• Applied Biological Chemistry
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• 제45권2호
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• pp.97-100
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• 2002

Phthalate ester는 플라스틱의 물리적 성질, 특히 유연성을 향상시키기 위하여 플라스틱 제품에 첨가하는 가소제이며 내분비계 장애를 일으키는 것으로 추정되는 물질이다. 본 연구에서는 우리나라 한강지류 하천 주변 토양의 phthalate esters의 오염 정도를 gas chromatography-mass spectrometry(GC-MS) 방법으로 분석하였다. 그 결과 예상 오염 지역인 안양천과 서호천, 그리고 예상 청정 지역인 가평천과 남한강 지역에서 채취한 토양시료 모두에서 bis(2-ethylhexyl) phthalate(DEHP)가 일정 수준 검출되었다. 그 오염 수준은 안양천 주변 토양이 113ppb로 가장 높았으며, 서호천 주변 토양이 64 pub,그리고 가평천과 남한강 주변 토양이 약 50 ppb이었다. 따라서 한강 지류 하천 토양의 DEHP오염은 국내 하천 저질의 DEHP오염 수준이 최고 2.04 ppm임을 감안할 때 상대적으로 낮은 수준임을 알 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제30권1호
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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.

• 분석과학
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• 제11권1호
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• pp.36-41
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• 1998

GC-MS를 이용한 사람의 혈중 5-fluorouracil(5-FU)의 정량법이 연구되었다. 5-FU은 isopropanol-ether(20:80) 혼합용매 10ml로서 추출하였고 pentafluoro-benzylation에 의해 유도체화 하였다. 시료주입은 자동으로 수행하였으며 분리에 사용한 칼럼은 비극성 capillary column이었고 검출은 MSD로 하였다. 위의 조건하에서 내인성 물질들의 방해현상은 없었고 검출한계는 0.5 ml의 혈액시료를 사용하였을 때 3 ng/ml이었으며 추출효율은 80%이상을 나타냈다. 5-FU로 항암치료를 받는 환자의 시료 500개중에 혈중 5-FU의 농도 측정에 적용하였으며 이 방법이 우수한 monitoring법임을 알 수 있었다.

• 분석과학
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• 제17권1호
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• pp.29-36
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• 2004

본 연구에서는 토양중에 존재하는 폴리브롬화 디페닐에테르 (polybrominated diphenyl ethers, PBDEs)를 동위원소희석법을 이용한 기체크로마토그래피/질량분석기-선택이온검색법에 의해 검출하는 분석방법을 소개하였다. 토양 중 PBDEs는 속실렛 장치로 추출하고 실리카와 플로리실 흡착제를 이용한 고체상 추출법을 비교하였다. 정제 후 추출물은 기체크로마토그래피/질량분석기-선택이온검색방법으로 분석하였으며, 동위원소로 치환된 4종의 PBDEs를 내부표준물질로 이용한 동위원소 희석법으로 8종의 PBDEs를 정량하였다. 속실렛추출 후 플로리실과 실리카 카트리지를 통한 회수율은 각각 30.8~110.8%, 44.4~110.7%이었다. 이 분석법의 검출한계는 0.04~0.3 ng/g로 나타났다.

• 해양환경안전학회지
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• 제27권6호
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• pp.890-897
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• 2021

최근 선박용 연료유에 대한 황 함유량 규제를 준수하기 위해 저유황유의 수요가 증가하고 있다. 그러나 저유황유를 공급하는 시기, 지역, 회사 별로 그 품질이 상이함에 따라 선내 연료유 저장탱크에서는 과도한 슬러지가 발생하는 등 혼합 안정성에 대한 문제가 제기되고 있다. 따라서 본 연구는 초음파의 캐비테이션 현상을 이용하여 저유황유의 품질 향상을 하고자 하였다. 선내 저장 탱크에서 이종의 연료유가 혼합되는 상황을 모사하기 위해 두 가지 종류의 저유황유(황 함유량 0.5 % 이하 MGO, MDO)를 혼합하여 시료유로 사용하였다. 원료유와 50 wt.% 씩 혼합한 시료유를 120분 동안 초음파 처리하였으며, 40분 주기로 채취된 샘플은 GC/MS 분석을 수행하여 초음파 조사 시간에 따른 시료유의 조성 변화를 분석하였다. 연구결과, 초음파의 캐비테이션 효과로 인하여 화학결합이 깨지면서 MGO 내 존재하는 고분자량 화합물의 감소와 저분자량의 화합물 증가가 관찰되었다. MDO와 혼합유의 경우, 초음파 조사 후 저분자 화합물에 대한 상대 존재비의 부분적 증가가 관찰되었지만 시간과 상대 존재비 사이의 상관관계는 관찰되지 않았다.

