Displaying publications 1 - 20 of 345 in total

  1. Man CN, Noor NM, Harn GL, Lajis R, Mohamad S
    J Chromatogr A, 2010 Nov 19;1217(47):7455-9.
    PMID: 20950812 DOI: 10.1016/j.chroma.2010.09.064
    Tetrodotoxin (TTX), a toxic compound found in some puffers can cause death to humans through consumption. We have developed a simplified method for the screening of TTX in puffers using GC-MS. A puffer tissue of 0.5g was treated with 5mL of 0.1% acetic acid, followed by alkaline hydrolysis, LLE or liquid-liquid extraction and N-methyl-N-TMS-trifluoroacetamide derivatization. The developed method used only a small sample and solvent, simplified LLE and derivatization procedures and short chromatographic analysis (8.2min). All of these contribute to cost-saving, enhanced sample throughput and high sensitivity of the screening assay. The developed method was validated and proved to be within the acceptable range.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry/economics; Gas Chromatography-Mass Spectrometry/methods*
  2. Reddy AVB, Yusop Z, Jaafar J, Bin Aris A, Abdul Majid Z
    J Sep Sci, 2017 Aug;40(15):3086-3093.
    PMID: 28581679 DOI: 10.1002/jssc.201700252
    An extremely sensitive and simple gas chromatography with mass spectrometry method was developed and completely validated for the analysis of five process-related impurities, viz., 4-hydroxy-l-phenylglycine, 4-hydroxyphenylacetonitrile, 4-hydroxyphenylacetic acid, methyl-4-hydroxyphenylacetate, and 2-[4-{(2RS)-2-hydroxy-3-[(1-methylethyl)amino]propoxy}phenyl]acetonitrile, in atenolol. The separation of impurities was accomplished on a BPX-5 column with dimensions of 50 m × 0.25 mm i.d. and 0.25 μm film thickness. The method validation was performed following International Conference on Harmonisation guidelines in which the method was capable to quantitate 4-hydroxy-l-phenylglycine, 4-hydroxyphenylacetonitrile, and 4-hydroxyphenylacetic acid at 0.3 ppm, and methyl-4-hydroxyphenylacetate and 2-[4-{(2RS)-2-hydroxy-3-[(1-methylethyl)amino]propoxy}phenyl]acetonitrile at 0.35 ppm with respect to 10 mg/mL of atenolol. The method was linear over the concentration range of 0.3-10 ppm for 4-hydroxy-l-phenylglycine, 4-hydroxyphenylacetonitrile, and 4-hydroxyphenylacetic acid, and 0.35-10 ppm for methyl-4-hydroxyphenylacetate and 2-[4-{(2RS)-2-hydroxy-3-[(1-methylethyl)amino]propoxy}phenyl]acetonitrile. The correlation coefficient in each case was found ≥0.998. The repeatability and recovery values were acceptable, and found between 89.38% and 105.60% for all five impurities under optimized operating conditions. The method developed here is simple, selective, and sensitive with apparently better resolution than the reported methods. Hence, the method is a straightforward and good quality control tool for the quantitation of selected impurities at trace concentrations in atenolol.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry*
  3. Juahir H, Ismail A, Mohamed SB, Toriman ME, Kassim AM, Zain SM, et al.
    Mar Pollut Bull, 2017 Jul 15;120(1-2):322-332.
