• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.04a
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• pp.37-40
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• 2011

화재현장에서는 화재의 원인으로 간주되는 여러 가지 증거물이 발생한다. 이러한 증거물을 분석하기 위한 수단으로 GC/MS의 역할은 아주 크며, 이를 이용한 증거물의 분석에 관한 표준으로 ASTM 1618-10과 전처리법을 소개한다. 또한 전처리법에 따른 여러 가지 종류의 유류의 특성을 알아보고 유류 성분을 포함한 화재증거물의 실제 사례를 들어 보겠다. 아울러 화재현장에서의 가연물로 추정되는 물질에 대하여 열분해를 통한 GC/MS 분석 사례도 제시하여 본다.

• Journal of Korean Society of Environmental Engineers
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• v.35 no.7
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• pp.485-494
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• 2013

An efficient extraction method was developed for the analysis of 16 perfluorinated compounds (PFCs) in fish samples. We compared the recoveries from the Ion-Pairing Extraction (IPE), Liquid-Liquid Extraction (LLE), Solid-Phase Extraction (SPE), IPE + SPE method with varying the injection time of the internal standard. As a result, IPE method with the internal standard before extraction was evaluated as the most effective pretreatment method. The RPM (Revolution Per Munite) and pH in IPE-before method were additionally adjusted and the more efficient pretreatment method was established. The total 33 fish samples including liver and gut samples were collected from Korean markets and analyzed PFCs with developed pretreatment method of this study. Total 16 PFC levels in fish samples ranged from ND to 1.67 ng/g with 100% detection frequency. The average PFCs concentrations of muscle, liver and gut samples from fish were compared and showed the following trend: liver (17.8 ng/g) > gut (13.3 ng/g) > muscle (1.67 ng/g). The PFC levels in fish samples were similar or lower than other available previous results of foreign studies.

• Journal of the Microelectronics and Packaging Society
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• v.22 no.4
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• pp.57-63
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• 2015

In order to prepare a low-cost conductive filler material possessing improved anti-oxidation property, Ag-coated Cu flakes were fabricated and the effects of an applying method of ammonium-based pretreatment solution on the Cu flakes were analyzed. The pretreatment solution was used to remove the surface oxide layer on Cu flake. During a single-stage pretreatment process, hole-shaped defects were formed on the flake surface during the pretreatment after 2 min, and the number and size increased in proportion to the pretreatment time. In the case that Ag plating solution was injected in the pretreatment solution after the pretreatment for 2 min, the defects were also formed during Ag plating. In contrast, the defects tremendous decreased in the case that the pretreatment solution was removed after the first pretreatment for 2 min and the Ag plating proceeded after the second pretratment using a low concentration pretreatment solution. As the final result, the 15 wt% Ag-coated Cu flake sample which was fabricated using the single-stage pretreatment oxidized at $166^{\circ}C$, but the sample fabricated by the double-stage pretreatment oxidized at $224^{\circ}C$, indicating definitely improved anti-oxidation property.

• 한국신재생에너지학회:학술대회논문집
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• 2011.05a
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• pp.177.2-177.2
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• 2011

