Capillary Gas Chromatographic Separation Performances of a Tetraphenyl Porphyrin Stationary Phase

Yuan Yan,Jing Fan,Zitong Zhang,Zhen He,Lun Luo,Zhenzhong Wang

doi:10.3389/fchem.2022.800922

Abstract

Tetraphenyl porphyrin (TPP) has enormous potential for use as gas chromatography stationary phases because it has a distinctive extended π–π conjugated coplanar structure and a range of interesting properties such as a good solubility in dichloromethane, high melting point, and good thermal stability. In this work, a TPP column was successfully prepared using a static method. The column was nonpolar and had a high efficiency. The chromatographic selectivity of the TPP column was assessed. The TPP column showed superiority retention and higher resolution for alicyclic, aromatic molecules through ring matching and π-π stacking interaction comparable to HP-5MS column. The unique mechanisms through which the TPP column retained polychlorinated biphenyls allowed the peak pair of 2,2ʹ,5-trichlorobiphenyl and 4,4ʹ-dichlorobiphenyl to be resolved better on the TPP column than the HP-5MS column. The TPP column was thermally stable even at 260°C for 2 h and gave results of a high degree of precision (run-to-run and column-to-column) with relative standard deviations <0.05% and <4.96%, respectively. The results indicated that porphyrin derivatives will be useful gas chromatography stationary phases.

Highlights

Porphyrins are multifunctional aromatic macrocycles composed of homologs and derivatives of porphine with groups substituted on the outside ring
When the Tetraphenyl porphyrin (TPP) column was heated to 309°C, only 2% weight was lost. It indicated that the thermal stability of the TPP column was good enough to be the gas chromatography (GC) stationary phase
To verify uniformity of the entire length of the column, the cross-sections of several TPP capillary column segments at different positions were characterized by scanning electron microscopy (SEM) as well as the cross-sections of the NaCl particle coated inner wall of the capillary column for comparison

Summary

Introduction

Porphyrins are multifunctional aromatic macrocycles composed of homologs and derivatives of porphine with groups substituted on the outside ring. Various porphyrins can be synthesized by adding substituents with different structures and by adding different numbers of substituents at the meso- and β-positions of porphine (Figure 1) (Rothemund, 1935; Rothemund, 1936; Rothemund, 1939; Gottfried, 2015). The structures and properties of porphyrins make them important in various fields including medicine (Králová et al, 2010; Ethirajan et al, 2011), catalysis (Rezaeifard and Jafarpour, 2014; Zhao et al, 2019), the environment and energy(Goswami et al, 2018), and analytical chemistry (Biesaga et al, 2000; Paolesse et al, 2017; Masih et al, 2018). Porphyrins have been used to prepare materials for separating and enriching metal ions, peptides, phytosterols, and proteins in complex biological matrices(Hu et al, 2002; Jiang et al, 2017; Wang et al, 2017; Wei et al, 2017; Zhang et al, 2017; Zhang et al, 2018; Peng et al, 2019). Research employed Porphyrins combing with silica as stationary phases for liquid chromatographic separation of aromatic sulfonates, fullerenes, and Tetraphenyl Porphyrin Performance in GC polycyclic aromatic hydrocarbons (PAHs), but have given poor resolution and serious peak tailing (Kibbey and Meyerhoff, 1993; Xiao and Meyerhoff, 1996; Coutant et al, 1998; Biesaga et al, 1999; Chen et al, 2001)

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Results

Conclusion