• 한국축산식품학회지
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• 제43권3호
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• pp.471-490
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• 2023

In this study, the duck eggs were salted with none or 2.5% and 5.0% (v/v) of liquid smoke (LS), respectively. As a control, samples salted without LS were used. The 2-thiobarbituric acid (TBA) values, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability, and reducing power of the three groups were tested at 0, 7, 14, and 21 and 28 days to determine the effects of LS on the antioxidant activity of treated eggs. In addition, gas chromatography-mass spectrometry (GC-MS) and electronic nose (E-Nose) were used to analyze the volatile flavor components of fresh duck eggs, LS, control, and salted duck eggs enriched with 2.5% (v/v) LS after 28 days of salting. The TBA value considerably increased with an increase in salting period, and the treated egg's TBA value significantly associated with LS concentration. The TBA value decreased as the LS concentration increased. The amount of LS present was highly associated with their capacity to scavenge DPPH radicals. The reducing power of the samples was substantially correlated with the LS concentration, and the reducing power increased with increasing LS concentration. The GC-MS data revealed that phenols and ketones were the predominant chemicals present in the LS, and they were also found in the eggs added to the LS even though they were absent in the fresh eggs and control. The flavor of the control group and treated eggs with LS differed significantly, according to the principal component analysis and radar map of the E-nose. The texture study results revealed that the LS significantly impacted the hardness, cohesiveness, and chewiness of eggs.

• 분석과학
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• 제30권1호
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• pp.10-19
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• 2017

Anabolic steroids have similar structures to testosterone, both of which promote the growth of muscle mass and increase strength. However, the side effects of anabolic steroid use may lead to heart attacks or strokes. Additionally, the excessive use of steroids inhibits the production of the sex hormones in the body via a negative feedback loop, which results in testicular atrophy in males and amenorrhea in females. Currently, the method of choice used to test for the presence of anabolic steroids is GC-MS. However, GC-MS methods require chemical derivatization of the steroid sample to ensure compatibility with the analytical method; therefore, analysis of many different samples is difficult and time consuming. Unlike GC-MS, the liquid chromatography-quadrupole-time of flight mass spectrometry (LC-Q-TOF-MS) method is suitable for many samples. Twenty-two different anabolic steroids were analyzed by LC-Q-TOF-MS with various collision energies (CE). Accurate mass spectral data were obtained using a Q-TOF-MS equipped with an electro-spray ionization source and operated in the positive MS/MS mode for several classes of steroids that are often the targets of testing. Based on the collected data, fragmentation pathways were carefully elucidated. The high selectivity and sensitivity of the LC-Q-TOF-MS instrument combined with these fragmentation pathways offers a new approach for the rapid and accurate screening of anabolic steroids. The obtained data from the 22 different anabolic steroids will be shared with the scientific community in order to establish a library to aid in the screening of illegal anabolic steroids.

• 한국축산식품학회지
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• 제34권5호
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• pp.700-708
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• 2014

The volatile composition of veal has yet to be reported and is one of the important factors determining meat character and quality. To identify the most important aroma compounds in veal from Holstein bull calves fed one of three diets, samples were subjected to solid-phase microextraction (SPME) combined with gas chromatography-quadrupole mass spectrometry (GC-MS). Most of the important odorants were aldehydes and alcohols. For group A (veal calves fed entirely on milk for 90 d before slaughter), the most abundant compound class was the aldehydes (52.231%), while that was alcohols (26.260%) in group C (veal calves fed starter diet for at least 60 d before slaughter). In both classes the absolute percentages of the volatile compounds in veal were different indicating that the veal diet significantly (p<0.05) affected headspace volatile composition in veal as determined by principal component analysis (PCA). Twenty three volatile compounds showed significance by using a partial least-squared discriminate analysis (PLS-DA) (VIP>1). The establishment of the global volatile signature of veal may be a useful tool to define the beef diet that improves the organoleptic characteristics of the meat and consequently impacts both its taste and economic value.

• Journal of Pharmaceutical Investigation
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• 제41권1호
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• pp.37-43
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• 2011

Urinary steroid levels were investigated in the treatment of CKD-501, a new anti-diabetic drug candidate. CKD-501 was administered orally at the dosage of 1, 2, 4 mg/day for 7 days to normal men (n=18). Urine was collected before, during and after stopping the drug administration and the urinary level of androgen, estrogen, progestin and corticoids were quantified using GC-MS (gas chromatography-mass spectrometry). Only urinary corticosteroid and an androgen, DHEA levels among all the analyzed steroids, have been found to increase progressively, reaching significant levels on the last day of drug treatment and later declined after the drug treatment is withdrawn. Therefore, it was thought that an increase in the urinary corticoid and DHEA levels could be a characteristic of CKD-501, since it prominently acts on the glucose sensitivity and suppresses the triglyceride levels. In conclusion, it was found that CKD-501, an anti-diabetic drug candidate, affects the glucocorticoid and DHEA levels and it plays a crucial role in glucose homeostasis.

• 분석과학
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• 제13권3호
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• pp.277-281
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• 2000

16종의 휘발성 유기화합물을 blank water에 첨가하고 고정상으로 $100{\mu}m$ polydimethyl siloxane을 입힌 solid phase microextraction(SPME) fiber를 사용하는 headspace SPME방법으로 추출하여 gas chromatography/mass spectrometry (GC/MS)로 분석하였다. 이 방법의 평균회수율은 97%, 평균상대표준편차는 4.7%, 그리고 검출한계는 $0.01-0.5{\mu}g/l$를 나타냈다. 즉 SPME 방법을 이용한 수용액 중의 휘발성 유기화합물의 결과는 현재 많이 사용되고 있는 기존의 다른 방법보다 우수하고 편리한 방법으로 나타났다.