Validation of a novel IR measurement method for hydrocarbon contaminations in water and soil by 2D-gas chromatography

01.12.2008 - 31.08.2012
Research funding project
Hydrocarbons are frequent and, due to their toxic and even carcinogenic potential, also very important contaminants of water and soil samples. Their analytical determination is thus of highest relevance. The various standards that exist currently for different fields of applications do, however, provide a strongly non-uniform and unsatisfactory situation, where results that are produced strongly depend on the analytical method chosen. Depending on the actual method chosen, it is possible in the case of gas chromatographic methods not only to obtain a quantitative estimate of the hydrocarbon concentration, but moreover some information on the type of hydrocarbon contamination, based on the chromatographic pattern. The content of hydrocarbons in soil and water samples is typically determined as sum parameter. This means, however, that the result will depend on the actual (standard) method selected for the determination. The determination of hydrocarbon (HC) contaminations in water samples is performed in Europe mainly according to the standard DIN EN ISO 9377-2 which foresees an extraction with an alkane of low boiling point and determination by GC of the compounds eluting in the retention time window of C10-C40. For soil samples, the standard DIN ISO 16703 is applied in which the same type of gas chromatographic determination is preceded by an extraction with an acetone/alkane mixture. Aim of this part of the project is the implementation of the currently applicable standard methods for the setting-up of a highly precise reference analysis for the oil-in-water monitor developed by the company QuataRed for the validation of their apparatus. Furthermore, the GC method is to be scrutinized and optimized with regard to the critical parameters. The influence of the clean-up step, as well as the evaluation of the error inherent to the method when following the protocol prescribed by the standard method for samples of very different volatility is to be mentioned here. The optimisation of the gas chromatographic parameters provides the possibility of significantly reducing this method-specific error. In the second phase of the project the setting up of a two-dimensional GC system (2D-GC) is foreseen. Such a system allows a significantly refined analysis of HC samples, since the separation power (efficiency) of this system is by far superior to that of a one-dimensional GC system. This will allow recognising substance classes already on the basis of the patterns that they produce in the 2D-separation space. Even with the non-selective flame ionisation detector (who is preferred for this task due to its higher data acquisition rate when compared to MS detection), the assignment (identification) of compound classes or in the best case even individual substances will become possible on the base of the characteristic 2D elution pattern. With the help of this 2D-GC system, it shall be tested in the course of the method validation whether the individual steps of the procedure lead to a discrimination of the sample components, that is, whether the application of the standard procedure leads to a bias that is different for the different substance classes. This would result in the large difference of results for samples of nominally the same concentration, however, of different oil type or origin, as is actually observed. It is the aim to establish a compound-class based calibration for the oil-in-water determination which will help to eliminate or at least significantly reduce the method-specific bias that the current standard method actually has.

People

Project leader

Project personnel

Institute

Grant funds

  • FFG - Österr. Forschungsförderungs- gesellschaft mbH (National) Group Basic programs Austrian Research Promotion Agency (FFG) Specific program Bridge

Research focus

  • Environmental Monitoring and Climate Adaptation: 100%

Keywords

GermanEnglish
Kohlenwasserstoff-AnalytikHydrocarbon analysis
Öl in Wasser-Analytikoil in water-analysis
2D-Gaschromatographie2D gas chromatography
IR-MesstechnikIR measurement technology
Umweltanalytikenvironmental analysis

External partner

  • QuantaRed Technologies Gmbh

Publications