| Summary: | 碩士 === 國立臺灣大學 === 環境衛生研究所 === 91 === 1,4-dichlorobenzene and naphthalene are the two major insect repellents in Taiwan.Becausethe conventional sampling method currently used can collect 1,4-dichlorobenzene and naphthalene in gaseous phase,but not in particle phase,the exposure to the chemicals at workplace is generally underestimated.
The purpose of this study was to evaluate a sampling method that can trap 1,4-dichlorobenzene and naphthalene in both gas and solid phases simultaneously.We used a cassette equipped with PTFE filter to connect the charcoal tube instead of charcoal tube only.
1.The coefficient values of calibration curves for standard materials of 1,4-dichlorobenzene and naphthalene were greater than 0.995. The methodology detection limits were 0.85μg/sample for 1,4-dichlorobenzene and 0.50μg/sample for naphthalene.The quantitation detection limits were 27μg/sample for 1,4-dichlorobenzene and 36μg/sample for naphthalene.When the 1,4-dichlorobenzene and naphthalene were spiked together,the charcoal desorption efficiency were 89.7% and 63.6%,respectively.For the stability tests the standard materials of 1,4-dichlorobenzene and naphthalene were spiked together in charcoal and stored at either warm temperature or at 40C in dark,the recovery rates were between 90~100% in 28 days.
2.The method of using PTFE filter had good recovery rates :96.8% for in 1,4-dichlorobenzene and 95.1% for naphthalene because there was no interference that may occur using PVC filter.
3.To examine the adsorption effect of this device by using standard gas generator system,we found that the cassette and the adaptor could adsorp chemicals in the vapor phase.
4. The recovery rate of sampling 1,4-dichlorobenzene in test chamber by using the cassette with a PTFE filter incorporated with the charcoal tube was greater that of using charcoal tube alone.This result indicates that using charcoal tube alone for sampling 1,4-dichlorobenzene generated by stirring operator.However,further verification about the detection limit,the quantitative detection limit and the sample storage stability are needed,if the method will be applied on site.
5. Chromosorb 106 instead of activated charcoal tube is suggested for sampling naphthalene because of the bad desorption efficiency due to charcoal tube.
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