    PMID: 28535957 DOI: 10.1016/j.marpolbul.2017.04.032
    This study involves the use of quality engineering in oil spill classification based on oil spill fingerprinting from GC-FID and GC-MS employing the six-sigma approach. The oil spills are recovered from various water areas of Peninsular Malaysia and Sabah (East Malaysia). The study approach used six sigma methodologies that effectively serve as the problem solving in oil classification extracted from the complex mixtures of oil spilled dataset. The analysis of six sigma link with the quality engineering improved the organizational performance to achieve its objectivity of the environmental forensics. The study reveals that oil spills are discriminated into four groups' viz. diesel, hydrocarbon fuel oil (HFO), mixture oil lubricant and fuel oil (MOLFO) and waste oil (WO) according to the similarity of the intrinsic chemical properties. Through the validation, it confirmed that four discriminant component, diesel, hydrocarbon fuel oil (HFO), mixture oil lubricant and fuel oil (MOLFO) and waste oil (WO) dominate the oil types with a total variance of 99.51% with ANOVA giving Fstat>Fcritical at 95% confidence level and a Chi Square goodness test of 74.87. Results obtained from this study reveals that by employing six-sigma approach in a data-driven problem such as in the case of oil spill classification, good decision making can be expedited.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry*
  4. Masni Mohd Ali, Norfariza Humrawali, Mohd Talib Latif
    Kajian ini adalah mengenai peranan sterol sebagai penunjuk bio-lipid untuk mengenal pasti variasi dan sumber bahan organik yang hadir bersama sedimen permukaan dari Kuala Selangor, Selangor. Kajian melibatkan kaedah pengekstrakan sterol daripada sampel sedimen dan seterusnya dianalisis menggunakan GC-MS untuk menentukan kehadiran sebatian tersebut. Sepuluh sebatian sterol dikenal pasti hadir dengan fitosterol merupakan sebatian dominan di kawasan kajian iaitu 79% daripada jumlah keseluruhan sterol. Ini diikuti oleh kolesterol serta sterol kumbahan masing-masing menyumbangkan 6% daripada jumlah keseluruhan sterol manakala selebihnya berada dalam julat 1-5%. Indeks Sumber Sterol (SSI) juga menunjukkan kandungan fitosterol yang tinggi walaupun hadir pada kadar yang berbeza di setiap stesen pensampelan. Penilaian pencemaran kumbahan menggunakan nisbah koprostanol/kolesterol, koprostanol/(koprostanol+kholestanol) serta epikoprostanol/koprostanol menunjukkan kawasan kajian tidak mengalami pencemaran kumbahan walaupun sterol daripada sumber kumbahan hadir di persekitarannya. Kesimpulannya sedimen permukaan di Kuala Selangor, Selangor mengandungi campuran sterol daripada pelbagai sumber yang hadir di persekitarannya dengan didominasi oleh fitosterol yang berasal daripada tumbuhan terestrial.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  5. Idris NF, Le-Minh N, Hayes JE, Stuetz RM
    J Environ Manage, 2022 Mar 01;305:114426.
    PMID: 34998062 DOI: 10.1016/j.jenvman.2021.114426
    Poor performance of wet scrubbers in rubber processing plants due to breakthrough of specific volatile organic compounds (VOCs) causes odour impact events. The performance of wet scrubbers in the rubber drying process to remove VOCs was investigated in order to determine the responsible odorants. VOC emissions originating at the inlet and outlet of wet scrubbers were quantified using gas chromatography-mass spectrometry/olfactometry (GC-MS/O). Critical VOCs were identified alongside seasonal and daily variations of those VOCs. Altogether, 80 VOCs were detected in rubber emissions with 16 classified as critical VOCs based on their chemical concentration, high odour activity value (OAV) and unpleasant odour. Volatile fatty acids (VFAs) were the dominant VOCs with seasonal variations affecting emission composition. Results demonstrated the ineffectiveness of the wet scrubbers to mitigate odorous VOCs whereas the removal of some VOCs could be improved based on their polarity and solubility. It was found that there is a correlation between the wet scrubber performance and VFAs concentration in the emissions. The findings demonstrated that combining quantitative and sensory analyses improved accuracy in identifying odorous VOCs, which can cause odour annoyance from rubber processing. A VOC identification framework was proposed using both analyses approaches.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  6. Tan YL, Abdullah AZ, Hameed BH
    Bioresour Technol, 2017 Nov;243:85-92.
