Oman Zuas
Research Centre for Chemistry, Indonesian Institute of Science (RCChem-LIPI), Kawasan PUSPIPTEK Serpong, 15314 Tangerang, Banten

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FLOW RATE OF CARRIER GAS AFFECTING THE KEY PARAMETERS OF GC-TCD FOR CO2, C3H8, AND CO ANALYSIS: AN EXPERIMENTAL INVESTIGATION Zuas, Oman; Budiman, Harry
Teknologi Indonesia Vol 39, No 2 (2016)
Publisher : LIPI Press

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14203/jti.v39i2.240

Abstract

This paper reports on the effect of flow rate of helium (He) carrier gas on the key parameters of gas chromatography equipped with thermal conductivity detector (GC-TCD) for the measurement of carbon dioxide (CO2 ), propane (C3H8) and carbon monoxide (CO) in gravimetric standard gas mixture (Grav-SGM). The carrier gas has a function to transport vaporized molecules through the column during the GC separation process. The study provides opportunity to experimentally investigate the effect of gas flow rate on the several key parameters of the GC-TCD including retention time, peak area, peak height, response factor, resolution and selectivity. The results show that all key parameters were found to be carrier gas flow rate dependent. The increase of the gas flow rate could significantly decrease the retention time, peak area and response factor of the gas components. While both resolution and selectivity factor were observed to have a substantial decrease with increasing the flow rate of carrier gas. Therefore, proper selection of flow rate level of carrier gas is suggested before a GC measurement is carried out for obtaining an optimum condition.
SIMULTANEOUS MEASUREMENT OF SYN-GAS COMPONENT (H2, CO2, CH4, AND CO) AS PRODUCT OF BIOMASS GASIFICATION BY USING VALIDATED GC-TCD METHOD Mulyana, Muhammad Rizky; Zuas, Oman; Budiman, Harry; Simanungkalit, Sabar; Rinaldi, Nino
Scientific Contributions Oil and Gas Vol 41, No 1 (2018)
Publisher : Scientific Contributions Oil and Gas

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.29017/SCOG.41.1.73

Abstract

Biomass gasification has been widely known method to produce syn-gases, which can be considered as great alternative substitution for fossil fuels. However, accurate verification of the syn-gas composition requires a reliable and validated method for simultaneous measurement of H2, CO2, CH4, and CO. In order to fulfill the aforementioned requirements, which is the objective of this study; a GC-TCD method for simultaneous measurement of H2, CO2, CH4, and CO component in syn-gas has been validated in accordance to ISO/IEC 17025 and its application for real samples. For the method validation purpose, all of the performance parameters were evaluated and discussed in detail in this study. Intraday precision and interday precision were found to be acceptable having the %RSD below 0.67xCV Horwitz and below 1.0xCV Horwitz, respectively. The bias value falls within +2σ for entire components, indicating that the method accuracy can be accepted. Coefficient correlation for all components was higher than 0.99, which means that the method has suffi cient linearity. LoD and LoQ for each component were found to be lower than typical syn-gas concentration range. The method roughness was also found in an acceptable level (the p-values was higher than 0.05 for allctarget components. Application of the validated method for the measurement of a real syn-gas samples indicated that the method is quite reliable to produce an accurate data and the validated methid can be used in a routine analysis. The innovation of this study, as shown by experiment results, is to evaluate the validated method’s performance for simultaneous determination of syn-gas components’ concentration in one channel, compared to common method in which the syn-gas components were measured separatedly in a different channel.Biomass gasifi cation has been widely known method to produce syn-gases, which can be consideredas great alternative substitution for fossil fuels. However, accurate verifi cation of the syn-gas compositionrequires a reliable and validated method for simultaneous measurement of H2, CO2, CH4, and CO. Inorder to fulfi ll the aforementioned requirements, which is the objective of this study; a GC-TCD methodfor simultaneous measurement of H2, CO2, CH4, and CO component in syn-gas has been validated inaccordance to ISO/IEC 17025 and its application for real samples. For the method validation purpose,all of the performance parameters were evaluated and discussed in detail in this study. Intraday precisionand interday precision were found to be acceptable having the %RSD below 0.67xCV Horwitz and below1.0xCV Horwitz, respectively. The bias value falls within +2σ for entire components, indicating that themethod accuracy can be accepted. Coeffi cient correlation for all components was higher than 0.99, whichmeans that the method has suffi cient linearity. LoD and LoQ for each component were found to be lowerthan typical syn-gas concentration range. The method roughness was also found in an acceptable level(the p-values was higher than 0.05 for allctarget components. Application of the validated method for themeasurement of a real syn-gas samples indicated that the method is quite reliable to produce an accuratedata and the validated methid can be used in a routine analysis. The innovation of this study, as shown byexperiment results, is to evaluate the validated method’s performance for simultaneous determination ofsyn-gas components’ concentration in one channel, compared to common method in which the syn-gascomponents were measured separatedly in a different channel.Keywords: syn-gas, GC-TCD, method validation.
Extraction of Chemical Warfare Agents from Soils: Case Study on O-ethyl S-2-(diisopropylamino)ethyl methylphosphonothiolate (VX) Zuas, Oman
Jurnal Natur Indonesia Vol 11, No 1 (2008)
Publisher : Lembaga Penelitian dan Pengabdian kepada Masyarakat Universitas Riau

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (109.556 KB) | DOI: 10.31258/jnat.11.1.1-7

Abstract

Extraction of chemical warfare agents, O-ethyl S-2-(diisopropylamino)ethyl methylphosphonothiolate (VX) in soilsample has been carried out. The extraction was performed using six different solvents including 1% TEA/MeOH,1% NH4OH/MeOH, water pH 2 at the ambient temperature , water pH 2 at temperature 4 0C, water pH 7 at ambienttemperature, and water pH 7 at temperature 4 0C. Percent recovery of VX in soil samples was quantitativelydetermined by mean LC-MS using selected reaction monitoring (SRM). Among the solvents used, water pH 2 attemperature 40C gave the best extraction capability that was indicated by the highest percent recovery of VXobtained. Storing effect of spiked samples was also investigated by extracting the samples containing VX usingwater at pH 2/40C and the degradation product was then identified using multiple reaction monitoring (MRM). Fromthe study, two degradation products were identified as Bis[2-(diisopropylamino)ethyl]disulphide and ethylmethylphosphonate.