• Analytical Science and Technology
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• v.13 no.5
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• pp.636-645
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• 2000

A method is described for the determination of organotins in water samples by GC/MS. Optimized derivatization methods for ethylation and hydrogenation of organotins were surveyed according to various reaction conditions such as time, pH and concentration of reagents. The organotins were extracted with n-hexane in presence of 0.1% tropolone and hydrogenated with sodium borohydride. Extraction recoveries of organotins with hydrogenation were in the range of 61-112%. After ethylation, organotins in water samples were extracted by liquid-liquid extraction (LLE) and solid-phase extraction (SPE). Using LLE, extraction recoveries were in the range of 74-113%. The recoveries ranged from 61-97% in the case of SPE with styrene-divinylbenzene copolymers. Method detection limits of hydrogenated and ethylated organotins ranged from 0.05 to 0.5 ng/ml and from 0.02 to 0.05 ng/ml, respectively.

• Analytical Science and Technology
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• v.21 no.5
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• pp.412-423
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• 2008

A procedure based on solid-phase extraction (SPE) followed by liquid chromatography-tandem mass spectrometry has been developed for the simultaneous analysis of 55 basic drugs in equine urine. The test scope covers diversified classes of drugs including some ${\beta}$-blockers, ${\beta}$-agonists, antihypotensives, CNS stimulants, sedatives, tranquilizers, antidepressants, antihypertensives and so on. LC-MS/MS separation and quantification was carried out in positive electrospray ionization and multiple reaction monitoring (MRM) mode. Four different brands of mixed mode cation exchange SPE sorbents; UCT XTRACT$^{(R)}$ XRDAH, Supelco DSC-MCAX$^{(R)}$, Varian Bond Elut Certify$^{(R)}$ and Waters Oasis$^{(R)}$ MCX were compared. The UCT XTRACT$^{(R)}$ XRDAH sorbent provided the best results in the preconcentration of samples, yielding relative recoveries higher than 80% except for terbutaline (41.3%), salbutamol (71.5%), heptaminol (70.7%), phenylpropanolamine (66.3%). Detection limits of the target drugs provided by the proposed analytical procedure were between 0.2~8.3 ng/mL.

• Analytical Science and Technology
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• v.21 no.3
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• pp.191-200
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• 2008

Pharmaceuticals and personal care products (PPCPs) are emerging contaminants in aquatic environmental samples. Therefore, it required rapidly and certainly analytical method for pharmaceuticals which are existed in environment. In this study, Liquid chromatography/tandem mass spectrometry (LC-MS/MS) with electrospray ionization (ESI) was used to measure the concentrations of 7 pharmaceuticals (quinoxaline-2-carboxylic acid, acetylsalicylic acid, diclofenac-Na, naproxen, ibuprofen, mefenamic acid, talniflumate) from environmental water or aquatic samples simultaneously. Effective sample clean-up by solid-phase extraction (SPE) prior to LC-MS/MS analysis is necessary. For further purification, Mixed Cation eXchange (MCX) and Hydrophilic-Lipophilic Balance (HLB) solid-phase extraction (SPE) cartridges were used to eliminate the remaining interferences. LODs (Limits of Detection) and MDLs (Method Detection Limits) for the spiked sample in fresh water were in the range of 0.05~1.50 pg/mL and 0.17~4.90 pg/mL, respectively. The absolute recovery in the concentration of 1.0 ng/mL were between 81.9 and 116.3%. The acidic pharmaceuticals were detected in concentrations of 0.018~16.925 ng/mL in aquatic environmental samples.

• Journal of the Korean Society for Marine Environment & Energy
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• v.3 no.3
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• pp.34-40
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• 2000

A multisample extraction device was newly designed for efficient extraction of dissolved lipophillic organic compounds from sea water sample. This device allowed extraction of organic compounds from up to 96 sample at a time using 96 multifolder on the principle of solid phase extraction with commercially available octadecyl silane (ODS) cartridges. The recovery yield of the new divice was higher than 90 % while that of conventional liquid-liquid extraction process are only 60 - 70 %. The amount of solvent required for the new device could be reduced to less than 20㎖ per 1ℓ of sample while 1 - 2 ℓ of solvent were used in the conventional liquid-liquid extraction process. The usefulness of this novel method was demonstrated with sea water samples collected from Yellow sea, and the qualitative and quantitative analyses results of the dissolved hydrocarbon showed this method was superior to that of conventional liquid-liquid extraction process in efficiency and reliability.

