Displaying publications 1 - 20 of 25 in total

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  1. Siang GH, Makahleh A, Saad B, Lim BP
    J Chromatogr A, 2010 Dec 24;1217(52):8073-8.
    PMID: 21081239 DOI: 10.1016/j.chroma.2010.10.052
    The development of a two phase hollow fiber liquid-phase microextraction technique, followed by gas-chromatography-flame ionization detection (GC-FID) for the profiling of the fatty acids (FAs) (lauric, myristic, palmitic, stearic, palmitoleic, oleic, linoleic, linolenic and arachidic) in vegetable oils is described. Heptadecanoic acid methyl ester was used as the internal standard. The FAs were transesterified to their corresponding methyl esters prior to the extraction. Extraction parameters such as type of extracting solvent, temperature, extraction time, stirring speed and salt addition were studied and optimized. Recommended conditions were extraction solvent, n-tridecane; extraction time, 35 min; extraction temperature, ambient; without addition of salt. Enrichment factors varying from 37 to 115 were achieved. Calibration curves for the nine FAs were well correlated (r(2)>0.994) within the range of 10-5000 μg L(-1). The limit of detection (signal:noise, 3) was 4.73-13.21 ng L(-1). The method was successfully applied to the profiling of the FAs in palm oils (crude, olein, kernel, and carotino cooking oil) and other vegetable oils (soybean, olive, coconut, rice bran and pumpkin). The encouraging enrichments achieved offer an interesting option for the profiling of the minor and major FAs in palm and other vegetable oils.
    Matched MeSH terms: Flame Ionization/instrumentation; Flame Ionization/methods*
  2. Danish M, Nizami M
    Data Brief, 2019 Apr;23:103845.
    PMID: 31372470 DOI: 10.1016/j.dib.2019.103845
    The data presented in this article were generated through the gas chromatography (GC) with a flame ionization detector (FID). The flaxseed oil was converted into fatty acid methyl ester (FAME) then used in the GC with FID and observe the retention time of different fatty acid present in the flaxseed oil. The observed retention time was compared with the standard fatty acid to confirm the specific fatty acid presence in the flaxseed oil. The part of the data is used in the article "Optimization of the process variable for biodiesel production by transesterification of flaxseed oil and produced biodiesel characterizations" Renewable Energy journal (Ahmad et al., 2019).
    Matched MeSH terms: Flame Ionization
  3. Myint S, Daud WR, Mohamad AB, Kadhum AA
    J Chromatogr B Biomed Appl, 1996 Apr 26;679(1-2):193-5.
    PMID: 8998560
    An ethanolic extract of cloves was analyzed by gas chromatography directly to identify eugenol and other major phenolic compounds without previous separation of other components. Separation was performed on a fused-silica capillary column of 30 m x 0.53 mm I.D., 0.53 microns film thickness. The detector was a flame ionization detector. Helium gas at a flow-rate of 3 ml/min was used as a carrier gas. The analysis were performed with linear temperature programming. Nine components were detected and special attention was given to the major phenolic compound, eugenol.
    Matched MeSH terms: Flame Ionization/methods
  4. Zahidah Ayob, Shajarahtunnur Jamil, Siti Pauliena Mohd Bohari, Farediah Ahmad, Azman Abd Samad
    Sains Malaysiana, 2017;46:457-461.
    Justicia gendarussa methanolic leaves extract from four different locations in Southern region of Malaysia and distribution
    of two flavonoids, naringenin and kaempferol in plant organs (young and mature leaves) were determined using gas
    chromatography-flame ionization detector (GC-FID) analysis. Naringenin and kaempferol contents were detected
    and quantified in leaves extract. The results indicated that mature leaves contained more naringenin and kaempferol
    compared to young leaves. The highest concentration of naringenin and kaempferol were recorded in mature leaves from
    Skudai and Muar regions which were 507.692 and 1226.964 mgkg-1, respectively. Data analysis showed that naringenin
    content was directly proportional to the amount of kaempferol in the leaf extracts. In conclusion, this study suggested
    geographical variation among plant samples and physiological stage of organ parts could contribute to variation in
    flavonoids concentration in a plant species.
