Simultaneous Extraction and Determination of Volatile Organic Compounds and Semi-volatile Organic Compounds in Indoor Air Using Multi-bed Solid Phase Extraction Device.

A method for the simultaneous extraction and determination of indoor volatile compounds, including volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs), was developed using a multi-bed solid phase extraction (SPE)-type collection device. The collection device was prepared by packing styrene-divinylbenzene polymer particles and activated carbon particles. The collected analytes were completely desorbed by passing 7 mL of acetone, and the solvent was then injected into a gas chromatograph-mass spectrometry without the concentration process. Because the proposed method does not require ultrasonication and a concentration process of eluted solvent, quantitative determination of a relatively volatile compound could be achieved. The total recovery including extraction and elution recoveries for all the investigated analytes were in the range from 91.6 to 109%. The limit of quantification was less than 4.0 ng L-1 for all the investigated analytes, and relative standard deviations of the peak area of the analytes in indoor air were less than 12%. The collection device could be reused for over 50 samplings.

Quantitative Determination of 2-Ethyl-1-hexanol, Texanol and TXIB in In-door Air Using a Solid-Phase Extraction-type Collection Device Followed by Gas Chromatography-Mass Spectrometry.

In this study, in-door air semi-volatile organic compounds (SVOCs) including 2-ethyl-1-hexanol, 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate (texanol), and 2,2,4-trimethyl-1,3-pentanediol diisobutyrate (TXIB), which are scheduled for adding as regulated compounds concerning indoor air reference values in Japan, were quantitatively extracted using a solid-phase extraction-type collection device, followed by sensitively determined by gas chromatography-mass spectrometry. The developed method has shown a good extraction recovery up to an air sampling volume of 900 L. The extracted analytes were quantitatively and rapidly eluted by 7 mL of acetone. The limit of quantification of the analytes were 0.7, 2.1 and 0.2 ng L-1 in air sample at a sampling volume of 300 mL without any concentration of a desorption solvent. The developed method was applied to simultaneous determinations of the investigated target analytes and phthalate esters in real indoor air samples.

Application and Validation of a Determination Method Using Post-column Reaction Gas Chromatography of Nitrogen-containing Organic Compounds.

In this work, we applied post-column reaction gas chromatography (GC) using a flame ionization detector (FID) system to study nitrogen-containing organic compounds (NOCs). The results were subsequently validated. After separation by column, the target components were converted to carbon dioxide using an oxidizing catalyst and then reduced to methane, followed by detection using an FID. SI-traceable testing mixtures containing NOCs (isoprocarb, napropamide, and pendimethalin) were prepared by the gravimetric blending method. These mixtures were analyzed using a post-column reaction GC-FID system; standard materials of hydrocarbons were used as calibrants in this analysis. The determined values were compared with the values obtained for samples prepared at the corresponding concentrations, and statistical analyses were performed in all cases. It was shown that the determined and prepared values agreed well with each other within the uncertainty limits.

Quantitative Determination of Phthalate Esters from Air Samples Using a Solid-Phase Extraction-type Collection Device.

In this study, a solid-phase extraction-type collection device, with styrene-divinylbenzene polymer particles (Sunpak-H) as the adsorbent, was used for the quantitative determination of phthalate esters in air samples. The collection and elution recoveries of eight volatile phthalate esters, i.e., dimethyl phthalate, diethyl phthalate, dipropyl phthalate, diisobutyl phthalate, dibutyl phthalate, butyl-benzyl phthalate, di(2-ethylhexyl) phthalate, and dioctyl phthalate, were quantitatively evaluated. All analytes were collected using the device up to a sampling volume of 10000 L at a sampling temperature of 35°C without breakthrough. During air collection, moisture was not trapped on the adsorbent. The collected analytes were completely eluted from the device by passing 3 mL of acetone. The eluted solvent was injected into a gas chromatography-mass spectrometry system after the eluted solvent was concentrated, if necessary. After washing the adsorbent using acetone, the device could be reused more than 50 times. The limit of quantification for the analytes was less than 1 ng L-1 in air at a sampling volume of 600 L with solvent concentration. This device was successfully applied for the quantitative determination of phthalate esters in real air samples, including indoor and in-car air.

A Newly Designed Solid-Phase Extraction-type Collection Device for Precise Determination of Polycyclic Aromatic Hydrocarbons in Air.

A newly designed styrene-divinylbenzene copolymer adsorbent packed solid-phase extraction (SPE)-type collection device for the quantitative determination of airborne polycyclic aromatic hydrocarbons (PAHs) containing two to five rings is reported in this manuscript. This SPE-type collection device offers rapid, easy and quantitative elution of the analytes and easier reuse. A small collection device was initially developed for investigating the basic collection and elution performances of the adsorbent with respect to PAHs. The analytes were quantitatively collected on the adsorbent up to 3 m3 of air sampling at a sampling temperature of 35°C. The collected analytes were then completely eluted from the adsorbent by passing 3 mL of dichloromethane without carry-over of the analyte. During air collection, because no moisture was trapped on the adsorbent, the subsequent gas chromatography-mass spectrometric analysis was not influenced by moisture. Based on these successful performances, a wide-bore collection device was introduced for collecting larger air samples. After a quantitative investigation of the collection and elution performances of the wide-bore collection device, it device was successfully applied for precise determinations of PAHs in atmospheric air. Further application and employment of the device for the precise determination of semi-volatile organic compounds in environmental air samples is expected due to these excellent results.

Polydimethylsiloxane-coated partitioning sample collection device for the precise quantification of polycyclic aromatic hydrocarbons in air.

A novel partitioning collection device comprising a glass cartridge packed with poly(dimethylsiloxane)-coated macroporous silica particles was developed for the precise quantification of polycyclic aromatic hydrocarbons in air. The analyte collection and elution performances achieved using different amounts of poly(dimethylsiloxane) coating were quantitatively evaluated. The sample retention power increased with increasing the coating, and more than 250 L of air could be collected without analyte breakthrough at a sampling temperature of 35°C. During the air collection, the moisture in the air was not retained on the particles due to the hydrophobic surface of the sorbent. A complete and rapid elution of the collected analytes from the device was accomplished by the passage of only 10 mL of acetone with ultrasonication for 1 min. The proposed method was successfully applied for the determination of airborne polycyclic aromatic hydrocarbons in tunnel air.