• 한국산업보건학회지
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• 제16권3호
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• pp.222-232
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• 2006

Objectives: The objective of this study was to propose the total isocyanate analytical method which involves derivation of 2,4-toluene diisocyanate(2,4-TDI), 2,6-toluene diisocyanate(2,6-TDI), 4,4'-methylenediphenyl diisocyanate(4,4'-MDI) and 1,6-hexamethylene diisocyanate(1,6-HDI) using 2-chlorobenzyl alcohol(2-CBA) or 2,4-dichlorobenzyl alcohol(2,4-DCBA), and analyzing of hydrolysate of the synthesized urethane with the gas chromatography(GC)/flame ionization detector(FID), GC/pulsed discharge ionization detector-electron capture detector(PD-ECD) and GC/mass selective detector(MSD). Methods: Urethanes were synthesized by reacting 2,4-TDI, 2,6-TDI, 4,4'-MDI and 1,6-HDI to 2-CBA or 2,4-DCBA. Urethanes was verified by TLC, HPLC/UVD and GC/MSD. For field application, the most suitable condition that 2-CBA coated in glass fiber filter removed completely and urethanes were not removed was searched. 2-CBA generated from hydrolysis of urethanes according to hydrolysis conditions. Diisocyanates were collected on field air and analyzed. Results: Urethanes which were white and solid phase synthesized by reacting 2,4-TDI, 2,6-TDI, 4,4'-MDI, 1,6-HDI and 2-CBA or 2,4-DCBA. And urethanes were verified by TLC, HPLC/UVD and GC/MSD. The most suitable conditions to remove 2-CBA coated in glass fiber filter were $87^{\circ}C$ and 20 mmHg and urethanes were not removed under same condition. Hydrolysis yields of urethanes were 99 % to 111 %. 2-CBA, the hydrolysate of urethanes was analyzed by GC/FID, GC/PD-ECD and GC/MSD. Conclusions: Simultaneous analysis of 2,4-TDI, 2,6-TDI, 4,4'-MDI and 1,6-HDI deriving with 2-CBA and 2,4-DCBA, along with a total isocyanate analysis, was feasible with GC/FID, GC/PD-ECD and GC/MSD. This result will be a guide of further study on total isocyanate analysis.

• 약학회지
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• 제37권1호
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• pp.54-65
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• 1993

A method for the determination of 16 residual pesticides in crude deugs was examined. Crude drug was extracted with acetonitrile/water solution and the extract was partitioned between hexane/CH$_{2}$Cl$_{2}$ and NaCl saturated water. The organic layer was passed through cleanup column and subjected to the GC/ECD or GC/NPD analysis. Essential oil components in crude drug interfere with the analysis, and sulfuric acid treatment was adapted to overcome this interference.

• 한국식품과학회지
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• 제33권1호
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• pp.153-156
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• 2001

2단계 발효로 제조한 감식초를 static headspace-GC법과 SPME-GC법으로 휘발성 성분을 각각 포집 분석하여 상호간의 특성에 대해 조사하였다. 감식초의 휘발성 성분 포집조건은 $80^{\circ}C$에서 20분간으로 설정하였으며, 감식초 휘발성 성분의 total FID response는 CW/DVB fiber를 이용한 SPME법에서 total peak area $18.18{\times}10^6$로, static headspace-GC법의 total peak area $1.35{\times}10^6$보다 현저하게 높았다. 감식초의 주된 휘발성 성분으로 acetic acid, ethyl acetate, 3-hydroxy-2-butanone, ethanol, phenethyl alcohol 등이 확인되었으며, static headspace-GC법에서는 acid류 3종, aldehyde류 3종, alcohol류 5종, ester류 8종 및 ketone류 1종이 확인되었다. SPME-GC법에서는 acid류 6종, aldehyde류 7종, alcohol류 6종, ester류 9종, hydrocarbone류 2종, ketone류 1종, 기타 3종으로, 총 34종의 휘발성 성분이 확인되었으며, benzaldehyde, phenethylacetate, phenethylalcohol 등의 비율이 headspace-GC법에 비해 높았다.

• 대한환경공학회지
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• 제36권11호
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• pp.764-770
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• 2014