    Matched MeSH terms: Flame Ionization
  5. MyJurnal
    The fatty acid composition and trans fatty acid (TFA) contents of biscuits products were determined by gas chromatography, using a highly polar 100m capillary column (HP-88) and flame ionization detection. Total TFA ranged from 0.00 – 0.52 g/100 g total fatty acids and 0.12 – 0.68 g/100 g total fatty acids for local packed and unpacked biscuits, respectively. In imported biscuits, total TFA was higher ranging from 0.03 – 3.09 g/100 g of total fatty acids. Trans 16:1 was the most abundant, with values ranging from 0.01% to 38% followed by trans 18:1 Δ11 (0.01% - 13.11%), trans 18:1 Δ9 (0.01% - 4.68%), trans 18:2 (0.23% - 2.77%) and small quantities of trans 18:1 Δ6. CLA, the natural TFA constituted from 0.1% to
    Matched MeSH terms: Flame Ionization
  6. Khaldun M. Al Azzam, Bahruddin, S., Noor Hasani Hashim, Afidah Abdul Rahim, Khairuddin Mohd Talib
    MyJurnal
    A simple analytical method for the determination of propionic acid and propionates in bakery products using a simple sample preparation procedure is described. The method involves the conversion of propionates to the non-ionized molecular form by adding glacial acetic acid, which is at the same time efficiently extracted into dichloromethane. After vortexing for 1 min, the extract was directly injected into a capillary gas chromatographic column with flame ionization detector. The method was applied for the determination of propionates in 112 commercial bakery samples. The levels of propionic acid plus propionates in bread, cake/ rolls, burger/hot dog buns and pita breads ranged from 197-1273, 98-1846, 546-1932 and 479-1680 µg mL -1 , respectively. No propionate was detected in any of the 36 biscuit samples analyzed.
    Matched MeSH terms: Flame Ionization
  7. 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: Flame Ionization/instrumentation; Flame Ionization/methods
  8. Chang KH, Yew CH, Abdullah AF
    J Forensic Sci, 2014 Jul;59(4):1100-8.
    PMID: 24611488 DOI: 10.1111/1556-4029.12440
    Smokeless powders are low explosives and are potentially found in cases involving firearms and improvised explosive devices. Apart from inorganic compound analysis, forensic determination of organic components of these materials appears as a promising alternative, especially the chromatographic techniques. This work describes the optimization of a solid-phase microextraction technique using an 85 μm polyacrylate fiber followed by gas chromatography-flame ionization detection for smokeless powder. A multivariate experimental design was performed to optimize extraction-influencing parameters. A 2(4) factorial first-order design revealed that sample temperature and extraction time were the major influencing parameters. Doehlert matrix design has subsequently selected 66°C and 21 min as the compromised conditions for the two predetermined parameters. This extraction technique has successfully detected the headspace compounds of smokeless powders from different ammunition types and allowed for their differentiation. The novel technique allows more rapid sample preparation for chromatographic detection of smokeless powders.
    Matched MeSH terms: Flame Ionization
  9. Siti Nurshahbani, S., Azrina, A.
    MyJurnal
    High intake of trans fatty acids (TFA) may cause adverse changes in blood lipids as shown in many epidemiological studies. The major sources of TFA in human diet come from bakery products such as cookies, cakes, muffins, breads and pastries. In this study, total fat of baked products was determined using Soxhlet method while TFA content was determined on gas chromatograph using a highly polar capillary column and flame ionization detector. Exposure to TFA from the baked product was estimated based on Food Consumption Statistics of Malaysia 2003. High level of TFA was observed in muffins (3.21-7.34 g per 100 g food) followed by pastries (2.90-6.03 g per 100 g food) and cakes (2.26-8.36 g per 100 g food) regardless of products having brand name or not. Among the TFA isomers, trans 18:1 6t was the most abundant followed by trans 18:1 9t, trans 16:1 9t, trans 18:2 and small quantities of trans 18:1 11t. Exposure to TFA based on the Malaysian Food Consumption Statistics 2003 of the baked products was ranging from 0.14-0.18 g/day. Even with the low estimated exposure, actual intake of baked products must be monitored closely as other high fat food as these products is one of main contributor to TFA in the diet following their high frequency of daily intake.
    Matched MeSH terms: Flame Ionization
  10. Nurlaila Ismail, Mohd Hezri Fazalul Rahiman, Mohd Nasir Taib, Mastura Ibrahim, Seema Zareen, Saiful Nizam Tajuddin
    MyJurnal
    This paper presents the application of Solid Phase Micro Extraction (SPME) coupled with Gas Chromatography - Mass Spectrometry (GC-MS) and Gas Chromatography - Flame Ionization Detector (GC-FID) in characterizing the agarwood incense. The work involved three types of SPME fibres at 30 minute sampling time. The fibres are 50/30 μm divinylbenzene-carboxen-polydimethysiloxane (DVB-CAR-PDMS), 65 μm polydi methylsiloxane-divinylbenzene (PDMS-DVB) and 85 μm carboxen-polydimethyl siloxane (CAR-PDMS). The results showed that among the many compounds extracted by GC-MS coupled with SPME, six compounds were substantially found in high quality agarwood incense due to their high percentage area (%). They are β-maaliene, α-elemol, β-selinene, 10-epi-γ-eudesmol, agarospirol and caryophellene oxide. The finding offers a new approach for establishing the volatile profile of agarwood incense components as well as for agarwood grading and discrimination.