    PMID: 28651142 DOI: 10.1016/j.biortech.2017.06.015
    Durian shell (DS) was pyrolyzed in a drop-type fixed-bed reactor to study the physicochemical properties of the products. The experiment was carried out with different particle sizes (up to 5mm) and reaction temperatures (250-650°C). The highest bio-oil yield was obtained at 650°C (57.45wt%) with DS size of 1-2mm. The elemental composition and higher heating value of the feedstock, bio-oil (650°C), and bio-char (650°C) were determined and compared. The compositions of product gases were determined via gas chromatography with thermal conductivity detector. The chemical composition of bio-oil was analyzed by gas chromatography-mass spectrometry. The bio-oil produced at lower temperature yields more alcohols, whereas the bio-oil produced at higher temperature contains more aromatics and carbonyls. Bio-oil has potential to be used as liquid fuel or fine chemical precursor after further upgrading. The results further showed the potential of bio-char as a solid fuel.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  7. Serag A, Zayed A, Mediani A, Farag MA
    Sci Rep, 2023 Feb 13;13(1):2533.
    PMID: 36781893 DOI: 10.1038/s41598-023-28551-x
    Tongkat ali commonly known as Malaysian Ginseng (Eurycoma longifolia) is a herbal root worldwide available in nutraceuticals, either as a crude powder or capsules blended with other herbal products. Herein, a multiplexed metabolomics approach based on nuclear magnetic resonance (NMR) and solid-phase microextraction combined with gas chromatography-mass spectrometry (SPME-GC-MS) was applied for authentic tongkat ali extract vs some commercial products quality control analysis. NMR metabolite fingerprinting identified 15 major metabolites mostly ascribed to sugars, organic and fatty acids in addition to quassinoids and cinnamates. Following that, multivariate analysis as the non-supervised principal component analysis (PCA) and supervised orthogonal partial least squares-discriminant analysis (OPLS-DA) were applied revealing that differences were related to fatty acids and 13,21-dihydroeurycomanone being more enriched in authentic root. SPME-GC-MS aroma profiling led to the identification of 59 volatiles belonging mainly to alcohols, aldehydes/furans and sesquiterpene hydrocarbons. Results revealed that aroma of commercial products showed relatively different profiles being rich in vanillin, maltol, and methyl octanoate. Whereas E-cinnamaldehyde, endo-borneol, terpinen-4-ol, and benzaldehyde were more associated to the authentic product. The present study shed the light for the potential of metabolomics in authentication and standardization of tongkat ali and identification of its true flavor composition.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  8. Tran TV, Jalil AA, Nguyen TM, Nguyen TTT, Nabgan W, Nguyen DTC
    Environ Toxicol Pharmacol, 2023 Sep;102:104248.
    PMID: 37598982 DOI: 10.1016/j.etap.2023.104248
    Nowadays, microplastic pollution is one of the globally urgent concerns as a result of discharging plastic products into the atmosphere, aquatic and soil environments. Microplastics have average size of less than 5 mm, are non-biodegradable, accumulative, and highly persistent substances. Thousands of tons of microplastics are still accumulated in various environments, posing an enormous threat to human health and living creatures. Here, we review the occurrence and analytical methods, and impact of microplastics in the environments including soil, aquatic media, and atmosphere. Analytical methods including visual observation, Fourier-transform infrared spectroscopy, Raman spectroscopy, scanning electron microscopy, and pyrolysis-gas chromatography-mass spectrometry were evaluated. We elucidated the environmental and human health impacts of microplastics with emphasis on life malfunction, immune disruption, neurotoxicity, diseases and other tangible health risks. This review also found some shortages of analytical equivalence and/or standardization, inconsistence in sampling collection and limited knowledge of microplastic toxicity. It is hopeful that the present work not only affords a more insight into the potential dangers of microplastics on human health but also urges future researches to establish new standardizations in analytical methods.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  9. Salihu AS, Salleh WMNHW, Setzer WN
    Z Naturforsch C J Biosci, 2023 Jul 26;78(7-8):293-298.
