Solid-phase microextraction combined with comprehensive two-dimensional gas chromatography for fatty acid profiling of cell wall phospholipids

2012 ◽  
Vol 35 (18) ◽  
pp. 2438-2444 ◽  
Author(s):  
Stanislau Bogusz ◽  
Leandro Wang Hantao ◽  
Soraia Cristina Gonzaga Neves Braga ◽  
Valtenice de Cássia Rodrigues de Matos França ◽  
Marcelo Fernandes da Costa ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Cell Wall ◽  
Fatty Acid ◽  
Solid Phase Microextraction ◽  
Solid Phase ◽  
Two Dimensional ◽  
Fatty Acid Profiling

Evaluation of Orchid-Like Aroma Between Different Grades of Taiping Houkui Tea by Solid-Phase Microextraction and Comprehensive Two-Dimensional Gas Chromatography Coupled with Time-of-Fight Mass Spectrometry

2020 ◽  
Vol 103 (2) ◽  
pp. 433-438
Author(s):  
Chen Qi ◽  
Guo Tianyang ◽  
Wu Qiong ◽  
Yao Jian ◽  
Liao Renyi ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Solid Phase Microextraction ◽  
Solid Phase ◽  
Low Grade ◽  
Two Dimensional ◽  
Material Basis ◽  
Quality Grade ◽  
Gaseous Sample ◽  
Grade One

Abstract Background: Taiping houkui tea won the title of “the King of Green Tea” at the International Tea Exposition in 2004, which had an orchid fragrance but the material basis of the orchid fragrance had not been revealed yet. Objective: To investigate the material basis of the orchid fragrance and identify the quality grade of Taiping houkui tea. Methods: A method was developed for evaluating orchid-like aroma between different grades Taiping houkui tea by solid-phase micro extraction (SPME) and comprehensive two-dimensional gas chromatography coupled with time-of-fight mass spectrometry (GC×GC-TOFMS). The crushed tea sample in a 25 mL headspace bottle was incubated at 90°C for 10 min. Then the gaseous sample was extracted by SPME divinylbenzene/polydimethylsiloxane fiber for 50 min and thermally desorpted at 250°C for 2 min. Results: In total, 735 volatile compounds were determined by SPME- GC×GC-TOFMS and 15 compounds were related to orchid-like aroma. Conclusions: The high-quality Taiping houkui tea has the orchid fragrance and the low-grade one does not; thus orchid-like aroma can be used as a reference of grades of Taiping houkui tea. Highlights: Thirty different grades of Taiping houkui tea samples were compared and analyzed experimentally, and the results showed that the special aroma substances, which played a key role in grade discrimination of Taiping houkui tea, were found by the statistical method.

scholarly journals Headspace Solid-Phase Microextraction Coupled to Comprehensive Two-Dimensional Gas Chromatography Time-of-Flight Mass Spectrometry for the Determination of Short-Chain Chlorinated Paraffins in Water Samples

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Nan Zhan ◽  
Feng Guo ◽  
Shuai Zhu ◽  
Zhu Rao
Keyword(s):  
Mass Spectrometry ◽  
Gas Chromatography ◽  
Water Samples ◽  
Solid Phase Microextraction ◽  
Solid Phase ◽  
Short Chain ◽  
Two Dimensional ◽  
Flight Mass Spectrometry ◽  
Chlorinated Paraffins

Short-chain chlorinated paraffins (SCCPs) are a new type of persistent organic pollutants. In this work, a simple and effective method involving headspace solid-phase microextraction (HS-SPME) and comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC × GC-TOF-MS) was developed and optimized for the determination of trace SCCPs in water samples. The key parameters related to extraction and separation efficiency were systematically optimized. The SCCP congener groups were best resolved using an Rxi-5Sil MS (30 m × 0.25 mm × 0.25 µm) column followed by an Rxi-17Sil MS (1.0 m × 0.15 mm × 0.15 µm) column; the optimum extraction conditions were achieved with a 100 µm polydimethylsiloxane SPME fiber, when a 10 mL water sample added with 3.6 g sodium chloride was incubated for 15 min at 90°C and then extracted during 60 min at 90°C and desorption at 260°C for 2 min. The proposed method showed good linearity in the concentration range of 0.2–20.0 µg/L with the determination coefficient greater than 0.995. The detection and quantification limits ranged from 0.06 to 0.13 µg/L and 0.18 to 0.40 µg/L, respectively, which are sufficient to meet the regulatory detection limits as set by most environmental regulations. The accuracy and precision of the method was also good, where the recoveries ranged from 82.5 to 95.4%, and intra- and interday precision was within 7.2% and 14.5%, respectively. The optimized method has been applied to the determination of SCCPs in ten freshwater samples of three different types.

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