    Matched MeSH terms: Flame Ionization
  11. Neo, Y.P., Tan, C.H., Ariffin, A.
    MyJurnal
    The fatty acid composition and trans fatty acids (TFA) contents of samples of five Malaysian cream crackers biscuit brands were determined by gas-liquid chromatography, using a 60 m Supelco SP2340 fused silica capillary column and flame ionization detection. The identities of the fatty acids were established by comparing their retention times with authentic standards from Supelco. The results were expressed as relative percentages. The total saturated fatty acids (SFA) in the samples ranged from 48.90% to 54.87% of total fatty acids. As for the polyunsaturated fatty acids (PUFA), the total PUFA in the samples ranged from 9.97% to 11.73% of total fatty acids. Total trans fatty acids (TFA) ranged from 0.17% to 0.77% of total fatty acids. The monotrans 18:2 tc or 18:2 ct isomer content ranged from 0.07% to 0.10% of total fatty acids and the ditrans 18:2 isomer (9t, 12t) was not detected. The results indicate that all the fat sources of the 5 sample crackers biscuit brands were palm oil based.
    Matched MeSH terms: Flame Ionization
  12. Rahman N, Xin TB, Kamilah H, Ariffin F
    J Food Sci Technol, 2018 Jan;55(1):183-189.
    PMID: 29358809 DOI: 10.1007/s13197-017-2883-2
    The effects of osmotic dehydration (OD) treatment on volatile compound (myristicin) content and the antioxidant capacity of nutmeg (Myristica fragrans) were studied. Fresh nutmeg pericarps were treated with varying sugar concentrations (60, 70, 80%) with different soaking periods at ambient temperature. The OD-treated nutmeg extracts were analyzed for myristicin content via Gas Chromatography Flame Ionization Detector. The phenolic content and antioxidant capacity were analyzed using Follin-Ciocalteu and a free radical scavenging activity assay. The myristicin content was highest (1.69 mg/100 mg) at 80% sugar concentration after 3 h of soaking. Total phenolic content and free radical scavenging activity were highest at 3 h of 80% sugar solution treatment with values of 76.90% and 1.75 mg GAE/g, respectively. OD treatment at varying sugar concentration levels and durations affects the production of myristicin and antioxidant composition. Treatment of nutmeg with OD at 80% sugar concentration for 3 h is preferable, resulting in an acceptable level of myristicin and high antioxidants.
    Matched MeSH terms: Flame Ionization
  13. Chan KB, Pakiam C, Rahim RA
    Bull Narc, 2005;57(1-2):249-56.
    PMID: 21338025
    Recently, the abuse of ketum, an indigenous psychoactive plant, has received a lot of attention in Malaysia. To help national law enforcement agencies control its abuse, the laboratory of the Forensic Division has developed a procedure for its positive identification. Botanical identification may not be practical or conclusive, owing to the wide range of ketum materials available on the market, including dry macerated leaves, powdered leaves and drinks. In order to confirm that a substance is, in fact, ketum or that a preparation is derived from ketum, gas chromatography-mass spectrometry is used to definitively identify the presence of the psychoactive principle mnitragynine.
    Matched MeSH terms: Flame Ionization/methods
  14. Lau HL, Puah CW, Choo YM, Ma AN, Chuah CH
    Lipids, 2005 May;40(5):523-8.
    PMID: 16094863
    This paper discusses a rapid GC-FID technique for the simultaneous quantitative analysis of FFA, MAG, DAG, TAG, sterols, and squalene in vegetable oils, with special reference to palm oil. The FFA content determined had a lower SE compared with a conventional titrimetric method. Squalene and individual sterols, consisting of beta-sitosterol, stigmasterol, campesterol, and cholesterol, were accurately quantified without any losses. This was achieved through elimination of tedious conventional sample pretreatments, such as saponification and preparative TLC. With this technique, the separation of individual MAG, consisting of 16:0, 18:0, and 18:1 FA, and the DAG species, consisting of the 1,2(2,3)- and 1,3-positions, was sufficient to enable their quantification. This technique enabled the TAG to be determined according to their carbon numbers in the range of C44 to C56. Comparisons were made with conventional methods, and the results were in good agreement with those reported in the literature.