• Journal of Convergence for Information Technology
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• v.11 no.11
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• pp.239-247
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• 2021

This paper aims to increase functionality and competitiveness through fermentation of rice bran, which is used as a raw material for alternative foods and cosmetics. Cytotoxicity and anti-inflammatory effects were confirmed using rice bran extract fermented with Saccharomycopsis fibuligera A8 isolated from Nuruk. In the case of cytotoxicity, cytotoxicity was shown at 100 ㎍/mL for rice bran extracts, but cytotoxicity was not shown for fermented rice bran extracts. Meanwhile, as a result of confirming anti-inflammatory effects through inflammatory indicators such as nitric oxide, TNF-α, IL-1β, and IL-6, rice bran extracts showed anti-inflammatory effects at concentrations of 100 ㎍/mL or higher only nitric oxide and TNF-α. And fermented rice bran extracts exhibited anti-inflammatory effects at concentrations of 25 ㎍/mL, 25 ㎍/mL, 50 ㎍/mL, and 50 ㎍/mL, respectively, exhibiting anti-inflammatory effects in lower concentration. Meanwhile, as a result of testing the cytotoxicity and anti-inflammatory effects of heat-killed S. fibuligera, it was found that the heat-killed S. fibuligera showed anti-inflammatory effect in fermented products.

• Journal of Environmental Science International
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• v.12 no.1
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• pp.81-86
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• 2003

The study was carried out to evaluate the new analytical method of phthalate esters(diethylphthalate, di-n-butylphthalate, butylbenzylphthalate, bis(2-ethylhexyl)phthalate), one of the endocrine disruptors, which were performed by GC/MS-SIM(selected ion monitoring). The phthalate esters were extracted from water samples using solid-phase extraction on $C_{18}$ columns. It investigated that the extraction recovery rate of phthalate esters with different solvents and solvent volume. The optimal solvent was dichloromethane and proper volume of dichloromethane for recovery of phthalate esters was 4 mL. There were good linearities(above $R^2$=0.9975) in the range 0.01~0.50mg/L, and the detection limits were below 0.01~0.03$\mu\textrm{g}$/L. The recovery rates, RSD and MDLs for phthalate esters were 80~114%, 5.0~8.1% and 0.03~0.11$\mu\textrm{g}$/L, respectively. This method shows a good precision of phthalate esters.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.195-198
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• 2005

A solid-phase microextraction and gas chromatography-mass spectrometry for the extraction and analysis of methyl-tert-butyl ether has been described. methyl-tert-butyl ether was extracted from aqueous solution using SPME fiber coated polydimethylsiloxane and analysed by GC-MS with capillary column. Extraction parameters and chromatographic separation conditions were optimized. The applied method represented good analytical performance in terms of precision (3-8%, RSD) and accuracy(93-102%, mean recovery) with a method detection limit of 0.03 ppb.

• Journal of Environmental Science International
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• v.24 no.1
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• pp.1-7
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• 2015

The solid-phase extractant PS-D2EHPA/TBP was prepared by immobilizing two extractants D2EHPA and TBP in polysulfone (PS). The prepared PS-D2EHPA/TBP was characterized by using fourier transform infrared spectrometer (FTIR) and scanning electron microscopy (SEM). The removal of Cu(II) from aqueous solution was investigated in batch system. The experiment data were obeyed the pseudo-second-order kinetic model. Equilibrium data were well fitted by Langmuir model and the removal capacity of Cu(II) by solid extractant PS-D2EHPA/TBP obtained from Langmuir model was 3.11 mg/g at 288 K. The removal capacity of Cu(II) was increased according to increasing pH from 2 to 6, but the removal capacity was decreased below pH 3 remarkably.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.427-431
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• 1997

A simultaneous and rapid gas chromatographic determination of organophosphorus, organo-chlorine, carbamate, and pyrethroid pesticides in polished rice was developed. The pesticides were extracted from samples with acetone by automated soxhlet apparatus and this extract was evaporated to dryness. The residue was dissolved in hexane, the solvent was applied to a Sep-Pak florisil catridge, was eluted with 50% ethyl acetate in n-hexane, and was injected to dual GC-ECD/NPD system. This simple method affords a high recovery of hydrophilic pesticides, allows rapid analysis, and is cheap to perform. Except for dichlorvos and captan, recoveries of 46 pesticides were over 60%.

• Korean Journal of Food Science and Technology
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• v.30 no.4
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• pp.721-727
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• 1998

An analytical method for simultaneous and rapid determination of organophosphorus, organochlorine, carbamate, and pyrethroid pesticides in polished rice was developed. The analysis is performed by gas chromatograph with mass selective detector (GC/MSD) in selected ion monitoring (SIM) mode. Pesticides were extracted from samples with acetone by automated Soxhlet apparatus and this extract was evaporated to dryness for the analysis. The residue was dissolved in hexane, followed by a treatment with a Sep-Pak florisil catridge. Pesticides were positively confirmed by GC/MS, retention times, and ion ratios. This analytical method allows a rapid, reliable, and a good recovery of hydrophilic pesticides. Except far captafol, captan, dichlofluanid and dichlorvos, recoveries of 42 pesticides were over 70%.