    PMID: 36960928 DOI: 10.1515/znc-2023-0003
    Knema is one of the genera in the Myristicaceae family. The genus includes 60 species in Southeast Asia and is traditionally used for treating skin disorders. Here, for the first time, the essential oil, anti-tyrosinase, and molecular docking studies of Knema intermedia were evaluated. The essential oil was obtained by hydrodistillation and fully characterized by gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Anti-tyrosinase activity was evaluated against mushroom tyrosinase, whereas molecular docking studies were performed using Autodock vina embedded in PyRx to evaluate the binding interactions of major components. A total of 37 components (97.3%) were successfully identified in the essential oil, which was characterized by high amounts of t-muurolol (20.1%), α-copaene (14.4%), δ-cadinene (13.9%), germacrene B (9.5%), and δ-selinene (7.0%). The essential oil displayed moderate inhibitory activity towards tyrosinase with an IC50 value of 70.2 μg/mL. The best docking energy was observed with δ-selinene (-7.8 kcal/mol), and it also forms interactions with His85, His263, and His244 which are important amino acid residues of the tyrosinase receptor. Hence, this study provides valuable scientific data on K. intermedia as potential candidate for the development of natural antiaging formulations.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  10. Tay BY, Yung SC, Teoh TY
    Int J Cosmet Sci, 2016 Dec;38(6):627-633.
    PMID: 27169828 DOI: 10.1111/ics.12342
    OBJECTIVE: Isopropyl p-toluenesulfonate (IPTS) is a potentially genotoxic by-product formed during the esterification of palm oil-based palmitic and palm kernel oil-based myristic acid with isopropanol to produce isopropyl palmitate or isopropyl myristate. There are no methods described for the analysis of IPTS in cosmetic products. In this work, we have established a simple, precise and accurate method to determine the presence and level of IPTS in various finished cosmetic products which contain palm-based esters in their formulations.

    METHODS: An Agilent 1200 series high-performance liquid chromatography (HPLC) unit using a diode-array detector (DAD) has been employed and optimized to detect IPTS in cosmetic products. For the separation, a reverse-phase Hypersil Gold C8 column (5 μm, 4.6 mm i.d. 250 mm) 5 mM tetrabutylammonium phosphate buffer 50 : 50, (v/v) solution in acetonitrile as mobile phase, in isocratic mode and a flow rate of 0.8 mL min(-1) were used. A second method using a gas chromatography/mass selective detector GC-MSD was also developed to confirm the IPTS identity in the cosmetic products.

    RESULTS: Recoveries of IPTS from cosmetic matrices such as a lotion, cleansing milk and a cream ranged from 94.0% to 101.1% with <5% relative standard deviation (%RSD) showing good accuracy and repeatability of the method. The six-point calibration curves (determined over the range 0.5-50 μg mL(-1) ) have a correlation coefficient of 0.9999 (based on HPLC peak area) and 0.9998 (based on HPLC peak height). The intra- and interday precisions (measured by the %RSD) of the method were <2% and <5%, respectively, indicating that the developed method is reliable, precise and reproducible. The detection and quantification limit of the method were found to be 0.5 μg mL(-1) and 1.6 μg mL(-1) , respectively. Analyses of 83 commercial cosmetics showed no presence of IPTS.

    CONCLUSIONS: The validation data indicated that this method was suitable for the quantitative analysis of IPTS in commercial cosmetics. This method is applicable for analyses of trace levels of IPTS in cosmetics and has the advantage of using only simple sample preparation steps.

    Matched MeSH terms: Gas Chromatography-Mass Spectrometry/methods*
  11. R R
    Appl Biochem Biotechnol, 2022 Jan;194(1):176-186.
