• Bulletin of the Korean Chemical Society
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• v.30 no.11
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• pp.2675-2679
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• 2009

This paper reports the example of headspace mulberry paper bag micro solid phase extraction (HS-MPB-$\mu$-SPE) as a new sampling method for the determination of volatile flavor composition of coriander seeds. Adsorption efficiencies between two configurations of mulberry paper bag were compared, and several parameters affecting the HS-MPB-$\mu$-SPE were investigated and optimized. The optimized technique uses an adsorbent (Tenax TA, 0.1 mg) contained in a mulberry paper bag of front configuration where fine surface was outside, and minimal amount of organic solvent (0.6 mL). Linalool and $\gamma$-terpinene were found as abundant flavor compounds from coriander seeds. The limit of detection (LOD) and the limit of quantitation (LOQ) for linalool of major flavor in coriander seeds were 10.3 ng/mL and 34.4 ng/mL, respectively. The proposed method showed good reproducibility and good recovery. The HS-MPB-$\mu$-SPE is very simple to use, inexpensive, requires small sample amounts and solvent consumption. Because the solvent for extraction is reduced to only a very small volume, there is minimal waste or exposure to toxic organic solvent and no further concentration step.

• Bulletin of the Korean Chemical Society
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• v.31 no.12
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• pp.3755-3759
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• 2010

A on-line SPE (solid phase extraction)-HPLC preconcentration method was developed for the determination of phenolic compounds at trace levels in environmental water sample. XAD-4 and Dowex 1-X8 were used as sorbent in the on-line SPE-HPLC method for the selective enrichment of nine phenolic compounds, which are included in the priority pollutants list of the US EPA. Also alumina prefiltering considerably reduced the amount of interfering peaks due to humic substances that could accumulated due to the preconcentration step and prevent quantification of polar phenolic compounds in environmental water samples. This method was used to determine the phenolic compounds in tap and river water and superiority to the US EPA 625 method in its enrichment factor, pretreatment time, recoveries, and detection limit. The limits of detection were in the range of $0.3-0.9\;{\mu}g/L$ in tap water sample.

• Bulletin of the Korean Chemical Society
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• v.30 no.1
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• pp.35-42
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• 2009

Headspace micro solid phase extraction using mulberry paper bag (HS-MPB-$\mu$-SPE) has been developed and validated for the analysis of volatile flavor compounds from five spice by gas chromatography-mass spectrometry (GC/MS). HS-MPB-$\mu$-SPE was performed with adsorbent particles enclosed inside a mulberry paper bag. Four different kinds of adsorbents such as Tenax TA, Porapack Q, dimethylpolysiloxane and polyethylene glycol were tested. The extraction solvents compared were petroleum ether, methylene chloride, and chloroform. Better results were obtained when Tenax TA and petroleum ether were used. The limit of detection (LOD) and the limit of quantitation (LOQ) were in the range of 1.3 ng/mL and 4.3 ng/mL, respectively, for o-cymene as a model compound of monoterpene. Proposed method showed good reproducibility (3.3%, RSD) and good recoveries (94.0%). The HS-MPB- μ-SPE is very simple to use, inexpensive, rapid, requires small sample amounts and solvent consumption. Because the solvent for extraction is reduced to only a very small volume (0.6 mL), there is minimal waste or exposure to toxic organic solvent and no further concentration step. This method allows successful characterization of the headspace in contact with the five spice sample. Strong trans-anethole from star anise or fennel is a characteristic flavor of five spice powders. HS-MPB-$\mu$-SPE combined with GC/MS can be a promising technique for the broad spectrum measurement of volatile aroma compounds from solid spices.

• Analytical Science and Technology
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• v.28 no.6
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• pp.370-376
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• 2015

An analytical method for determining phenol considered priority pollutants of the US EPA and precursor of toxic phenolic compounds by solid-phase extraction (SPE) and high performance liquid chromatographic systems (HPLC) equipped with fluorescence and mass selective detectors have been developed. The SPE process for sample preconcentration was performed on a commercially available Oasis HLB cartridge packed with polymeric sorbents. The effect of pH, elution solvent, and elution volume on the recoveries of the analytes were investigated with HPLC/FLD. Average recovery of >87.0% was achieved with 60 mg sorbents using 5 mL of methanol as an elution solvent at pH=3.

• Journal of the Korean Society of Tobacco Science
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• v.28 no.2
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• pp.152-157
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• 2006

A new procedure has been developed for the quantitation of aromatic amines in mainstream cigarette smoke. Two solid-phase extraction (SPE) clean up steps, using a different retention mechanisms, are required to process the samples. The first step used a cation-exchange cartridge, followed by a second step that used a cartridge with a hydrophobic retention character. The aromatic amines eluted from the second SPE cartridge are derivatized with pentafluoropropionic anhydride. This new method have advantages over other reported techniques, being sensitive, robust, and easily automated. The detection limits were ranged from 0.12 ng/mL for 1-aminonaphthalene to 0.16 ng/mL for 3-aminobiphenyl and the recoveries were from 97 to 106%. Compared with other reports for analysis of 2R4F reference cigarette, this method shows a close analytical data and good repeatability.

