vol 17, No 1 (2022): Jurnal Rekayasa Kimia dan Lingkungan (January-June, 2022)
Publisher : Chemical Engineering Department, Syiah Kuala University, Banda Aceh, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (314.297 KB) | DOI: 10.23955/rkl.v17i1.22672

Abstract

The research aims to evaluate the pollution of Pb and Zn in water, sediment, and Faunus ater samples collected from Krueng Balee (KB) and Kreung Reuleung (KR) Rivers, Aceh, Indonesia. The samples were collected at the upstream, midstream, and downstream of each river and analyzed using Atomic Absorption Spectrophotometry (AAS). The distribution of Pb and Zn pollution was analyzed using Principal Component Analysis (PCA). Our investigation revealed that the presence of Pb and Zn is still safe for water and sediment samples. Nevertheless, Pb and Zn contamination found in F. ater samples had exceeded the national safety limit for food. PCA analysis revealed correlations between samples suggesting the roles of physical and chemical properties of the river in the pollutant retainment. The analysis also indicated the possible antagonism between Pb and Zn accumulation in F. ater which has never been reported previously. We suggest routine monitoring of Pb and Zn concentrations. The role of the surrounding industry in the Pb and Zn pollution should be further studied.
PENENTUAN WAKTU MATI MEMANFAATKAN DERET HOMOLOG ALKILPARABEN PADA RP-HPLC DALAM SISTEM PELARUT METANOL/AIR Mahmudi .; Saiful .; Khairan .; Rinaldi Idroes
Jurnal Natural Volume 15, Number 2, September 2015
Publisher : Universitas Syiah Kuala

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (203.052 KB)

Abstract

Penelitian ini dalam rangka pengembangan dan aplikasi metode penentuan waktu mati (t0) pada Kromatografi Cair dari yang telah pernah dan berhasil diterapkan di GC. Waktu mati merupakan parameter yang sangat penting untuk penentuan parameter lain seperti Faktor kapasitas (k’), retensi relative (tR’) dan indeks retensi kovats (IR), sehingga didapat hasil berupa data base yang bisa diterapkan dalam intrumentasi GC dan RP-HPLC. Penentuan waktu mati dengan menggunakan dua metode yaitu metode iterasi dan metode linearisasi, sehingga didapat nilai indeks retensi kovats dari senyawa uji pada sistem RP-HPLC dengan menggunakan deret homolog alkilparaben. Hasil penelitian menunjukkan deret homolog alkilparaban terbukti dapat digunakan untuk penentuan indeks retensi Kovats  dalam RP-HPLC dengan koefisien korelasi yang sangat baik  terutama pada sistem pelarut MeHO/H2O (90:10). 
PENGARUH KOMBINASI EKSTRAK PETROLEUM ETER BAWANG PUTIH (Allium sativum Linn) DENGAN VITAMIN C TERHADAP AKTIVITAS Candida albicans Nurul Khaira; Misrahanum Misrahanum; Rinaldi Idroes; Muhammad Bahi; Khairan Khairan
Jurnal Natural Volume 16, Number 1, March 2016
Publisher : Universitas Syiah Kuala

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (170.59 KB) | DOI: 10.24815/jn.v16i1.4725

Abstract

Garlic (Allium sativum) contains organosulfur compound that plays an important role as an antibacterial and antifungal activities. Ascorbic acid or vitamine C also has been show has a good activity as an antioxidant and as an antifungal. The aims of the research is to determine the effect of the combination of petroleum ether garlic extract with vitamin C against Candida albicans. Zone of inhibition testing done by Kirby-Bauer method. The results showed that the combination of petroleum ether garlic extract with vitamin C in concentration of 50% did not show an activity significantly. Meanwhile, the activity of petroleum ether garlic extract alone at concentration of 50 and 75% showed activities towards Candida albicans with a diameter of inhibition zone are 19.46 and 27.46 mm respectively. 
Co-Authors Abdelrahman O. Ezzat Abdul Hawil Abas Aga Maulana Agus Munawar Agus Winarsih Andi Lala Azharuddin Azharuddin Boy M. Bachtiar Claus Jacob Claus Jacob Claus Jacob Diana S. Ningsih Diana Setya Ningsih Dimas Rendy Sugara Edi Saputra Ringga EKA SAFITRI Eka Safitri Elisa Purwaendah Elly Sufriadi Erisna Mirda Erkata Yandri Ethiene Castellucci Estevam Evi Yufita Faradilla Faradilla Farassa Rani Faisal Farnida Farnida Fatimawali Fatimawali Fazlin Mohd Fauzi Firaihanil Jannah Fitranto Kusumo Ghalieb Mutig Idroes Ghalieb Mutig Idroes Ghalieb Mutig Idroes Ghazi M. Idroes Ghazi Mauer Idroes Hesti Meilina Iin Shabrina Hilal Ilham Maulana Ira Maya Irsan Hardi Irvanizam Irvanizam Ismail Ismail Isra Firmansyah Justinus Satrio Karl Herbert Schaefer Khairan . Khairan Khairan Khairan Khairan Khairan Khairan Khairan Khairan Khairan Khairan Khairan Khairan Khairan Khairan Khairan Khairan KHAIRI SUHUD Khairi Suhud Khalijah Awang Lelifajri Lelifajri Lensoni Mahmudi . Mahmudi Mahmudi Malahayati Malahayati Maria Paristiowati Misrahanum Misrahanum Mohamed El-Shazly Mohsina Patwekar Muhammad Bahi Muhammad Bahi Muhammad Bahi Muhammad Diah Muhammad Diah Muhammad Subianto Muhammad Yusuf Muliadi Ramli Murniana Murniana Mursal Mursal Musfira Arini Muslem Muslem Nanda Earlia Nanda Earlia Nasrullah Idris NAZARUDDIN NAZARUDDIN Nazaruddin Nazaruddin Nor Diyana Md Sani Novi Reandy Sasmita Novi Reandy Sasmita Novi Reandy Sasmita Noviana Husdayanti Nur B. Maulydia Nur Balqis Maulydia Nurdjannah Jane Niode Nurleila Nurleila Nurul Khaira Oesman, Frida Pati Kemala Pati Kemala Qurrata Akyuni Rahmadi Rahmadi Raihan Raihan Raihan Raihan Raudhatul Jannah Razief Perucha Fauzie Afidh Rivansyah Suhendra Rivansyah Suhendra Rizka Auliatul Jannah Rusdi Andid Saiful . Saiful Saiful Saiful Saiful Sarah Ika Nainggolan Souvia Rahimah Sufriani Sufriani Sunarti Abd Rahman Supriatno Supriatno Suryadi Suryadi Talha Bin Emran Tatsa Rizkia Taufik Ridwan Teuku Rizky Noviandy Teuku Zhilalmuhana Thomas Schneider Trina E. Tallei Trina Ekawati Tallei Trina Ekawati Tallei Tuti Fadlilah Utari Zulfiani Waliam Mursyida Zahriah Zahriah Zuchra Helwani Zuchra Helwani Zulkarnain Jalil Zulkarnain Jalil