본 연구는 electron impact-gas chromatography/mass spectrometer (EI-GC/MS)를 이용하여 N-nitrosamines 분석하는 방법의 분리성, 정성 및 정량적 유효성을 평가하였다. 극미량의 검출을 위해 시료전처리는 자동고상추출과 질소농축과정을 거쳐 수행하였다. 표준시료를 전처리 없이 EI-GC/MS (SIM)와 EI-GC/MS/MS (MRM)를 이용하여 직접 분석한 결과, 두 방법 모두 유사한 감응도를 보였다. 반면, 전처리한 표준시료를 EI-GC/MS로 분석한 경우 불순물 피크에 의한 간섭영향에 의해 낮은 ng/L 수준의 정량은 어려운 것으로 나타났다. 8종의 N-nitrosamines에 대한 EI-GC/MS/MS 분석결과, 방법검출한계 및 정량한계는 각각 0.76~2.09 ng/L, 2.41~6.65 ng/L 수준으로 기존 분석방법에 비하여 낮게 나타났다. 첨가농도 10, 20, 100 ng/L에 대한 실험에서 정밀도(1.2~13.6%)와 정확도(80.4~121.8%) 모두 만족하였으며, 검량선의 직선성에 대한 결정계수($R^2$)도 0.999 이상이었다. 환경시료에 대한 대체표준물질(NDPA-$d_{14}$)의 회수율도 86.2~122.3%을 나타내어, 본 연구에서 평가된 방법으로 N-nitrosamines의 정밀분석이 가능함을 검증하였다.

• 한국식품과학회지
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• 제21권6호
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• pp.749-754
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• 1989

탱자(Poncirus trifoliata)의 향기성분을 분석하기 위해 gas co-distillation 방법으로 정유를 추출한 후 GC/retention index(RI)와 GC/MS를 이용해 multi-dimensional analysis를 행하였다. Gas co-distillation 방법으로 탱자의 향도 그대로 지니며 기기분석에 적합한 정유를 얻을 수 있었다. 향기성분의 확인작업에는 GC/RI와 GC/MS를 상보적으로 사용한 multi-dimensional analysis가 효과적이었으며 GC/RI로만 확인할 경우 극성이 다른 두 가지 column을 사용해서 신뢰도를 높일 수 있었다. 탱자에 다량 함유되어 있는 향기성분들은 limonene, myrcene, ${\beta}-caryophllene,\;trans-{\beta}-ocimene,\;{\beta}-pinene$, 3-thujene, 7-geranyloxycoumarin 등으로 밝혀졌으며 확인된 30개의 성분 중 cis-3-hexenyl acetate, n-hexyl acetate, 2-methyl acetophenone, elixene 그리고 elemicine 등은 이제까지 감귤류에서는 발견되지 않았던 새로운 성분들이다.

• 대한화장품학회지
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• 제19권1호
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• pp.1-19
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• 1993

GC/MS는 GC의 분리능과 질량분석기의 화합물의 확인 능력을 결합시킨 기기이다. 질량분석기는 1) 시료를 주입하는 시료 주입부 2) 이온을 형성시키는 ion source 3) 이온을 질량 대 하전비로 분리하는 질량 분석관 4) 분리된 이온을 감지하고 신호를 증폭하는 검출기 5) 검출된 신호로부터 질량스펙트럼을 만들고 데이터를 처리하는 데이터 시스템으로 구성된다. GC/MS는 혼합물을 GC로 분석하여 MS를 반복적으로 주사함으로써 시간에 따른 크로마토그램을 얻은 후 각 성분의 질량스펙트럼으로부터 물질 구조를 확인하는 scan mode와 특정 성분을 높은 감도로서 정량할 수 있는 SIM mode를 수행한다. GC/MS를 이용한 화장품 분석의 예로서 로션, 크림화운데이션, 염모제중의 휘발성분 분석과 비누중의 지방산 분석, 그리고 head space sampler/GC/MS를 이용한 치약 중의 휘발성분 분석 결과를 소개하였다.

• Journal of Gastric Cancer
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• 제22권1호
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• pp.35-46
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• 2022

Background: The correlation between hospital volume and postoperative outcomes has led to the centralization of complex procedures in several countries. However, the results reported in relation to gastric cancer (GC) are contradictory. This study aimed to analyze GC surgical volumes and 30-day postoperative mortality in Italy and to provide a simulation for modeling centralization of GC resections based on district case volumes. Methods: A national registry was used to identify all GC resections, record mortality rates, and track the national in-border GC resection health travel. Hospitals were grouped according to caseload. Centralization of all GC procedures performed within the same district was modeled. The outcome measures were a minimal volume of 25 GC resections/year and the 30-day postoperative mortality. Results: In 2018, 5,873 GC resections were performed in 498 Italian hospitals (mean resections per hospital per year: 11.8); the postoperative mortality rate (5.51%) was tracked from 2016-2018. GC resection health travel ranged from 2% to 50.5%, with a significant (P<0.001) difference between northern and central/southern Italy. The mean mortality rate was 7.7% in hospitals performing one to 3 GC resections per year, compared with 4.7% in those with >17 GC resections/year (P≤0.01). Most Italian districts achieved 25 procedures/year after centralization; however, 66.3% of GC cases in southern Italy vs. 42.2% in central and 52.7% in the northern regions (P<0.001) required reallocation. Conclusion: Postoperative mortality after GC resection correlated with hospital volume. Despite health travel, most Italian districts can reach a high-volume threshold, but discrepancies in mortality rates are alarming.Trial RegistrationResearch Registry Identifierresearchregistry6869