    PMID: 34762268 DOI: 10.1007/s12010-021-03742-2
    Hellenia speciosa (J.Koenig) S.R. Dutta is a plant species belonging to the family Costaceae. It is widely distributed in China, India, Malaysia, Indonesia, tropical, and subtropical Asia. In Ayurveda, the rhizome of this plant has been extensively used to treat fever, rash, asthma, bronchitis, and intestinal worms. The objective of the present study was to investigate the phytochemical constituents of the leaf of Hellenia speciosa using gas chromatography and mass spectroscopy analysis (GC-MS). The GC-MS analysis revealed the presence of 17 phytochemical components in the ethanolic leaf extract of Hellenia speciosa. The prevailing bioactive compounds present in Hellenia speciosa were thymol (RT-10.019; 3.59%), caryophyllene (RT-11.854; 0.62%), caryophyllene oxide (RT-13.919; 1.34%), artumerone (RT-14.795; 1.35%), hexadecanoic acid methyl ester (RT-17.536; 2.77%), 9,12-octadecanoic acid methyl ester (RT-19.163; 1.35%), squalene (RT-24.980; 1.19%), piperine (RT-25.745; 3.11%), beta tocopherol (RT-26.681; 2.88%), vitamin E (RT-27.290; 2.64%), progesterone (RT-29.608; 3.18%), caparratriene (RT-29.861; 9.72%), and testosterone (RT-30.73; 5.81%). The compounds were identified by comparing their retention time and peak area with that of the literature and by interpretation of mass spectra. The results and findings of the present study suggest that the plant leaf can be used as a valuable source in the field of herbal drug discovery. The presence of bioactive compounds justifies the use of plant leaves for treating various diseases with fewer side effects and recommended the plant of pharmaceutical importance. However, further studies are needed to undertake its bioactivity and toxicity profile.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry*
  12. Manickavasagam G, Saaid M, Lim V
    J Food Sci, 2024 Feb;89(2):1058-1072.
    PMID: 38221804 DOI: 10.1111/1750-3841.16903
    Volatile organic compounds in honey are known for their considerable impact on the organoleptic properties of honey, such as aroma, flavor, taste, and texture. The type and composition of volatile organic compounds are influenced by entomological, geographical, and botanical origins; thus, these compounds have the potential to be chemical markers. Sixty-two volatile compounds were identified using gas chromatography-mass spectrometry from 30 Heterotrigona itama (H. itama) honey samples from 3 different geographical origins. Hydrocarbons and benzene derivatives were the dominant classes of volatile organic compounds in the samples. Both clustering and discriminant analyses demonstrated a clear separation between samples from distant origins (Kedah and Perak), and the volcano plot supported it. The reliability and predictability of the partial least squares-discriminant analysis model from the discriminant analysis were validated using cross-validation (R2 : 0.93; Q2 : 0.83; accuracy: 0.97) and the permutation test (p  1.0) and the Kruskal-Wallis test (p 
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry/methods
  13. Pendashteh AR, Fakhru'l-Razi A, Chuah TG, Radiah AB, Madaeni SS, Zurina ZA
    Environ Technol, 2010 Oct;31(11):1229-39.
    PMID: 21046953 DOI: 10.1080/09593331003646612
    Produced water or oilfield wastewater is the largest volume ofa waste stream associated with oil and gas production. The aim of this study was to investigate the biological pretreatment of synthetic and real produced water in a sequencing batch reactor (SBR) to remove hydrocarbon compounds. The SBR was inoculated with isolated tropical halophilic microorganisms capable of degrading crude oil. A total sequence of 24 h (60 min filling phase; 21 h aeration; 60 min settling and 60 min decant phase) was employed and studied. Synthetic produced water was treated with various organic loading rates (OLR) (0.9 kg COD m(-3) d(-1), 1.8 kg COD m(-3) d(-1) and 3.6 kg COD m(-3) d(-1)) and different total dissolved solids (TDS) concentration (35,000 mg L(-1), 100,000 mg L(-1), 150,000 mg L(-1), 200,000 mg L(-1) and 250,000 mg L(-1)). It was found that with an OLR of 0.9 kg COD m(-3) d(-1) and 1.8 kg COD m(-3) d(-1), average oil and grease (O&G) concentrations in the effluent were 7 mg L(-1) and 12 mg L(-1), respectively. At TDS concentration of 35,000 mg L(-1) and at an OLR of 1.8 kg COD m(-3)d(-1), COD and O&G removal efficiencies were more than 90%. However, with increase in salt content to 250,000 mg L(-1), COD and O&G removal efficiencies decreased to 74% and 63%, respectively. The results of biological treatment of real produced water showed that the removal rates of the main pollutants of wastewater, such as COD, TOC and O&G, were above 81%, 83%, and 85%, respectively.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  14. Salleh WMNHW, Shakri NM, Khamis S, Setzer WN, Nadri MH
    Nat Prod Res, 2020 Sep 14.
