Multi-Adsorbent Preconcentrator with Waveguide Capillary Detector for Real-Time VOCs Analysis

• Main Authors: Yu-Chen Shen, 沈宥榛
• Other Authors: Hung-Wei Chang
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/37641558811589455169

碩士 === 輔仁大學 === 化學系 === 104 === The development and testing of a multi-stage preconcentrator with waveguide capillary GC detector analytical system for wide volatility range of volatile organic compounds (VOCs) mixture is described. 1-dodecanethiol monolayer protected gold nanoparticles (C12-AuNPs) were immobilized on the waveguide capillary and designed to determine the VOCs thermally desorbed from preconcentrator and separated by a 15-m capillary GC column. The VOCs eluents caused the shift of C12-AuNPs localized surface plasmon resonance band. The preconcentrator is constructed by a stainless steel capillary (ID: 1-mm) packed with 2-mg of Carbopack B, 6-mg of Carbopack X, and 1.8-mg of Carboxen 1000 gives sufficient capillary for 1-L air sample capacity containing four indicating VOCs: acetone, benzene, toluene and m-xylene at concentrations of 500 ppb as well as providing half-height peak width < 4s for m-xylene at a desorption temperature of 280 oC and a flow rate of 2.4 mL/min. After sampling, the preconcentrator was purge with dry nitrogen to remove the moisture and to reduce the water interference to waveguide capillary detector. This multi-stage preconcentrator showed good reliability after the purge nitrogen with multi-stage preconcentrator. In our preliminary challenging VOCs, the detection limits varies from 3.03 g (acetone) to 0.009 g (limonene) depending on the target VOCs volatility and affinity to dodecanethiol ligand covering the gold nanoparticle. This system can used to analyze wide range volatility VOCs (vapor pressure from 3 to 184 mmHg) in 30 minutes and show good potential for compact GC system.