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Hollow fiber liquid-phase microextraction coupled with gas chromatography-flame ionization detection for the profiling of fatty acids in vegetable oils

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/methods*
Gas chromatographic determination of eugenol in ethanol extract of cloves

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
Fulltext Psychoactive plant abuse: the identification of mitragynine in ketum and in ketum preparations

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
Simultaneous quantification of free fatty acids, free sterols, squalene, and acylglycerol molecular species in palm oil by high-temperature gas chromatography--flame ionization detection

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
Analytical GC-FID Method for the Determination of Organic Solvents in Radiopharmaceuticals

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*
Fulltext Analysis of the chemical composition of the essential oil of Polygonum minus Huds. using two-dimensional gas chromatography-time-of-flight mass spectrometry (GC-TOF MS)

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/methods