    Matched MeSH terms: Flame Ionization/methods
  15. Hassan H, Othman MF, Zakaria ZA, Saad FFA, Abdul Razak HR
    Curr Radiopharm, 2021;14(2):131-144.
    PMID: 33115398 DOI: 10.2174/1874471013999201027215704
    BACKGROUND: Organic solvents play an indispensable role in most of the radiopharmaceutical production stages. It is almost impossible to remove them entirely in the final formulation of the product.

    OBJECTIVE: In this presented work, an analytical method by gas chromatography coupled with flame ionization detection (GC-FID) has been developed to determine organic solvents in radiopharmaceutical samples. The effect of injection holding time, temperature variation in the injection port, and the column temperature on the analysis time and resolution (R ≥ 1.5) of ethanol and acetonitrile was studied extensively.

    METHODS: The experimental conditions were optimized with the aid of further statistical analysis; thence, the proposed method was validated following the International Council for Harmonisation (ICH) Q2 (R1) guideline.

    RESULTS: The proposed analytical method surpassed the acceptance criteria including the linearity > 0.990 (correlation coefficient of R2), precision < 2%, LOD, and LOQ, accuracy > 90% for all solvents. The separation between ethanol and acetonitrile was acceptable with a resolution R > 1.5. Further statistical analysis of Oneway ANOVA revealed that the increment in injection holding time and variation of temperature at the injection port did not significantly affect the analysis time. Nevertheless, the variation in injection port temperature substantially influenced the resolution of ethanol and acetonitrile peaks (p < 0.05).

    CONCLUSION: The proposed analytical method has been successfully implemented to determine the organic solvent in the [18F]fluoro-ethyl-tyrosine ([18F]FET), [18F]fluoromisonidazole ([18F]FMISO), and [18F]fluorothymidine ([18F]FLT).

    Matched MeSH terms: Flame Ionization/methods*
  16. Chang KH, Yew CH, Abdullah AF
    J Forensic Sci, 2015 Jul;60(4):869-77.
    PMID: 25771708 DOI: 10.1111/1556-4029.12745
    Gunshot residues, produced after shooting activity, have acquired their importance in analysis due to the notoriety of firearms-related crimes. In this study, solid-phase microextraction was performed to extract the headspace composition of spent cartridges using 85-μm polyacrylate fiber at 66°C for 21 min. Organic compounds, that is, naphthalene, 2,6-dinitrotoluene, 2,4-dinitrotoluene, diphenylamine, and dibutyl phthalate were detected and analyzed by gas chromatography-flame ionization detection technique. Evaluation of chromatograms for diphenylamine, dibutyl phthalate, and naphthalene indicates the period after a gunshot was discharged, whether it was 1 days, 2-4 days, <5 days, 10 days, 20 days, or more than 30 days ago. This study revealed the potential effects of environmental factors such as occasional wind blow and direct sunlight on the estimation of time after spent cartridges were discharged. In conclusion, we proposed reliable alternative in analyzing the headspace composition of spent cartridges in a simulated crime scene.
    Matched MeSH terms: Flame Ionization
  17. Ahmad Hazmi AS, Abd Maurad Z, Mohd Noor MA, Nek Mat Din NSM, Idris Z
    J Sep Sci, 2021 Apr;44(7):1471-1481.
    PMID: 33522105 DOI: 10.1002/jssc.202000929
    Ethylene glycol is a super commodity chemical and it has vital roles in various applications. Its co-production with other chemicals, such as ethylene carbonate and glycerol carbonate, has promised cheaper production cost. Its quantification presents a challenge as its contaminants, such as ethylene carbonate, produce a signal-reducing effect in flame ionized detector. The aim of this study is to evaluate external standard to quantify the composition of glycol mixture. Measurement system analysis was employed on the external standard method. Reliability of the external standard is statistically significant with low p-values, excellent capability indices, and high F-values. The external standard is found to have remarkable precision and trueness as both capability indices are mirroring each other. Furthermore, the capability analysis has a strong correlation with quality measurement. Based on capability indices, the limit of detection is recommended at S/N = 25 and the limit of quantification is recommended at S/N = 100 for a reliable measurement. A high degree of reliability is achieved coherently as almost all uncertainties of coefficients of variations are less than 5%. The established method was validated and successfully applied to glycol mixture at azeotropic distillation pilot plant.
