• Archives of Pharmacal Research
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• 제18권2호
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• pp.69-74
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• 1995

In order to improve physico-chemical properties and to enhance stability of drugs, amino acid salt has been widely adoptd in pharmaceutical synthesis. Acetylsalicylic acid lysinate is one of the widely used analgesics and it is a good example of t5his synthesis. In the case of bacetylsalicylic acid lysinate synthesis, racemization of natrually occurred lysine is esential because the racemic lysine salt of the drug shows better yield, crystallinity and dryness than that of the L-lysine salt. To esatablish a simple, practical and economical process for L-lysine racemization, L-lysine treatments with phosphoric acid and with acetic acid were compared and the optimum conditions for its process and derivatization were investigated by chiral separation methods using GC_MS spectroscopy.

• Bulletin of the Korean Chemical Society
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• 제34권10호
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• pp.2921-2924
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• 2013

Immunoliposomes (antibody-conjugated liposomes) are highly useful as both a drug carrier in drug delivery and as a reporting probe in immunodiagnostics. However, antibody conjugation is lengthy and cumbersome, because this includes several steps such as derivatization of the antibody, conjugation of the derivatized antibody to liposomes, and separation of the unbound antibodies from immunoliposomes. Recently, liposome preparation steps have simplified by using microfluidic devices (${\mu}FDs$) where liposomes are formed when a stream of lipids in solvent is hydrodynamically focused between two oblique buffer streams in a microchannel. Herein, we report a simple method for the production of immunoliposomes (rabbit IgG-conjugated liposomes) using microvalve-controlled ${\mu}FD$. The presence of antibody on the liposome was verified by observing the binding of immunoliposomes to rabbit IgG on the surface. The results suggest that immunoliposomes can be easily prepared through sequential mixing of antibody, conjugation reagents, preformed liposomes using microvalve-controlled ${\mu}FD$.

• Bulletin of the Korean Chemical Society
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• 제34권4호
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• pp.1101-1107
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• 2013

In this study, total mercury and methyl mercury in whole blood of Korean was analyzed so as to investigate the correlation between total mercury (T-Hg) and methyl mercury (Me-Hg). 4000 whole blood samples were divided in four groups, according to T-Hg concentration in percentile: group I (p25-p50), group II (p50-p75), group III (p75-p95) and group IV (p95-p100). 100 samples were randomly selected from the each group, and Me-Hg concentration was measured. T-Hg concentration in whole blood was analyzed using a Direct Mercury Analyzer-80 and obtained limit of detection (LOD) was $0.2{\mu}gL^{-1}$. Me-Hg concentration was analyzed with ethylate derivatization using headspace-gas chromatography-mass spectrometry, and obtained LOD of methyl mercury was $0.5{\mu}gL^{-1}$. The geometric means of T-Hg and Me-Hg were $6.35{\mu}gL^{-1}$ and $4.44{\mu}gL^{-1}$, respectively, and 71.91% of T-Hg was presented as Me-Hg.

• Bulletin of the Korean Chemical Society
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• 제25권6호
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• pp.900-906
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• 2004

An RPLC-postcolumn detection method has been developed for the fluorimetric determination of dichloroacetamide (DCAD) in water. After ammonia and DCAD were separated on a $C_{18}$ nonpolar stationary phase with 2.5% methanol-0.02 M phosphate buffer at pH 3, the column eluant was reacted with post column reagents, o-phthaldialdehyde (OPA) and sulfite ion at pH 11.5, to produce a highly fluorescent isoindole fluorophore, which was measured with a fluorescence detector ( ${\lambda}_{ex}$ = 363 nm, ${\lambda}_{em}$ = 425 nm). With the optimized conditions for RPLC and the postcolumn derivatization, the calibration curve was found to be linear in the concentration ranges of 0.5 and 20 ${\mu}$M for DCAD, and the detection limit for DCAD was 0.18 ${\mu}$M (23${\mu}$g/L). This corresponded to 18 pmol per 100 ${\mu}$L injection volume for a signal-to-noise ratio of 3, and the repeatability and reproducibility of this method were 1.0% and 2.5% for five replicate analyzes of 2 ${\mu}$M DCAD, respectively. The degradation yields DCAD to ammonia were 94 and 99%, and the percent recoveries of DCAD from 4 and 6 ${\mu}$M DCAD-spiked tap water were shown mean more than 97%.

• 한국안전학회지
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• 제23권6호
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• pp.62-69
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• 2008

As the concerns of dermal exposure of spray painters to isocyanates in the automobile industry, glove performance was examined like permeation rate and breakthrough time including fatigue test. Methylene chloride was used as the solvent for derivatization of the isocyanates with a 97.5% recovery. Ghost wipe pads were used to wipe the surface of the glove material after chemical penetration through the glove material placed under a disposable test cell. Several solvents were tested, such as thinner(xylene, toluene) and cleaning agent(acetone) by using a standard permeation test cell(AS/NZS standard 2161. part 10.3). Solvents accelerate chemical permeation through the gloves more quickly than pure HDI hardener products. The longest breakthrough times were from Nitrosolve gloves, not detected in 8 hours, compared with others like Latex, Neoprene, TNT and Dermo Plus. Therefore Nitrosolve gloves could be recommended as personal protective equipment in crash repair shops. In addition, revised exposure limit of korean regulation should be suggested for employee to minimize the risk of health symptoms.