    PMID: 32927975 DOI: 10.1080/14786419.2020.1819274
    This study aims to assess the chemical compositions of the essential oils from three Horsfieldia species namely H. fulva Warb., H. sucosa Warb. and H. superba Warb., which are found in Malaysia. The essential oils were derived from the samples through hydrodistillation which were then characterised by gas chromatography (GC-FID) and gas chromatography-mass spectrometry (GC-MS). Based on the findings, the H. fulva, H. sucosa and H. superba essential oils represented 98.2%, 98.7% and 98.5% of the total oils, respectively. The major component of H. fulva oil was identified to be germacrene D (20.8%), H. sucosa oil mainly contained α-cadinol (17.5%), whereas H. superba oil was rich in δ-cadinene (18.2%). To the best of our knowledge, this is the first study of the composition of the essential oils from these selected Horsfieldia species.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  15. Kamal, G.M., Anwar, F., Hussain, A.I., Sarri, N., Ashraf, M.Y.
    Citrus peel essential oils have an impressive range of food and medicinal uses. In the present study we investigated the variation in the yield and chemical composition of the essential oils isolated from fresh, ambient-, and oven-dried peels of three Citrus species namely Citrus reticulata (C. reticulata), Citrus sinensis (C. sinensis) and Citrus paradisii (C. paradisii). The hydro-distilled essential oil content from fresh-, ambient-, and oven-dried peels of C. reticulata, C. sinensis and C. paradisii ranged from 0.30-0.50, 0.24-1.07 and 0.20-0.40 g/100 g, respectively. The maximum amount of the oil was determined in oven-dried while the minimum in fresh peel samples. Using GC and GC/MS, a total of 16-27, 17-24 and 18-40 chemical constituents were identified in the peel essential oils of C. reticulate, C. sinensis and C. paradisii, respectively. The content of limonene, the most prevalent chemical constituent, detected in these essential oils, ranged from 64.1-71.1% (C. reticulata), 66.8-80.9% (C. sinensis) and 50.8-65.5% (C. paradisii). The yield and content of most of the chemical components including limonene (the principal chemical compound detected) of the tested essential oils varied significantly (p < 0.05) with respect to drying treatments and species employed.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  16. Raja Zubaidah Raja Sabaradin, Norashikin Saim, Rozita Osman, Hafizan Juahir
    Pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) has been recognised as an effective technique to analyse car paint. This study was conducted to assess the combination of Py-GC-MS and chemometric techniques to classify car paint primer, the inner layer of car paint system. Fifty car paint primer samples from various manufacturers were analysed using Py-GC-MS, and data set of identified pyrolysis products was subjected to principal component analysis (PCA) and discriminant analysis (DA). The PCA rendered 16 principal components with 86.33% of the total variance. The DA was useful to classify the car paint primer samples according to their types (1k and 2k primer) with 100% correct classification in the test set for all three modes (standard, stepwise forward and stepwise backward). Three compounds, indolizine, 1,3-benzenedicarbonitrile and p-terphenyl, were the most significant compounds in discriminating the car paint primer samples.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  17. Masni Mohd Ali, Norfariza Humrawali, Mohd Talib Latif, Mohamad Pauzi Zakaria
    This study explores the role of sterols as lipid biomarkers to indicate their input which originates from various sources in the marine environment. Sterols and their ratios were investigated in sediments taken from sixteen sampling stations at Pulau Tinggi, Johor in order to assess the sources of organic matter. The compounds extracted from the sediments were quantified using a gas chromatography-mass spectrometry (GC-MS). The distributions of sterols indicated that organic matter at all sampling stations originated from a mixture of marine source and terrestrial origins at different proportions. A total of eleven sterols were quantified, with the major compounds being phytosterols (44% of total sterols), cholesterol (11%), brassicasterol (11%) and fecal sterols (12%).