• Analytical Science and Technology
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• v.19 no.5
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• pp.441-448
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• 2006

11-nor-9-carboxy-${\Delta}^9$-tetrahydrocannabinol (THCCOOH) is the major metabolite of tetrahydrocannabinol (THC) which is the primary psychoactive component of marijuana. It is also the target analyte for the discrimination marijuana use. A method using solid-phase extraction (SPE) and gas chromatography/mass spectrometry (GC/MS) was developed for the determination of THCCOOH in human urine. Urine samples (3 mL) were extracted by SPE column with a cation exchange cartridge after basic hydrolysis. The eluents were then evaporated, derivatized, and injected into the GC/MS. The limits of detection (LOD) and quantitation (LOQ) were 0.4 and 1.2 ng/mL, respectively. The response was linear with a correlation coefficient of 0.999 within the concentration range of 1.2 (LLE 1.3)~50.0 ng/mL. The precision and accuracy were stable within 1.20% and the recovery was 83.6~90.7%. The recovery of SPE method was lower than that of liquid-liquid extraction (LLE), but there were no apparent differences in LOD, LOQ, precision and accuracy between the two methods. While SPE method is used as a very effective and rapid procedure for sample pretreatment, and clean extracts, LLE method was not suitable for the extraction procedure of THCCOOH in urine. The applicability of the method was proven by analyzing a urine samples from a marijuana abusers.

• Korean Journal of Food Science and Technology
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• v.42 no.3
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• pp.257-262
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• 2010

Patulin, a secondary metabolite of mold, is commonly found in rotten apples. Many countries regulate patulin at levels ranging from 30 to $50\;{\mu}g/L$. Most analytical methods for removing patulin from apple juice include liquid-liquid extraction (LLE), which is time and labor intensive. To replace the LLE method, a solid-phase extraction (SPE) method has been developed for apple juice and unfiltered apple juice. A portion of the test sample was applied to a macroporous copolymer cartridge and washed with 5 mL of 1% sodium bicarbonate, followed by 5 mL of 1% acetic acid. Patulin was eluted with 5 mL of 2% acetonitrile in anhydrous ethyl ether. The mobile phase was tetrahydrofuran in water (0.8:99.2) and was detected with a UV detector at 276 nm. Recoveries ranged from 95 to 101% in test samples, and the minimum detectable level was 30 ppb. Because this SPE method is fast, easy, reliable, and inexpensive, it could be applicable for companies or analytical agencies to analyze patulin concentrations in apple juice.

• Food Science of Animal Resources
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• v.28 no.5
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• pp.637-644
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• 2008

Four different extraction and purification methods were evaluated to determine the heterocyclic amines (HCAs) in fried pork patties. Pork patties were cooked in the teflon-coated electric frying pan at $230^{\circ}C$ for 8 min per side. HCAs in the fried pork patties were extracted and purified using four different solid-phase extraction (SPE) methods and quantitated by LC-MS (API-ESI). Recovery of four different extraction and purification methods was evaluated by comparing the HCAs amounts quantified by the standard addition method. Validation of extraction and purification methods for fried pork patties was determined to establish accurate sample preparation. The recoveries of HCAs from different SPE methods were calculated. The recovery yields were 15.7-68.7% (Polar amine group) and 25.0-74.7% (less-polar amine group) in method A. Method D provided recovery yields ranging from 14.1% to 68.7% in polar amine groups and from 3.0% to 72.3% in less-polar amine groups, respectively. Modified procedures of Method A and D were the most suitable extraction and purification method for HCAs analysis from fried pork patties.

• Journal of the Korean Magnetic Resonance Society
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• v.15 no.1
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• pp.14-24
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• 2011

We have performed Liquid Chromatography-Solid Phase Extraction-NMR (LC-SPE-NMR) analysis for liquid crystalline mixture and elucidated the structures of selected components by NMR spectra. Combining the results of one-dimensional 1H experiments as well as homonuclear and heteronuclear two-dimensional experiments, we could analyze the molecular structure of the liquid crystal singles whose structure had not been interpretable by mass spectrometry alone.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.2
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• pp.75-83
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• 2013

We applied a sensitive method based on on-line solid-phase extraction (SPE) and liquid chromatography/mass spectrometry (LC/MSD) using an electrospray interface for the determination of eleven perfluorinated compounds (PFCs) in water. The on-line connection suppressed the target loss by keeping the cartridge from drying, which resulted in improvement of the recovery and saving of the analytical time. For the on-line solid-phase extraction of 10 mL water samples, recoveries were between $80.4{\pm}5.2%{\sim}109.5{\pm}1.4%$ and limit of quantification (LOQ) were 3.6~15.9 ng/L for the PFCs. The total PFCs concentrations of the tributaries and main stream of Nakdong River water samples were in the range of $8.0{\sim}678.6{\mu}g/L$.