세계적인 자원고갈과 지구온난화와 같은 환경문제가 발생됨에 따라 대체에너지 개발에 대한 연구가 활발히 이루어지고 있다. 섬유소 기질을 이용한 바이오에탄올 생산은 세계적으로 막대한 자원이 있으며 광합성에 의해 재생산되는 무한한 재원으로서 환경적으로도 대기오염물질을 적게 배출하여 유용한 에너지원으로 각광받고 있다. 하지만 섬유소 기질은 cellulose, hemicellulose, lignin과 같은 고분자 화합물이 유기적으로 결합된 단단한 결정구조로 이루어져 있어 이를 분해하여 원하는 물질을 얻기 위해서는 전처리 과정이 필요하다. 전처리 공정은 바이오에탄올을 생산하는 당화 및 발효공정의 효율 및 반응시간 단축에 기여하며, 특히 섬유소 기질일 경우에는 필수불가결한 공정이다. 전처리 공정은 물리적, 화학적, 생물학적 방법으로 나누어지며, 이러한 방법들 중 기질의 특성과 처리효율에 따라 기술들을 병합하여 사용하기도 한다. 이에 본 연구에서는 산 처리, 암모니아 처리, 과산화수소 처리 및 효소를 이용한 생물학적 처리를 단독 또는 병행하여, 전환된 당 성분 및 함량을 조사함으로서 섬유소계 기질인 채소 음식물류 쓰레기를 대상으로 바이오에탄올을 경제적으로 생산하기 위한 적합한 전처리법을 검토하였다. 전처리 방법별 당화율을 살펴보면, 산 처리와 암모니아-과산화수소-계면활성제 처리가 각각 65.3 % 및 65.7 %로 가장 높았으며, 과산화수소 처리는 16.2 %로 가장 낮았다. 반면 전처리 공정 없이 효소를 이용한 당화만을 실시한 경우에는 4.3 %의 낮은 당화율을 나타내었다. 섬유소계 기질의 전처리 효율을 향상시키기 위해 첨가하는 계면활성제의 효과는 암모니아-과산화수소 및 암모니아-과산화수소-계면활성제 처리의 당화율을 비교한 결과, 뚜렷한 효과를 확인할 수 없었다. 전처리 방법별 당의 성분 및 함량을 비교한 결과 육탄당은 암모니아-과산화수소-계면활성제 전처리에서 가장 많이 검출되었다. 오탄당은 산 처리 후 그 함량이 현저히 높았으며, 오탄당 중 xylose의 함량이 60.49 mg/g로 가장 많이 차지하고 있었다. 이 결과로부터 전처리 방법에 관계없이 당화율은 유사한 수준을 보이지만, 당화된 당의 성분 및 함량에는 큰 차이가 있음을 알 수 있었다. 이당류의 경우 과산화수소 및 암모니아-과산화수소 처리를 제외한 나머지 전처리 방법에서 유사한 수준을 나타내었다. 암모니아 처리 및 과산화수소 처리를 순차적으로 병행한 암모니아-과산화수소 처리에서는 각각의 처리시보다 육탄당의 함량은 증가하였으나 암모니아 처리시보다 이당류의 함량은 감소한 것으로 나타났다.

• Journal of Food Hygiene and Safety
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• v.36 no.1
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• pp.93-99
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• 2021

This study was undertaken to compare the efficacy of different sample preparation (stomaching, pulsifying, and sonication) and DNA extraction methods (boiling and commercial kit) for detection of enterotoxin-producing Clostridium perfringens from produce by polymerase chain reaction (PCR). Each produce type was inoculated at concentrations of 102, 103, 104, 105, 106, and 107 spores/g. Produce inoculated with spores was treated with three sample preparation methods, and DNA was extracted by boiling method and a commercial kit, followed by PCR. The detection limit of stomached samples was lower than that of pummeled and sonicated samples by 10-100 times. Moreover, the DNA extraction efficiency of the commercial kit was found to be superior to that of boiling. In particular, the PCR efficiency of cherry tomato and perilla leaf samples was greatly affected by sample preparation and DNA extraction method. These data suggest that DNA extraction with a commercial kit after pulsification is an optimum sample preparation method for detection of C. perfringens by PCR.

• Journal of Food Hygiene and Safety
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• v.31 no.5
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• pp.311-318
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• 2016

Azorubine is a synthetic tar color containing azo-bond in the molecular structure. This food colorant has been allowed to be used for beverages, cheese and dried fruits in the European Union and for some food in Australia. Even though it is applicable as a food color in many countries, this compound has not been permitted in Korea so far as a food additive. Thus, this study was performed to establish an analysis method for azorubine in Korea by comparison of three HPLC analysis methods for azorubine and other azo-compounds which are officially used in the European Food Safety Authority (EFSA, EU), the Food Standard Agency (FSA, England) and the National Institute of Food and Drug Safety Evaluation (NIFDS, Korea). The analysis method of the FSA for azorubine showed the best linearity ($r^2=0.999$), limit of detection (LOD, $0.07{\mu}g/mL$), limit of quantification (LOQ, $0.20{\mu}g/mL$), precision (0~0.5%) and accuracy (98.6~100.7%) among tested HPLC methods using a C-18 column and diode array detector (DAD) with ammonium acetate solution and acetonitrile as an eluent solution. Finally selected method of FSA was further verified by inter-day and intra-day experiments with linearity, LOD, LOQ, precision and accuracy. Recovery test showed the recover ratios of 97~103%, 95~101%, and 93~102% in beverages, breads/snacks and other foods, respectively. Inter-laboratory test represented the absolute value of z-score of less than 2 which means satisfactory levels in this test. Selected method of FSA showed reliable analytical results in application test using food samples collected in commercial markets in Europe.

