Abstract
Simple and compact sampling device is obviously preferable to an indoor air quality monitoring of museum environment for calm appreciation. Authors have developed a novel passive sampler by serially connecting two porous polyethylene tubes containing DNPH coated silica for trapping carbonyl compounds and carbon molecular sieves for volatile organic compounds (VOCs), respectively. The sampler was tested to measure indoor air concentrations of such compounds in an exhibition room of Takehiko Miyanaga Memorial Museum, Hadano, Japan, which displays oil paintings. The sampling performance of the novel sampler for carbonyl compounds was compared with that of a previous sampler, DSD-DNPH, because 16% of diffusion area was reduced by docking two diffusion tubes. Six pairs of both samplers were deployed in the exhibition room at a height of 2 m for 38.5 hrs. After samplings, the DNPH derivatives were eluted by acetonitrile and subsequently determined by HPLC. No significant difference was found in the collected amounts of formaldehyde and acetaldehyde (t-test, p<0.05). Then, sampling rates of DSD-DNPH were used for converting the collection amounts of analytes to air concentrations. Among VOCs, toluene, m,p-xylene and p-dichlorobenzene were significantly determined by GC/MS after extraction in 2ml of carbon disulfide. Sampling rates of a previous passive sampler for VOCs (VOC-SD) were applied to the new sampler. Field measurements were conducted at three sites in the exhibition room and one outdoor for 38.5 hrs from 9 to 11 July 2006. The travel blanks were very low to realize highly sensitive measurements at μg/m3 level. The concentrations of such organic compounds were much lower than indoor air quality guidelines set by Ministry of Labour and Welfare, Japan. Even though indoor/outdoor concentrations ratios formaldehyde, acetaldehyde and m,p-xylene, which showed greater than unity, indicated possible indoor emission sources of these compounds, the indoor air quality of the museum was well controlled by mechanical ventilations.
