• 한국식품영양과학회지
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• 제41권12호
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• pp.1753-1757
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• 2012

LC-MS/MS를 사용함으로써 인체 혈장에서 ginsenoside Rb1의 분석법을 개발하고 검증하였다. 유속 0.9 mL/min에 이동상 0.1% formic acid가 첨가된 water와 methanol을 사용하여 기울기 용리 조건으로 설정하였으며 사용한 분석 칼럼은 C 18($4.6mm{\times}150mm$, particle size 5 ${\mu}m$)을 사용하여 분리하였다. MRM(multiple reaction monitoring) 방법의 전기 분무 이온화 이온 분석기로 모니터링 하여 분석하였다. 인체 혈장 샘플은 액체-액체 추출방법에 의해 acetone과 water가 섞인 용액으로 추출하였다. 이 분석의 검량선 범위는 10~500 ng/mL이며 상관계수는 0.9995를 나타냈다. 일내, 일간의 정밀성 농도범위는 상관계수 5.8% 그리고 정확성은 96.0~104.6%로 나타났다. 이 LC-MS/MS를 이용한 인체 혈장의 ginsenoside Rb1의 연구가 약동학 연구에 적용할 수 있을 거라 생각한다.

• Asian-Australasian Journal of Animal Sciences
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• 제32권3호
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• pp.375-386
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• 2019

Objective: We hypothesized that silage additives may alter the undigested neutral detergent fiber (uNDF) content through ensiling. Therefore, urea and formic acid were applied to corn, whole barley crop (WBC) and alfalfa to change uNDF content of the ensiled forages. Methods: Six experimental diets at two groups of high uNDF (untreated corn and alfalfa silages [CSAS] and untreated whole barley and alfalfa silages [BSAS]) and low uNDF (urea-treated corn silage+untreated alfalfa silage [$CS_UAS$], urea-treated whole barley silage+untreated alfalfa silage [$BS_UAS$], untreated corn silage+formic acid-treated alfalfa silage [$CSAS_F$], and untreated whole barley silage+formic acid-treated alfalfa silage [$BSAS_F$]), were allocated to thirty-six multiparous lactating Holstein dairy cows. Results: The untreated silages were higher in uNDF than additive treated silages, but the uNDF concentrations among silages were variable (corn silage0.05). Milk yield tended to increase in the cows fed high uNDF diets than those fed low uNDF (p = 0.10). The cows fed diet based on urea-treated corn silage had higher milk yield than those fed other silages (p = 0.05). The substitution of corn silage with the WBC silage tended to decrease milk production (p = 0.07). Changing the physical source of NDF supply and the uNDF content from the corn silage to the WBC silage caused a significant increase in ruminal $NH_3-N$ concentration, milk urea-N and fat yield (p<0.05). The cows fed diets based on WBC silage experienced greater rumination time than the cows fed corn silage (p<0.05). Conclusion: Administering additives to silages to reduce uNDF may improve the performance of Holstein dairy cows.

• Bulletin of the Korean Chemical Society
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• 제33권1호
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• pp.177-182
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• 2012

A new composition of standardized Scutellariae Radix extract (HPO12) was developed for treatment of Alzheimer's disease. For the preclinical pharmacokinetic study of HPO12, a rapid, sensitive, and selective LCMS/MS method was developed and validated for the simultaneous determination of 4 bioactive compounds, baicalein, baicalin, wogonin, and wogonoside. After extraction with ethylacetate, chromatographic analysis was performed on a Thermo $C_{18}$ column ($150mm{\times}2.1mm$, $3{\mu}m$) with a mobile phase consisting of 0.1% formic acid (A) and 0.1% formic acid in 95% acetonitrile (B) by using gradient elution at a flow rate of $250{\mu}L/min$. Analytes introduced to a mass spectrometer were monitored by multiple reaction monitoring (MRM) in positive ion mode. Using $25{\mu}L$ of plasma sample, the method was validated over the following concentration ranges: 25-5000 ng/mL for baicalein, 20-40000 ng/mL for baicalin, 1-1000 ng/mL for wogonin, and 5-10000 ng/mL for wogonoside. The intra- and inter-day precision and accuracy of the quality control samples at the 4 concentrations showed $\leq$ 13.7% relative standard deviation (RSD) and 86.6-105.5% accuracy. The method was successfully applied to determine the concentrations of baicalein, baicalin, wogonin, and wogonoside in rat plasma after intraperitoneal and oral administrations of HPO12.