• The Korean Journal of Pesticide Science
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• v.18 no.4
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• pp.278-295
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• 2014

Fast and accurate multi-residue pesticides inspecting method needs in Agro-Fishery Products Inspection Center. So, We tried to seek the optimum method using GC-TOF/MS, GC-ECD, GC-NPD after QuEChERS sample preparation. In GC-TOF/MS, 138 kinds of pesticide were spiked at 0.3 and $0.5{\mu}g/g$for the identification and quantification in lettuce sample. Recoveries of 77 pesticides were between 70 and 130% with RSD (relative standard deviation lower than 20% at $0.3{\mu}g/g$. In GC-ECD, NPD, 146 kinds of pesticide were spiked for the identification and quantification in lettuce. Recoveries of 61 species were between 70 and 130% with lower than 20%. These results indicated that GC-TOF/MS, GC-ECD, NPD analysis with the QuEChERS sample preparation can be partly applied to multi-residue pesticides in vegetables.

• Proceedings of the Korea Society for Energy Engineering kosee Conference
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• 2010.04a
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• pp.158-158
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• 2010

• The Korean Journal of Pesticide Science
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• v.15 no.4
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• pp.417-433
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• 2011

The study tested QuEChERS (quick, easy, cheap, effective, rugged and safe) sample preparation and HPLC-MS/ MS analysis for measurement of pesticide residues in fruit and vegetable. 240 kinds of pesticides spiked at three levels of 90, 45, 9 ng/g in lettuce and apple. For QuEChERS sample preparation, graphitized carbon black (GCB) was used for only lettuce in dispersive-SPE as absorbent. Matrix-matched standard calibration was used for quantitative analysis of HPLC-MS/MS. 218 pesticides (91%) in apple and 207 pesticides (86%) in lettuce showed recoveries in the range of 70~120% with $RSD{\leq}20%$. The lowest calibrated level (LCL) were 4.5 ng/g for 192 pesticides, 9 ng/g for 42 pesticides, 45 ng/g for 3 pesticides and 3 pesticides were not detected at all concentration levels. The results showed that the QuEChERS sample preparation and HPLC-MS/MS analysis can be applied to multi-residue analysis of pesticides in vegetables and fruits.

• Journal of Korean Society of Water and Wastewater
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• v.32 no.6
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• pp.559-572
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• 2018

The aim of this study was to evaluate pretreatment methods for 27 pharmaceuticals and personal care products (PPCPs) in various sewage samples using a modified quick, easy, cheap, effective, rugged, and safe (QuEChERS) and online solid-phase extraction with LC-MS/MS. Extraction efficiencies of PPCPs in the solid phase under different experimental conditions were evaluated, showing that the highest recoveries were obtained with the addition of sodium sulfate and ethylenediaminetetraacetic acid disodium salt dehydrate in acidified conditions. The recoveries of target compounds ranged from 91 to 117.2% for liquid samples and from 61.3 to 137.2% for solid samples, with a good precision. The methods under development were applied to sewage samples collected in two sewage treatment plants (STPs) to determine PPCPs in liquid and solid phases. Out of 27 PPCPs, more than 19 compounds were detected in liquid samples (i.e., influent and effluent) of two STPs, with concentration ranges of LOQ-33,152 ng/L in influents and LOQ-4,523 ng/L in effluents, respectively. In addition, some PPCPs such as acetylsalicylic acid, ibuprofen, and ofloxacin were detected at high concentrations in activated sludge as well as in excess sludge. This methodology was successfully applied to sewage samples for the determination of the target compounds in STPs.