Achieve exceptional resolution of PAHs, including several isomer sets Using SLB®-ILPAH capillary GC columns

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous in the environment and belong to the persistent organic pollutants (POPs). Monitoring is important because several of them are identified as carcinogens.  Multiple isobaric isomers of PAHs exist, which are difficult to resolve chromatographically on conventional columns. The SLB®-ILPAH is a special purpose column for based on an ionic liquid stationary phase allowing an exceptional separation of PAHs, including several isomer sets. Complete column specifications are listed in Table 1.

Table 1. SLB®-ILPAH Column Specifications

Purpose - This special purpose and specially tested capillary GC column is designed for the analysis of polycyclic aromatic hydrocarbons (PAHs). Each column is individually tested to ensure resolution of several key sets (phenanthrene / anthracene, benzo[a]anthracene / chrysene / triphenylene, and benzo [b]fluoranthene / benzo[k]fluoranthene / benzo[j]fluoranthene).

Stationary Phase - 1,12-Di(tripropylphosphonium) dodecane, non-bonded

Temp. Limits - Subambient to 300°C (isothermal or programmed)

^{See Figure 1}

Resolution Test

Every SLB-ILPAH column is tested to ensure it meets stringent resolution requirements for several sets of PAHs. Figure 1 depicts a chromatogram obtained from analysis of the QC test mix. All critical PAH isomers are baseline separated. The column efficiency is determined by measuring the theoretical plate value of naphthalene, in this case 109,480 plates have been obtained.

22-Component PAH Mix

PAHs need to be tested due to regulations of many authorities around the world ranging for sets of 16 to 24 PAHs. A 22-component PAH mixture of the most frequently listed PAHs was analyzed on a SLB®-ILPAH column (Figure 2). Beside of the separation of those isomers set, that was shown in the QC testing, this application demonstrates additionally the baseline separation of dibenz[a,h]anthracene (peak 16) and indeno[1,2,3-cd]perylene (peak 17), which cannot be achieved on conventional GC columns.

Conclusion

The main strength of ionic liquid GC columns is unique selectivity. For PAHs this ionic liquid column can achieve a level of separation not possible with conventional columns based on polysiloxane polymer or polyethylene glycol.

^{See Figure 2}

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