• Bulletin of the Korean Chemical Society
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• 제21권11호
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• pp.1119-1124
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• 2000

$\beta-Cyclodextrin$ derivatives connected with diaza-18-crown-6 through flexible bridges (R) at the secondary face 1a-c (1a: R = $-(CH_2)4-;$ 1b: R = $-CH_2CH_2OCH_2CH2-;$ 1c: R = $-(CH_2)8-)$ have been prepared. The associa tion constants of 1 with (2-naphthoxy)alkylammonium ions (2a: alkyl = butyl; 2b: alkyl = octyl) were determined by induced circular dichroism (ICD) spectroscopy and it was found that the derivatization of $\beta-CD$ with the diazacrown resulted in enhanced binding with 2, compared to the native $\beta-CD.$ ICD Characteristics of the host-guest complexes indicate that a part of the alkylammonium moiety of 2 is protruded from the secondary side of the $\beta-CD$ cavity, and the guest molecules 2a and 2b move to the secondary and primary side, respectively, to make the binding of the ammonium group with the diaza-18-crown-6 moiety more feasible. The energy accompanied by the relocation of the guest molecules inside $\beta-CD$ moiety is compensated by the interaction energy between the ammonium ion and diazacrown ether.

• Bulletin of the Korean Chemical Society
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• 제22권7호
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• pp.685-688
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• 2001

A gas chromatography/mass spectrometric assay method has been developed for the simultaneous determination of benzidine (BZ), N-acetyl benzidine (ABZ) and N,N-diacetyl benzidine (DABZ) in rat urine. BZ, ABZ and DABZ were extracted from urine at pH 8 with ethyl ether. Conjugated urinary metabolites were extracted at pH 8 after hydrolysis with 1 M HCl for 30 min at 100 $^{\circ}C.$ The dried extract was dissolved in 100 ${\mu}{\ell}$ of ethylacetate and then injected in gas chromatography-mass spectrometric (GC-MS) system without further purification or modification. BZ, ABZ and DABZ have good chromatographic properties and offer very sensitive response for the EI-MS (SIM) without any derivatization. The recoveries for BZ, ABZ and DABZ were about 98.0, 81.8 and 71.4%, respectively, at pH 8.0 and the concentration of 5.0 ng/mL. The coefficients of variation of BZ and ABZ were less than 9.5% from 0.1 to 100 ng/mL and that of DABZ was less than 13% in the same concentration range. The detection limits of the assay were 0.01 ng/mL for both BZ and ABZ, and 0.05 ng/mL for DABZ in urine or plasma 1.0 mL.

• 분석과학
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• 제20권3호
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• pp.198-203
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• 2007

수용액상에 존재하는 3-monochloropropane-1,2-diol (3-MCPD)의 LC-MS를 이용한 분석방법을 개발하였다. 수용액 시료에 수산화나트륨 용액을 첨가하여 강알칼리 상태를 유지시킨 후, 3-MCPD의 유도체화를 위하여 benzoyl chloride $25{\mu}L$을 넣어 직접 반응시켰다. 반응 후 유도체를 pentane으로 추출하여 LC-MS의 selected ion monitoring (SIM) 법으로 정량하였다. 분석결과 검량선은 $1.0-100{\mu}g/mL$ 농도범위에서 $r^2=0.992$의 상관관계 계수를 갖는 좋은 직선성을 나타내었으며, 검출한계는 $0.01{\mu}g/mL$ 이하였다. LC-MS에 의한 분석방법의 회수율은 92.3-98.0%이었다.

• 대한화학회지
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• 제52권3호
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• pp.239-248
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• 2008

활성탄소섬유(ACF; activated carbon fiber)를 흡착제로 사용한 고상추출법(SPE; solid phase extraction)으로 수용액 시료 중에 존재하는 특정화학물질(schedule chemicals)의 분석법을 연구하였다. 본 연구에 사용된 특정화학물질은 화학작용제류의 가수분해 생성물과 유사작용제로 사용되는 알킬포스포네이트류, 티오디글리콜 등 14종이었다. 분석을 위한 추출물의 실릴 유도체화 반응에서 피리딘을 사용하여 특히 3-quinuclidinol의 유도체화 반응 효율을 높일 수 있었다. 물 시료에서 아민류의 추출 회수율을 개선하기 위하여 SPE-ACF 튜브에 시료를 부하하기 전에 5% triethylamine/MeOH(1 mL) 용액으로 SPE-ACF 튜브를 세척한 후에 시료를 SPE-ACF에 부하하는 방법으로 추출 회수율을 증대시킬 수 있었다. 이 연구를 통해서 수용액 시료에서 특정화학물질을 신속히 검출할 수 있는 최적 조건을 선정하였다.

• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2005년도 국제학술대회
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• pp.337-340
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• 2005

Ethylene oxide is a genotoxic carcinogen with widespread uses as industrial chemical intermediate and gaseous sterilant. 2-hydroxyethylated N-terminal valine in Hb is a good biomarker for biological monitoring of ethylene oxide exposure, because of its stability. We studied the determination method of (N-2-hydroxy-ethyl)valine in hemoglobin adduct by using GC/MS. PFPITC and TBMS were used as appropriate derivatives. Ethylene oxide formed Hb adducts as (N-2-hydroxy-ethyl)valine(HEV) in mouse with ethylene oxide inhalation exposure. Standard HEV can be synthesized with 2-amino-ethanol and 2-bromo-3-methylbutyric acid. GC/MS can measured them after derivatization with pentafluorophenylisothiocianate(PFPITC) and N-(tertiary butyl dimethylsiiyl)-N-methyl-trifluoroacetamide(TBDMS-TFA) by using Edman procedure. Concentrations of Hb adduct were proportionally increased with exposure levels. They were 230${\pm}$35(nmol g$^{-1}$ globin) and 410${\pm}$72(nmol $g^{-1}$ globin) at 200ppm and 400ppm ethylene oxide inhalation exposure, respectively.