• Archives of Pharmacal Research
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• 제13권3호
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• pp.215-220
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• 1990

Two different, derivative spectrophotometric and gas-liquid chromatographic, procedures for direct quantitation of caffeine and some commonly dispensed antihistaminics in bulk forms, in their laboratory prepared mmixtures and in dosage formulations, have been investigated. The limit, sensitivity reproducibility and accuracy of each method were studied for each individual drug substance and in some usual pharmaceutical formulations.

• 한국임상약학회지
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• 제22권2호
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• pp.167-175
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• 2012

Different studies have been conducted regarding caffeine as psychostimulant drugs and its effects as well as determination in various materials. Since, coffee and tea are most drinkable beverage in the world and their major constituent is caffeine. So, analysis of the effect of equal amount of caffeine in coffee and tea with respect to SD rats was studied. The present methodology was purposed to determine and validate caffeine amount in different brands of coffee and tea, and canvass locomotor and behavioral patterns of SD rats after administrating coffee and tea orally consisting of same amount of caffeine (10, 30 mg/kg). Determination of caffeine in different brands of coffee and tea and validation of caffeine were evaluated using HPLC. Depending upon different brands of tea and coffee, caffeine amount was altered. Meanwhile, amount of caffeine in tea was directly proportional to the temperature of liquid. Coffee and tea (Instant Maxim original coffee$^{(R)}$ and earl grey black tea$^{(R)}$) consisting 10, 30 mg/kg of caffeine were studied in SD rats for locomotor activity and behavioral patterns using Tru Scan 99. The locomotor activities of SD rats were increased after administration of coffee and tea consisting caffeine compared to water. The coffee consisted of higher amount of caffeine exhibited steep movement of SD rats. Similarly, rearing and scratching of SD rats as frequency and duration were increased in coffee and tea consisting caffeine compared with water. The study revealed that coffee and tea had effects in locomotor activity and behavioral patterns of SD rats.

• 분석과학
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• 제26권6호
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• pp.353-356
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• 2013

A method on the determination of caffeine in beverage with acridiene orange-${\beta}$-cyclodextrin (CD) inclusion complex was developed. The conditions such as pH of the sample solution and concentration of acridine orange and ${\beta}$-CD were optimized to 12.0(${\pm}0.5$), $1.9{\times}10^{-6}M$ and $1.25{\times}10^{-3}M$, respectively. Under these optimum conditions, the calibration curve of caffeine was obtained over concentration range of $5{\times}10^{-5}{\sim}1.1{\times}10^{-3}M$. The detection limit was $1.0{\times}10^{-5}M$. The relative errors(%) in beverage samples were less than 5.0%.

• 분석과학
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• 제21권2호
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• pp.84-92
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• 2008

속빈 섬유-액상 미량추출법(hollow fiber-liquid phase microextraction, HF-LPME)과 기체 크로마토그래프/질소-인 검출기(GC-NPD)를 사용하여 사람의 뇨와 여러 가지 음료 중에서 극미량의 카페인을 분석하는 방법을 확립하였다. 수용액 시료로부터 카페인의 양을 측정하기 위해서 속빈 섬유의 길이, 추출용매의 종류, 교반효과, pH 및 염석효과 등 여러 가지 실험적인 파라미터를 변화시켜서 최적의 조건을 확립하고자 하였다. 검정곡선의 회귀계수($r^2$)는 0.9994이상이었으며, 평균 상대 회수율은 102%(n=3)이었으며, 기기검출한계는 2.5 ng/mL, 정량한계는 10 ng/mL이었다. 확립된 HF-LPME 방법은 생물학적 시료, 음식물, 환경시료 중에서 카페인의 농도를 측정하기에 편리하고 정확한 방법이 될 것이다.

• 한국동물학회지
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• 제19권4호
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• pp.161-170
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• 1976

筋小胞體의 Ca能動輸送은 caffeine에 의하여 阻害되므로 筋小胞體 切片에 대한 caffeine의 작용을 조사한 결과는 다음과 같다. caffeine은 근소포체 표면에 結合하지 않거나 결합하여도 그 결합은 극히 약한 결합으로 생각된다. caffeine은 筋小胞體 표면의 遊離 SH基를 증가시킨다. 따라서 caffeine에 의하여 근소포체 단백질의 표면변화가 일어나서 그 결과 Ca에 대한 輸送能이 低下되는 것으로 생각된다.

• 한국식품위생안전성학회지
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• 제5권4호
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• pp.213-217
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• 1990

커피, 홍차, 녹차중의 카페인 함량을 간단하고 신속하게 정량하는 방법을 검토하였다. 역상계 액체크로마토그래피에 의한 카페인 정량은 메타놀-초산-물(20 : 1 : 79)을 이동상으로 하여 ${\mu}-Bondapak$ C18 컬럼하에서 이루어졌다. 카페인의 검출에는 UV검출기를 사용하여 280 mm에서 행하였다. Sep-Pak alumina A 카트리지를 이용한 간단한 전처리를 통해 효과적으로 카페인의 추출 및 clean-up를 행하였다. 카페인의 첨가 회수율은 95.2~101.3%이었고 분석의 재현성은 상대표준 편차로서 0.10~0.62%이었으며 검출한계는 $0.1;\mu\textrm{g}$/ml이었다.