• Archives of Pharmacal Research
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• 제28권4호
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• pp.463-468
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• 2005

The purpose of the present study was to develop a standard protocol for imidapril hydrochloride bioequivalence testing. For this reason, a specific LC-MS method was developed and validated for the determination of imidapril in human plasma. A solid-phase extraction cartridge, $Sep-pak^{R}$ C18, was used to extract imidapril and ramipril (an internal standard) from deproteinized plasma. The compounds were separated using a XTerra $MS^{R}$?C18 column ($3.5 {\mu}m, 2.1\times150 mm$) and $acetonitrile-0.1\%$ formic acid (67:33, v/v) adjusted to pH 2.4 by 2 mmol/L ammonium formic acid, as mobile phase at 0.3 mL/min. Imidapril was detected as m/z 406 at a retention time of ca. 2.3 min, and ramipril as m/z 417 at ca. 3.6 min. The described method showed acceptable specificity, linearity from 0.5 to 100 ng/mL, precision (expressed as a relative standard deviation of less than $15\%$), accuracy, and stability. The plasma concentration-versus-time curves of eight healthy male volunteers administered a single dose of imidapril (10 mg), gave an $AUC_{12hr}$ of imidapril of $121.48\pm35.81 ng mL^{-1} h$, and $C_{max} and T_{max}$ values of $32.59\pm9.76 ng/mL and 1.75\pm0.27 h$. The developed method should be useful for the determination of imidapril in plasma with sufficient sensitivity and specificity in bioequivalence study.

• Mass Spectrometry Letters
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• 제10권2호
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• pp.43-49
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• 2019

The aim of this study was conducted to develop an analytical method to determine the concentration of ceftiofur residue in eel, flatfish, and shrimp. For derivatization and extraction, the sample was hydrolyzed with dithioerythritol to produce desfuroylceftiofur, which was then derivatized by iodoacetamide to obtain desfuroylceftiofur acetamide. For purification, the process of solid phase extraction (Oasis HLB) was used. The target analytes were confirmed and quantified in $C_{18}$ column using liquid chromatography-tandem mass spectrometry with 0.1% formic acid in water (A) and 0.1% formic acid in acetonitrile (B) as the mobile phase. The linearity of the standard calibration curve was confirmed by a correlation coefficient, $r^2>0.99$. The limit of quantification for ceftiofur was 0.002 mg/kg; the accuracy (expressed as the average recoveries) was 80.6-105%; the precision (expressed as the coefficient of variation) was below 6.3% at 0.015, 0.03, and 0.06 mg/kg. The validated method demonstrated high accuracy and acceptable sensitivity to meet the Codex guideline requirements. The developed method was tested using market samples. As a results, ceftiofur was detected in one sample. Therefore, it can be applied to the analysis of ceftiofur residues in fishery products.

• 한국식품영양과학회지
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• 제44권10호
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• pp.1594-1598
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• 2015

본 연구에서는 추출용매에 첨가하는 산의 종류 및 농도를 달리하여 검정콩으로부터 안토시아닌 및 프로안토시아니딘 색소의 추출효율에 대하여 연구하였다. 산의 종류는 hydrogen chloride(HCl), acetic acid, formic acid, phosphoric acid 및 citric acid였으며, 사용된 농도는 0.1, 0.2, 0.3, 0.5 및 0.7%였고 80% 메탄올을 추출용매로 사용하였다. 총 안토시아닌 함량은 산의 종류 및 농도에 따라 0.74~1.74 mg/g 범위였으며 0.3% HCl 처리구가 가장 높았다. 검정콩의 주요 안토시아닌은 C3G, D3G 및 Pt3G였으며 구성 안토시아닌 중 C3G의 비율이 가장 높았다. 프로안토시아니딘 함량은 2.01~5.29 mg/g 범위로 포도씨나 팥의 프로안토시아닌보다 더 많은 양이 함유되어 있었다. 본 연구 결과로부터 검정콩의 안토시아닌과 프로안토시아니딘의 추출시 산의 종류 및 농도가 중요한 변수이며, 최적 추출조건은 0.3% HCl을 포함하는 80% 메탄올이라 판단된다.

