• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2004.04a
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• pp.370-375
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• 2004

KMnO$_4$에 의한 TCE 용액의 분해에서 Headspace를 가진 반응 용기는 liquid sample을 headspce의 관측값으로 반응의 특성을 나타낼 수 없다. 이런 특성에 의해 in-situ KMnO$_4$ 이용은 TCE의 제거 효율에서 자연적인 휘발을 고려해야한다. 1:2.45 몰비에서 liquid sample의 결과 반감기는 약 80분이고 160분에 약 67%의 제거율을 보인다. 1:12.27 몰비의 경우 반감기는 10분이고 90분에 95%의 제거효율을 보인다.

• Asian Journal of Atmospheric Environment
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• v.11 no.1
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• pp.54-60
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• 2017

Quantifying the trace elements in infinitesimal ambient liquid samples (e.g., single raindrop, cloud/fog water, and the soluble fraction extracted from the particles collected for a short time) is an important task for understanding formation processes, heating/cooling rates, and their health hazards. The purpose of this study is to employ an in-air micro PIXE system for quantitative analysis of the trace elements in a thimbleful of reference liquid sample. The bag type liquid sample holder originally designed with $10{\mu}m$ thick $Mylar^{(R)}$ film retained the original shape without any film perforation and apparent peaks of film blank by the end of the analysis. As one of tasks to be solved, the homogeneity of the elemental distribution in liquid reference species was verified by the X-ray line profiles for several references. It was possible to resolve the significant peaks for whole target elements corresponding to the channel number of micro-PIXE spectrum. The calibration curves for the six target elements (Si, S, Cl, Fe, Ni, and Zn) in standard solutions were successfully plotted by concentration (ppm) and ROI of interest net counts/dose (nC).

• Bulletin of the Korean Chemical Society
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• v.26 no.6
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• pp.947-951
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• 2005

Rotating compensator multichannel spectroscopic ellipsometry has been employed to determine the optical functions of various liquids used in chemistry. We attempted three different measurement configurations: (1) air-liquid interface, (2) prism-liquid interface, and (3) liquid-sample interface. In prism-liquid interface, we found that the prism surface had roughness and it should be considered in analysis for accurate results. In liquidsample interface, we had much higher reflection, better sensitivity, and less limitation compared to the other two configurations when crystalline silicon was used as reference sample. We discuss the merit of each configuration and present the optical functions of various liquids. Also we demonstrate Bruggeman effective medium theory to determine the optical properties of mixed liquid.

• Mass Spectrometry Letters
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• v.7 no.1
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• pp.26-29
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• 2016

Simultaneous determination of three corticosteroids (clobetasol propionate, betamethasone dipropionate, fluticasone propionate) in moisturizers was performed by using liquid chromatography (LC) coupled with tandem mass spectrometry (MS/MS). Sample preparation was conducted by the liquid-liquid extraction (LLE). Moisturizers include emulsifying agent and it forms micelles. In order to improve the extraction efficiency of corticosteroids trapped in micelle, newly developed-optimized extraction conditions which can remove the matrix effect from moisturizers was applied with various pH conditions in LLE extraction stage of sample preparation. Thus, the addition of 10 μL of 1 M HCl into moisturizers sample before extraction could improve the extraction efficiency. For the quantitative analysis, SRM table that contained specific transition of all of target corticosteroids was created. The developed method was validated for linearity, accuracy, precision, limit of detection (LOD), limit of quantization (LOQ) and recovery. Over the 0.99 r² value was obtained in calibration standard range. Effective accuracy and precision were also obtained. LODs were below 31 ng/mL and LOQs were estimated below 94 ng/mL for all corticosteroids tested.

• Analytical Science and Technology
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• v.29 no.1
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• pp.29-34
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• 2016

This study explores the means by which MX can be effectively extracted from chlorinated water 3-Chloro-4-(dichloromethyl)-5-hydroxy-2(5H)-furanone (MX), a potent mutagen commonly found in chlorinated drinking water at concentrations of up to a few hundred ng/L, was quantitatively determined using sample enrichment followed by liquid-liquid extraction (LLE), derivatization to methylated form, and analysis with GC-MS. A 4-L water sample was enriched to a concentration of 0.4 L using a vacuum rotary evaporator at 30 ℃. MX in the water was extracted using ethyl acetate (100 mL × 2) as a solvent and MX in the extract was methylated with 10 % H₂SO₄ in methanol. MX was recovered at a rate of 73.8 %, which was higher than that (38.1 %) for the resin adsorption method. The limit of quantification and repeatability (as relative standard deviation) were estimated to be 10 ng/L and 2.2 %, respectively. This result suggested that LLE can be used for the determination of MX in chlorinated water as an alternative to more time-consuming resin adsorption method.

• Bulletin of the Korean Chemical Society
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• v.27 no.2
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• pp.231-236
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• 2006

A novel sample pretreatment technique, headspace hanging drop liquid phase microextraction (HS-LPME) was studied and applied to the determination of flavors from solid clove buds by gas chromatography-mass spectrometry (GC-MS). Several parameters affecting on HS-LPME such as organic solvent drop volume, extraction time, extraction temperature and phase ratio were investigated. 1-Octanol was selected as the extracting solvent, drop size was fixed to 0.6 $\mu$L. 60 min extraction time at 25 ${^{\circ}C}$ was chosen. HS-LPME has the good efficiency demonstrated by the higher partition equilibrium constant ($K_{lh}$) values and concentration factor (CF) values. The limits of detection (LOD) were 1.5-3.2 ng. The amounts of eugenol, $\beta$-caryophyllene and eugenol acetate from the clove bud sample were 1.90 mg/g, 1.47 mg/g and 7.0 mg/g, respectively. This hanging drop based method is a simple, fast and easy sample enrichment technique using minimal solvent. HSLPME is an alternative sample preparation method for the analysis of volatile aroma compounds by GC-MS.