• 한국작물학회지
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• 제53권2호
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• pp.224-232
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• 2008

고 기능성 유용 차나무 품종육성 및 녹차의 이용성 증진 연구의 기초 자료를 제공하기 위해 녹차 함유 catechin 화합물 및 caffeine 성분을 동시에 분석할 수 있고, 재현성 및 검출 감도가 증진된 최적의 HPLC 분석 조건을 검토한 결과를 요약하면 다음과 같다. 1. 녹차에 함유된 catechin 화합물 및 caffeine의 동시분석을 위한 최적 HPLC 분석 조건을 검토한 결과 컬럼은 YMC-pak ODS-AM 303(25 cm)컬럼을 이용하고, 검출파장은 280 nm, 컬럼온도를 $30^{\circ}C$, 분당유속은 1 mL, 이동상 용매로는 A용매로 0.1% 인산 - 증류수, B용매로 100% MeOH를 사용하여 농도구배 조건으로 분석하는 것이 가장 효율적 분석법으로 조사되었다. 2. 녹차에 함유된 catechin 화합물 및 caffeine을 동시에 분석할 수 있는 최적 HPLC분석조건의 재현성 검정을 실시한 결과 머무름 시간(Rt.)의 변이계수는 최대 1.23% 미만, peak area의 변이계수는 최대 5.13% 미만을 나타내어 확립된 녹차 함유 catechin 9종 화합물 및 caffeine의 HPLC 정량분석법은 재현성이 높은 분석법으로 확인되었고, 각 cafechin 화합물 및 caffeine 성분의 최소 검출한계는 최소 50ppb(0.050 ppm, 50 ng/mL)이하로 조사되어, 확립된 HPLC 분석법은 녹차의 작물학적 특성 평가용으로 활용하기에 전혀 무리가 없는 분석법으로 판단되었다.

• 한국지역사회생활과학회지
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• 제24권1호
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• pp.5-12
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• 2013

Caffeine is an alkaloid of the methylxanthine family known as a central nervous system stimulant, temporarily warding off drowsiness and restoring alertness in humans. There is a recommended upper limits of caffeine for health because a high dose can cause negative effects. Chlorogenic acid is a natural polyphenol compound known to have an antioxidant activity. In this study, the contents of caffeine and chlorogenic acid in coffee beans from different origins(Costa Rica, Indonesia, Vietnam) were determined by using liquid chromatography-tandem mass spectrometry(LC-MS/MS). The experiment offers more selectivity and sensitivity for those compounds compared with conventional methods such as UV/VIS spectrophotometry. The average concentrations of caffeine and chlorogenic acid in coffee beans origined in Costa Rica were 15.05 mg/g and 5.33 mg/g respectively. In the case of coffee beans origined in Indonesia, the average concentrations were 13.10 mg/g for caffeine and 3.75 mg/g for chlorogenic acid. Vietnamese coffee showed that the average concentrations were 17.79 mg/g for caffeine and 1.12 mg/g for chlorogenic acid. This study can contribute to a better understanding of the contents of caffeine and chlorogenic acid in various coffee beans in order to evaluate dietary intake.

• 약학회지
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• 제60권3호
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• pp.112-117
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• 2016

A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the determination of caffeine in forensic aqueous sample. The centrifuged sample ($100{\mu}l$) was diluted 50-fold with distilled water. The diluted sample ($400{\mu}l$) was then diluted further with $200{\mu}l$ of 0.1% formic acid solution and $400{\mu}l$ of acetonitrile containing 500 ng of caffeine-(3-methyl-$^{13}C_3$) prior to LC-MS/MS analysis. The mobile phase was composed of 0.1% formic acid in distilled water (A) and acetonitrile (B). Chromatographic separation was performed by using a Zorbax SB-C18 ($100mm{\times}2.1mm$ i.d., $3.5{\mu}m$) column and caffeine was eluted within 1.1 min. Linear least-squares regression with a 1/x weighting factor was used to generate a calibration curve with the coefficients of determination ($r^2=0.9983$). The lower limit of quantification was $25ng/ml$ for the analyte. The process efficiency was 98.6~100.1%. Intra- and inter-day precisions were not more than 2.1% and 1.7%, while intra- and inter-day accuracies were ranged from -6.8 to 4.5%, respectively. The suitability of the method was examined by analyzing unknown forensic aqueous samples.

• 약학회지
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• 제19권4호
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• pp.240-245
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• 1975

The quantitative analysis of ethambutol.2HCl as well as commercial ehambutol preparations was undertaken by gas-liquid chromatography by finding optimum conditions, such as the use of internal standard, stability of an ethambutol-2HCl-caffeine standard solution, and the effect of column temperature, N, O-bis-(trimethylsily) acetamide [B.S.A.] concentrations and other substances present in the preparations. Under the chromatiographic conditions, an ethambutol-2HCl. caffeine standard, 9 min, 30sec. The relative molar response of ethambutol.2HCl and caffeine studied was 2.08. Ethambutol.2HCl could be quantitated up to 1$\times$10$^{-8}$ moles. the possible decomposition of B.S.A. due to the moisture when tested and the incoplete reaction for silylation could be minimized.