• 분석과학
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• 제20권2호
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• pp.91-108
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• 2007

토양 중 PCBs 분석방법을 검토하기 위해 우리나라 토양오염공정시험방법 및 선진국의 분석방법을 비교 검토하고 결과를 근거로, 추출 및 전처리방법, 칼럼정제방법, 분석용 칼럼 조건, 기기분석 조건 및 정량방법을 검토하였다. 또한 검토된 방법에 따라 토양 중 PCBs 세부분석지침(안)을 제시하고, 제시된 세부분석지침(안)에 의해 PCBs 제품으로 오염시킨 토양 5건 시료와 토지이용도별 및 오염원별 23건의 시료를 전처리하여 분석하였다. 기체크로마토그래피/전자포획검출법(GC/ECD)에 의한 토지이용도별 및 오염원별 PCBs 분석결과는 모든 시료에서 피크패턴(GC/ECD)을 확인 할 수 없었으나, 기체크로마토그래피/질량분석법(GC/MS)에 의한 개별이성체 정량결과는 $0.002{\sim}0.487{\mu}g/kg$ 범위로 검출되었다.

• Journal of Periodontal and Implant Science
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• 제52권6호
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• pp.455-465
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• 2022

Purpose: Periodontal diseases are inflammatory conditions that alter the host's response to microbial pathogens. Type 2 diabetes mellitus (T2DM) is a complex disease that affects the incidence and severity of periodontal diseases. This study investigated the gingival crevicular fluid (GCF) levels of colony-stimulating factor-1 (CSF-1) and interleukin-34 (IL-34) in patients with stage III grade C periodontitis (SIII-GC-P) and stage III grade C periodontitis with uncontrolled type 2 diabetes (SIII-GC-PD). Methods: In total, 72 individuals, including 24 periodontally healthy (PH), 24 SIII-GC-P, and 24 SIII-GC-PD patients, were recruited for this study. Periodontitis patients (stage III) had interdental attachment loss (AL) of 5 mm or more, probing depth (PD) of 6 mm or more, radiographic bone loss advancing to the middle or apical part of the root, and tooth loss (<5) due to periodontal disease. Radiographic bone loss in the teeth was also evaluated; grade C periodontitis was defined as a ratio of the percentage of root bone loss to age greater than 1.0. The plaque index (PI), gingival index (GI), presence of bleeding on probing (BOP), PD, and clinical AL were used for clinical periodontal assessments. GCF samples were obtained and analyzed using an enzyme-linked immunosorbent assay. Results: All clinical parameters-PD, AL, GI, BOP, and PI-were significantly higher in the SIII-GC-PD group than in the PH and SIII-GC-P groups for both the full mouth and each sampling site (P<0.05). The total IL-34 and CSF-1 levels were significantly higher in the SIII-GC-PD group than in the PH and SIII-GC-P groups (P<0.05), and there were significant differences between the periodontitis groups (P<0.05). Conclusions: These findings suggest that IL-34 and CSF-1 expression increases in patients with SIII-GC-PD. CSF-1 was associated with the inflammatory status of periodontal tissues and T2DM, while IL-34 was associated only with T2DM.

• The Korean Journal of Physiology and Pharmacology
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• 제2권4호
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• pp.471-477
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• 1998

Cyclosporin A (CsA), a widely used immunosuppressant, is well known to cause nephrotoxicity and hypertension as major side effects. The present study was aimed at investigating the effects of CsA-pretreatment on the activities of cytosolic guanylate cyclase (cGC) in relation to the alteration of relaxant responses in the rat thoracic aorta. CsA $(10\;{\mu}M)-preincubation$ for 90 min significantly attenuated the vasodilatation induced by sodium nitroprusside (SNP), a cytosolic guanylate cyclase activator, shifting the dose-response curve to the right. The increase in cGMP contents induced by SNP was markedly attenuated by CsA. SNP ($1\;{\mu}M{\sim}\;mM$) increased the cGC activity dose-dependently, and the increase was completely abolished by CsA. CsA attenuated the SNP-induced cGC activation dose-dependently. The abolishing effect of CsA-pretreatment on the SNP-induced cGC activation was not affected by washing the preparation, suggesting that the inhibition is irreversible. When CsA was added simultaneously with SNP, cGC activation was not attenuated. 1-(5-isoquinolinylsulfonyl)-2-methyl piperazine (H-7), a protein kinase C (PKC) inhibitor, decreased SNP-induced cGC activation and blocked the CsA-attenuation of cGC activation. These results suggest that CsA directly inhibits cGC participating in the CsA-induced impairment of vasodilatation, and that PKC is involved in the inhibitory action of CsA on cGC.