• Bulletin of the Korean Chemical Society
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• v.31 no.10
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• pp.2813-2818
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• 2010

A novel method was developed for the speciation of chromium in natural water samples based on homogeneous liquid-liquid extraction and determination by flame atomic absorption spectrometry (FAAS). In this method, Cr(III) reacts with a new Schiff's base ligand to form the hydrophobic complex, which is subsequently entrapped in the sediment phase, whereas Cr(VI) remained in aqueous phase. The Cr(VI) assay is based on its reduction to Cr(III) by the addition of sodium sulfite to the sample solution. Thus, separation of Cr(III) and Cr(VI) could be realized. Homogeneous liquid-liquid extraction based on the pH-independent phase-separation process was investigated using a ternary solvent system (water-tetrabutylammonium ion ($TBA^+$)-chloroform) for the preconcentration of chromium. The phase separation phenomenon occurred by an ion-pair formation of TBA and perchlorate ion. Then sedimented phase was separated using a $100\;{\mu}L$ micro-syringe and diluted to 1.0 mL with ethanol. The sample was introduced into the flame by conventional aspiration. After the optimization of complexation and extraction conditions such as pH = 9.5, [ligand] = $1.0{\times}10^{-4}\;M$, [$TBA^+$] = $2.0{\times}10^{-2}\;M$, [$CHCl_3$] = $100.0\;{\mu}L$ and [$ClO_4$] = $2.0{\times}10{-2}\;M$, a preconcentration factor (Va/Vs) of 100 was obtained for only 10 mL of the sample. The relative standard deviation was 2.8% (n = 10). The limit of detection was sufficiently low and lie at ppb level. The proposed method was applied for the extraction and determination of chromium in natural water samples with satisfactory results.

• Korean Journal of Veterinary Research
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• v.43 no.3
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• pp.393-398
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• 2003

Simple and rapid sample preparation method for trace elements in foods of animal origin using ultra high pressure microwave digestion system (UHP/MDS) and inductively coupled plasma atomic emission spectrometer (ICP/AES) were developed. 1. For the digestion of sample using UHP-MDS, 20% nitric acid (v/v) was the most suitable solvent for the determination of trace elements in foods of animal origin. 2. The optimal digestion conditions for UHP-MDS were as follows: final temperature $180^{\circ}C$, final pressure 400 PSI, and magnetic power 900 W in the solid sample. For the liquid sample final temperature $170^{\circ}C$, final pressure 300 PSI and magnetic power 700 W were optimal conditions. 3. As result of interlaboratory test, the average recovery rate of the for solid sample were 88.3~99.1% for As, 82.4~93.3% for Cd, 89.2~101.2% for Hg and 86.5~93.8% for Pb, respectively. In liquid sample, it were 87.0~96.8% for As, 80.9~96.6% for Cd, 87.5~91.2% for Hg and 91.4~95.5% for Pb, respectively. 4. The average coefficient variation rate were 3.3~15.9% for solid sample and 2.9~10.8% for liquid sample.

• Korean Journal of Veterinary Service
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• v.36 no.4
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• pp.273-281
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• 2013

This study investigated the effects of the alkaline detergent and acid rinse used for cleaning milking machines on the eight commercially available teatcup liner materials. The sample liners prepared for use in the clean-in-place process were analyzed by ultraviolet spectrophotometer, ion chromatography and liquid chromatography. Among the eight liner materials, the ultraviolet spectra of 3 sample liners were shown to have a similar peak shape after cleaning, but the ultraviolet spectra peak shape of 5 sample liners was noticeably changed. No products were detected by ion chromatography in any of the liner materials used in this study. When the liner materials were only treated with alkaline detergent, some additional peaks were observed using liquid chromatography which indicate the creation of molecular substance and elution from liner materials, however, these peaks disappeared when the liner materials were cleaned with the acid rinse. Therefore, we propose that an acid rinse should be applied, after cleaning the milking machine with the alkaline detergent.

• Culinary science and hospitality research
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• v.22 no.5
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• pp.95-105
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• 2016

The purpose of this study is to identify the possibility of developing new jelly product with healthy function by the physio-chemical analysis and sensory test of jelly sample groups adding each 20~80% of squeezed Indian spinach liquid. Sugar contents of squeezed Indian spinach liquid was $3.4^{\circ}Brix$. From chromatography, L-value has been decreased by increasing the adding rate of squeezed Indian spinach liquid, and both a-value (redness) and b-value (yellowness) have shown similar trend. According to the measuring result of squeezed Indian spinach liquid the DPPH radical scavenging activity was 15.67 mg/mL, and its total polyphenol contents was 7.00 mg/g. By increasing squeezed Indian spinach liquid, the DPPH radical scavenging activity and total polyphenol contents have shown increasing tendency. Among textures of squeezed Indian spinach liquid, for hardness, sample group of 20% adding was the highest by 4.27%, and for adhesiveness the sample group of 20% adding was the highest by 2.48%, and the lowest was sample group of 80% adding with 0.91%. From the result of sensory test the sample group adding 40% of squeezed Indian spinach liquid has been appraised the most highly in color, scent, sweet taste, chewiness, moistness, and general preference. According to the above results, it is understood that the 40% adding rate of squeezed Indian spinach liquid, when producing jelly, would be the most compatible rate of adding.