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  18. Lee HW, Farooq A, Jang SH, Kwon EE, Jae J, Lam SS, et al.
    Environ Res, 2020 May;184:109311.
    PMID: 32145550 DOI: 10.1016/j.envres.2020.109311
    Catalytic co-pyrolysis (CCP) of spent coffee ground (SCG) and cellulose over HZSM-5 and HY was characterized thermogravimetrically, and a catalytic pyrolysis of two samples was conducted using a tandem micro reactor that directly connected with gas chromatography-mass spectrometry. To access the more fundamental investigations on CCP, the effects of the zeolite pore structure, reaction temperature, in-situ/ex-situ reaction mode, catalyst to feedstock ratio, and the SCG and cellulose mixing ratio were experimentally evaluated. The temperature showing the highest thermal degradation rate of cellulose with SCG slightly delayed due to the interactions during the thermolysis of two samples. HZSM-5 in reference to HY produced more aromatic hydrocarbons from CCP. With respect to the reaction temperature, the formation of aromatic hydrocarbons increased with the pyrolytic temperature. Moreover, the in-situ/ex-situ reaction mode, catalyst/feedstock, and cellulose/SCG ratio were optimized to improve the aromatic hydrocarbon yield.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  19. Ba-Abbad MM, Takriff MS, Kadhum AA, Mohamad AB, Benamor A, Mohammad AW
    Environ Sci Pollut Res Int, 2017 Jan;24(3):2804-2819.
    PMID: 27837474 DOI: 10.1007/s11356-016-8033-y
    In this study, the photocatalytic degradation of toxic pollutant (2-chlorophenol) in the presence of ZnO nanoparticles (ZnO NPs) was investigated under solar radiation. The three main factors, namely pH of solution, solar intensity and calcination temperature, were selected in order to examine their effects on the efficiency of the degradation process. The response surface methodology (RSM) technique based on D-optimal design was applied to optimise the process. ANOVA analysis showed that solar intensity and calcination temperature were the two significant factors for degradation efficiency. The optimum conditions in the model were solar intensity at 19.8 W/m(2), calcination temperature at 404 °C and pH of 6.0. The maximum degradation efficiency was predicted to be 90.5% which was in good agreement with the actual experimental value of 93.5%. The fit of the D-optimal design correlated very well with the experimental results with higher values of R (2) and R (2)adj correlation coefficients of 0.9847 and 0.9676, respectively. The intermediate mechanism behaviour of the 2-chlorophenol degradation process was determined by gas chromatography-mass spectrometry (GC-MS). The results confirmed that 2-chlorophenol was converted to acetic acid, a non-toxic compound.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry
  20. Baharum SN, Bunawan H, Ghani MA, Mustapha WA, Noor NM
    Molecules, 2010 Oct 12;15(10):7006-15.
    PMID: 20944520 DOI: 10.3390/molecules15107006
    The essential oil in leaves of Polygonum minus Huds., a local aromatic plant, were identified by a pipeline of gas chromatography (GC) techniques coupled with mass-spectrometry (MS), flame ionization detector (FID) and two dimensional gas chromatography time of flight mass spectrometry (GC x GC-TOF MS). A total of 48 compounds with a good match and high probability values were identified using this technique. Meanwhile, 42 compounds were successfully identified in this study using GC-MS, a significantly larger number than in previous studies. GC-FID was used in determining the retention indices of chemical components in P. minus essential oil. The result also showed the efficiency and reliability were greatly improved when chemometric methods and retention indices were used in identification and quantification of chemical components in plant essential oil.
    Matched MeSH terms: Gas Chromatography-Mass Spectrometry/instrumentation; Gas Chromatography-Mass Spectrometry/methods*
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