Stability of workroom air volatile organic compounds on solid adsorbents for thermal desorption gas chromatography

详细信息    查看全文

• 作者：Volden ; Jon ; Thomassen ; Yngvar ; Greibrokk ; Tyge ; Thorud ; Syvert ; Molander ; Paal
• 关键词：Air sampling ; Solid adsorbents ; Thermal desorption ; Volatile organic compounds (VOCs) ; Tenax TA ; Chromosorb 106 ; Carbotrap ; Storage stability ; Blank build-up
• 刊名：Analytica Chimica Acta
• 出版年：2005
• 出版时间：February 14, 2005
• 年：2005
• 卷：530
• 期：2
• 页码：263-271
• 全文大小：145 K

文摘

The storage stability of the occupationally frequently occurring compounds, methylethylketone, methylisobutylketone, benzene, toluene, tetrachloroethylene, n-butylacetate, α-pinene, β-pinene, limonene and n-decane, has been investigated on the adsorbents Tenax TA, Chromosorb 106 and Carbotrap using thermally desorbable tube type samplers, commonly utilized in ambient and workroom atmospheric measurements. Fifty and 500ng of each compound were loaded on the various adsorbents tubes, stored at both ambient (20°C) and refrigerated (4°C) temperatures and analysed by means of thermal gas chromatography with mass spectrometric detection on days 0, 7, 14 and 28 after exposure. A 90 % storage recovery was chosen as acceptance criteria for storage stability, and statistical testing by Student's t-test, analysis of variance and Bonferroni post hoc tests were employed to investigate the effect of the categorical variables storage time, storage temperature and analyte loading on the different adsorbents. Chromosorb 106 showed the overall best behaviour with recoveries of 90 % or better for all analytes during the 28-day test period. Tenax TA and Carbotrap yielded lower recoveries and were more influenced by variations in storage time, storage temperature and analyte loading. Refrigerated temperatures were best avoided for storage on Tenax TA, but may increase the recovery of some compounds on Carbotrap (e.g. n-butylacetate). The blank build-up on the adsorbents was also investigated, and Carbotrap and Tenax TA showed no signs of artefact development over time. Chromosorb 106, however, contained inherently more artefacts that build up over time, which in spite of the excellent storage capability, may limit its use in field studies where long storage times are normal.