• 멤브레인
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• 제1권1호
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• pp.44-54
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• 1991

가교제의 양과 희석용매의 종류(톨루엔, 시클로헥산, 시클로-핵산올) 및 희석용매의 비에 따라 양이온 교환막인 술폰화 폴리스티렌-디비닐벤젠 공중합체 분리막을 합성한 후 특성화하고, pH와 초기농도의 변화에 따른 유기산 투과량의 변화를 고찰하였다. 제조한 막은 가교제의 양이 감소할수록, 단량체 용액의 희석정도가 클수록 함수율과 이온교환용량은 증가하는 경향을 보였다. 희석용매로는 시클로헥산올을 사용한 막이 다른 용매를 사용한 막에 비해 더욱 다공질이고 큰 함수율과 이온교환용량을 보였다. 유기산의 투과실험에서는 수용액상의 포름산, 아세트산과 같은 카르복시산은 pH가 pKa보다 낮아질수록 투과량이 증가하였으며, 아미노산인 L-알라닌은 등전점 pH에서 투과량의 최소치를 나태내었다. 한편, 모든 유기산에 대하여 초기농도 증가에 따른 플럭스의 변화는 전형적인 포화속도론적 경향을 나타내었다.

• 한국염색가공학회지
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• 제19권3호
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• pp.12-17
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• 2007

In this study, we have investigated properties and behaviors of the indigo vat dyeings on synthetic fibers, namely PET and PTT/Spandex. In addition, indigo vat dyeing conditions such as dyeing temperature, dye concentration and pH were optimized. The finding results show that higher color strengths of indigo dyeings on the two types of applied fibers were obtained at $110^{\circ}C$ and $90^{\circ}C$, respectively. Furthermore, acid leuco dyeings on the fiber substrates using acetic acid and formic acid show higher dye uptake with compared to alkali leuco counterparts.

• Asian-Australasian Journal of Animal Sciences
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• 제32권6호
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• pp.856-864
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• 2019

Objective: The objective of this study was to investigate effects of mixed organic acids (MOA) on nutrient digestibility, volatile fatty acids composition and intestinal microbiota in growing-finishing pigs fed high wheat bran diet. Methods: Six crossbred barrows ($Duroc{\times}Landrace{\times}Yorkshire$), with an average body weight $78.8{\pm}4.21kg$, fitted with T-cannulas at the distal ileum, were allotted to a double $3{\times}3$ Latin square design with 3 periods and 3 diets. Each period consisted of a 5-d adjustment period followed by a 2-d total collection of feces and then a 2-d collection of ileal digesta. The dietary treatments included a corn-soybean-wheat bran basal diet (CTR), mixed organic acid 1 diet (MOA1; CTR+3,000 mg/kg OA1), mixed organic acid 2 diet (MOA2; CTR+2,000 mg/kg OA2). Results: Pigs fed MOA (MOA1 or MOA2) showed improved (p<0.05) apparent total tract digestibility (ATTD) of gross energy, dry matter and organic matter, and pigs fed MOA2 had increased (p<0.05) ATTD of neutral detergent fiber compared to CTR. Dietary MOA supplementation decreased (p<0.05) pH value, and improved (p<0.01) concentrations of lactic acid and total volatile fatty acids (TVFA) in ileum compared to CTR. Pigs fed MOA showed higher (p<0.05) concentration of acetic acid, and lower (p<0.05) content of formic acid in feces compared to CTR. Pigs fed MOA1 had increased (p<0.05) concentration of TVFA and butyric acid in feces. Pigs fed MOA1 showed higher concentration of Lactobacillus and lower concentration of Escherichia in feces compared to CTR. Conclusion: Dietary supplementation of MOA 1 or 2 could improve nutrients digestibility, TVFA concentration and intestinal flora in growing-finishing pigs fed high fiber diet.

• 대한화장품학회지
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• 제11권1호
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• pp.1-12
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• 1985

A strain of Pseudomonas aeruginosa was isolated from the spoiled product and its characteristics on various formaldehyde-releasing preservatives were investigated. This strain, P. aeruginosa FR, could utilize 1.0% of imidazolidinyl urea and 0.2% of DMDM hydantoin as a sole carbon and nitrogen source in the minimal salts medium. With the growth of the strain in minimal salts medium containing imidazolidinyl urea, formic acid was initially accumulated according to the decrease of formaldehyde concentration. It was suggested that formaldehyde dehydrogenase was involved in this oxidation process and could catalyze formaldehyde, imidazolidinyl urea, DMDM hydantoin and quaternium-15, but not bronopol. MICs of this strain to each preservation were 0.03% in formaldehyde, 1.0% in imidazolidinyl urea, 0.2% in DMDM hydantoin, 0.2% in quaternium-15 and 0.1% of EDTA-2Na. But the MICs were diminished about ten times when 0.01% of EDTA-2Na was added to the preservative systems. In actual challenge test, the eyeliner and the pack which contained paraben and imidazolidinyl urea were not able to be protected from this strain, but when 0.05% EDTA-2Na was added the products were sufficiently preserved.