화학공학소재연구정보센터
Korean Chemical Engineering Research, Vol.42, No.1, 65-69, February, 2004
Headspace Sampler와 Gas Chromatography를 이용한 방향족 화합물의 무차원 헨리 상수 측정
Measurement of Dimensionless Henry’s Law Constants of some Aromatic Compounds using a Headspace Sampler with a Gas Chromatography
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초록
방향족화합물의 무차원 헨리상수(Air/Water 분배계수: Kaw)를 headspace sampler(HSS)와 gas chromatography(GC)를 이용하여 318.15-355.15 K온도 범위에서 온도를 변화시키며 측정하였으며, 이 방법으로 시료의 평형 및 채취, 분석 과정에 있어서 용질의 휘발로 인한 오차와 수작업에 의한 측정 오차를 최소한으로 줄이고자 하였다. HSS내 평형용기의 기상과 액상조성은 GC의 피크면적과 물질수지 식으로부터 계산하였으며, 이 관계식을 이용하여 benzene을 비롯한 몇 개의 방향족 화합물의 무차원 헨리상수를 온도별로 측정하였고 문헌값과 비교하여 방법의 신뢰성을 확인하였다. 또한 온도와 무차원 헨리상수의 함수관계를 통해 온도에 따른 무차원 헨리상수 값을 유추하는 방법의 가능성을 살펴보았다.
Dimensionless Henry’s law constants of aromatic compounds in water were measured at various temperatures between 318.15-355.15 K using a headspace autosampler with a gas chromatography. This measuring system prevent, sample losses due to volatilization from equilibration, sampling, and chemical concentration analysis by a high precision headspace sampler and gives relatively accurate results. Dimensionless Henry’s law constant is calculated by thermodynamic relation and the mass balance with gas chromatographic peak area. Different equilibrium concentration in gas phase was made by using different gas-liquid volume ratio in sample vial. The temperature dependence of dimensionless Henry's law constant was correlated with the classical van’t Hoff equation as a function of temperature. The extrapolated data at 298.15 K from correlated equation were compared with available literature data in order to test this method.
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