PerkinElmer has produced an application note describing a rapid screening method for methyl-tert-butyl ether (MTBE) and the combination of benzene, toluene, ethylbenzene, and xylenes (BTEX) in petroleum contaminated ground water using solid phase microextraction (SPME) followed by on-site analysis with a Torion T-9 portable GC/MS.
Introduction
MTBE and BTEX compounds are routinely monitored in soil and ground water to determine whether petroleum contamination has occurred due to industrial runoff, or waste water effluent, in order to protect local tributaries and surrounding property. For industrial environmental monitoring programs, the ability to quickly analyse samples taken from nearby ground and water sources is key to environmental protection. The ability to analyse samples at the source, without the need for fixed laboratory analysis, can result in significant time and cost savings, and in the case of a spill, can lead to improved response times.
Sampling using the Custodion® SPME syringe, with separation and analysis using the Torion® T-9 portable GC/MS, allows rapid and on-site sample extraction and analysis, and provides actionable results within minutes. Using the portable Torion T-9 GC/MS, informed decisions can be made in critical situations, and can optimize follow-up activities by providing the user with the appropriate information to determine which, and if, samples should be sent to a laboratory for confirmatory analysis. In addition, on-site sample collection, extraction and analysis, using SPME and the Torion T-9 GC/MS, minimizes target analyte losses, compared to traditional techniques that risk analyte loss during complex storage and transport conditions, therefore ensuring the integrity of critical and valuable samples.
Experimental
The Custodion SPME sampling device used in this application consists of a 1 cm length of silica fibre coated with polydimethylsiloxane (PDMS), divinylbenzene (DVB) and carboxen (CAR). The fibre is housed in a durable syringe that can be operated with a single hand, much like a retractable ballpoint pen. The push-button trigger on top of the Custodion syringe allows the SPME fibre to be extended and retracted
into and out of a protective syringe needle.
Conclusion
MTBE and BTEX compounds were rapidly screened in petroleum contaminated ground water using solid phase microextraction (SPME) followed by on-site analysis with a Torion T-9 portable GC/MS. The SPME-GC/MS method was used to effectively extract, concentrate, separate and detect both MTBE and BTEX quickly and reliably on-site for rapid decision making and cost savings.
