US EPA

6907891 

Journal Article 

CHROMATOGRAPHIC ANALYSIS OF POLYCYCLIC AROMATIC HYDROCARBONS BY H-ELECTRON CONTAINING POLYMERIC ORGANIC PHASE-GRAFTED ON SILICA 

Rahman, MM; Takafuji, M; Rana, AA; Mallik, AK; Gautam, UG; Ihara, H; , 

2009 

NOVA SCIENCE PUBLISHERS, INC 

HAUPPAUGE 

POLYCYCLIC AROMATIC HYDROCARBONS: POLLUTION, HEALTH EFFECTS AND CHEMISTRY 

265-294 

WOS:000278688900011 

Polycyclic aromatic hydrocarbons (PAHs) are well-known organic compounds derived from incomplete combustion of organic matters. PAHs have been widely studied in a broad field such as material science, industrial technologies and pharmaceutical sciences, as well known environmental pollutants, and an increasing particular concern has been paid to their adverse harmful effects to human due to the carcinogenic and mutagenic properties of many PAH species. Clearly, the concerns over adverse health effects of PAHs in human and wildlife provide the impetus for research on their sources, environmental fate and food chain transfer. High performance liquid chromatography (HPLC) is useful and conventional method to monitor PAHs. More than 60% of all HPLC separations are carried out under reversed-phase (RP) conditions and alkylated-silicas were successfully employed for the separation of mixtures of PAHs. In RP-HPLC chromatography, not only long alkyl chains but also aromatic compounds such as benzene, pyrene, and hetero aromatic selector such as vinylpyridine have been investigated for organic phase of stationary phase so far. However, development of new stationary phases has been required for separation of similar compounds such as structural isomers, positional isomers and optical isomers. In this review article, we focus on the chromatographic analysis of PAHs by pi-electron containing ordered and disordered polymeric organic phase-grafted silica. Polymeric phase-grafted silica stationary phases exhibits unexpected enhancement of separation for PAHs by a multiple-interaction mechanism, even if the polymer does not form any specific secondary structure. Poly(octadecylacrylate) and poly(4-vinylpyridine)-grafted mesoporous silica particles (Sil-ODA(n) and Sil-VPn respectively) will be described as typical examples of such stationary phases. Effects of grafting method and grafting-density of polymeric phases on the separation of PAHs in HPLC will be also discussed. Extensive chromatographic studies showed that selectivity for PAHs can be enhanced by multiple pi-pi interactions between the pi-electron containing polymeric phases and the guest PAL-Is molecules. The presence of aligned carbonyl groups in a crystalline state of poly(octadecylacrylate) on silica significantly enhanced the selectivity for PAHs by pi-pi interaction mechanism. However, Sil-VPn recognizes molecular shape (planar and disk-like) of PAHs through pi-pi interactions between pyridyl groups of grafted-polymer and PAHs, along with electrostatic interactions involving a inductive effects and /or a quadrupolar effect in the normal phase HPLC. Comparison of the HPLC separations for PAHs with conventional octadecylsilylated silica (ODS) demonstrates the efficiencies and effectiveness of these pi-electron containing polymeric organic phases grafted silica particles. 

Haines, PA; Hendrickson, MD; 

978-1-60741-462-9