    Matched MeSH terms: Flame Ionization
  18. Rezvani-Eivari M, Amiri A, Baghayeri M, Ghaemi F
    J Chromatogr A, 2016 Aug 16.
    PMID: 27578405 DOI: 10.1016/j.chroma.2016.08.034
    The application of magnetized graphene (G) layers synthesized on the carbon nanofibers (CNFs) (m-G/CNF) was investigated as novel adsorbent for the magnetic solid-phase extraction (MSPE) of polycyclic aromatic hydrocarbons (PAHs) in water samples followed by gas chromatography-flame ionization detector (GC-FID). Six important parameters, affecting the extraction efficiency of PAHs, including: amount of adsorbent, adsorption and desorption times, type and volume of the eluent solvent and salt content of the sample were evaluated. The optimum extraction conditions were obtained as: 5min for extraction time, 20mg for sorbent amount, dichloromethane as desorption solvent, 1mL for desorption solvent volume, 5min for desorption time and 15% (w/v) for NaCl concentration. Good performance data were obtained at the optimized conditions. The calibration curves were linear over the concentration ranges from 0.012 to 100ngmL(-1) with correlation coefficients (r) between 0.9950 and 0.9967 for all the analytes. The limits of detection (LODs, S/N=3) of the proposed method for the studied PAHs were 0.004-0.03ngmL(-1). The relative standard deviations (RSDs) for five replicates at two concentration levels (0.1 and 50ngmL(-1)) of PAHs were ranged from 3.4 to 5.7%. Appropriate relative recovery values, in the range of 95.5-99.9%, were also obtained for the real water sample analysis.
    Matched MeSH terms: Flame Ionization
  19. Azir M, Abbasiliasi S, Tengku Ibrahim TA, Manaf YNA, Sazili AQ, Mustafa S
    Foods, 2017 Nov 09;6(11).
    PMID: 29120362 DOI: 10.3390/foods6110098
    The present study investigates the detection of lard in cocoa butter through changes in fatty acids composition, triacylglycerols profile, and thermal characteristics. Cocoa butter was mixed with 1% to 30% (v/v) of lard and analyzed using a gas chromatography flame ionization detector, high performance liquid chromatography, and differential scanning calorimetry. The results revealed that the mixing of lard in cocoa butter showed an increased amount of oleic acid in the cocoa butter while there was a decrease in the amount of palmitic acid and stearic acids. The amount of POS, SOS, and POP also decreased with the addition of lard. A heating thermogram from the DSC analysis showed that as the concentration of lard increased from 3% to 30%, two minor peaks at -26 °C and 34.5 °C started to appear and a minor peak at 34.5 °C gradually overlapped with the neighbouring major peak. A cooling thermogram of the above adulterated cocoa butter showed a minor peak shift to a lower temperature of -36 °C to -41.5 °C. Values from this study could be used as a basis for the identification of lard from other fats in the food authentication process.
    Matched MeSH terms: Flame Ionization
  20. Ayob Z, Mohd Bohari SP, Abd Samad A, Jamil S
    PMID: 25574182 DOI: 10.1155/2014/732980
    Justicia gendarussa methanolic leaf extracts from five different locations in the Southern region of Peninsular Malaysia and two flavonoids, kaempferol and naringenin, were tested for cytotoxic activity. Kaempferol and naringenin were two flavonoids detected in leaf extracts using gas chromatography-flame ionization detection (GC-FID). The results indicated that highest concentrations of kaempferol and naringenin were detected in leaves extracted from Mersing with 1591.80 mg/kg and 444.35 mg/kg, respectively. Positive correlations were observed between kaempferol and naringenin concentrations in all leaf extracts analysed with the Pearson method. The effects of kaempferol and naringenin from leaf extracts were examined on breast cancer cell lines (MDA-MB-231 and MDA-MB-468) using MTT assay. Leaf extract from Mersing showed high cytotoxicity against MDA-MB-468 and MDA-MB-231 with IC50 values of 23 μg/mL and 40 μg/mL, respectively, compared to other leaf extracts. Kaempferol possessed high cytotoxicity against MDA-MB-468 and MDA-MB-231 with IC50 values of 23 μg/mL and 34 μg/mL, respectively. These findings suggest that the presence of kaempferol in Mersing leaf extract contributed to high cytotoxicity of both MDA-MB-231 and MDA-MB-468 cancer cell lines.
    Matched MeSH terms: Flame Ionization
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