Protocol for the Analysis of High Concentrations of Benzene, Toluene, Ethylbenzene, and Xylene Isomers in Water Using Automated Solid-Phase Microextraction−GC−FID

Abstract

Analysis of benzene, toluene, ethylbenzene, and xylene isomers (BTEX) in water using automated solid-phase microextraction (SPME) has been shown to be fast and efficient. However, environmental samples containing free-phase or high concentrations of BTEX must be diluted before analysis can proceed. A protocol based on two dilutions, the first dilution using acetone and the second with distilled water, is described. Separatory funnel experiments indicated the aqueous solubilities of BTEX compounds in a complex mixture can be estimated using Raoult's law. The linear relationship of concentration as a function of response with SPME was more accurate for equal weight BTEX mixtures with concentrations ≤10 mg/L than for concentrations up to 200 mg/L. It is recommended to dilute high-concentration BTEX samples below the aqueous solubility indicated by Raoult's law to ensure accurate quantification. Using this dilution protocol, remediation projects with samples containing free-phase or high concentrations of BTEX can routinely use the SPME−GC−FID analysis method.

Comparison of SPME headspace analysis to U.S. EPA method 5030/8260B for MTBE monitoring

“…Samples were collected in 40‐mL VOA vials using standard water sampling techniques for volatile organic compounds (Koterba et al 1995). Effluent water samples were collected from a 1.5‐L fluidized‐bed bioreactor (Stringfellow and Oh 2002). The bioreactor contained granular activated carbon as a bed material and was used to treat tap water spiked with 10 mg/L MTBE (final concentration).…”

VOC amounts in ambient areas of a high-technology science park in Taiwan: their reciprocal correlations and impact on inhabitants

“…We believe purge and trap (PT) and solid-phase microextraction (SPME) to be the two most efficient technologies. PT and SPME-coupled GC or GC-MS have advanced the analysis of a variety of VOCs, having been widely used to measure the amount of VOCs in water (Aeppli et al 2008;LaraGonzalo et al 2008;Coelho et al 2008;Ruiz-Bevia et al 2009;Thomas et al 1996;Kotowska et al 2006). …”

Preparation and characteristics of sol–gel-coated calix[4]arene fiber for solid-phase microextraction

“…Preparation of the sol-gel SPME fiber involves the following steps: (1) pretreatment of the fused-silica fiber; (2) preparation of the sol solution; (3) sol-gel coating of SPME fiber; and (4) thermal conditioning of the SPME fiber. Prior to sol-gel coating, the protective polyimide layer of a 6 cm-long fused-silica fiber including a 1 cm end segment was removed by dipping it in acetone for 3 h. Then the fiber was dipped in 1 M NaOH solution for 2 h, to expose the maximum number of silanol groups on the surface of the fiber, and cleaned with water.…”

“…Up to now, it has been used to determine benzene derivatives [2,3], chlorinated hydrocarbons [4], herbicides [5,6], polycyclic aromatic hydrocarbons (PAHs) [7][8][9], phenols [10], aromatic amines [11,12], polychlorinated biphenyls (PCBs) [13], organometals [14][15][16][17][18] and so on. SPME is based on the partitioning of analytes between the sample and the extraction phase, which is fixed on the surface of a fused-silica fiber.…”