Synthesis of a molecularly imprinted polymer for the isolation of 1-hydroxypyrene in human urine

In the last decades, the assessment of polycyclic aromatic hydrocarbons' exposure has generated great interest and 1-hydroxypyrene (1-OHP) has been commonly used as a biological indicator of exposure to PAHs in many studies in environmental and occupational health. In this research, a molecularly imprinted polymer (MIP) was synthesised by precipitation polymerisation using 1-OHP as template, methacrylic acid (MAA) as functional monomer, ethylene glycol dimethacrylate (EGDMA) as cross-linker, and acetonitrile as porogen. MIP was used as solid-phase extraction (SPE) material for sample pretreatment and isolation of 1-OHP and posterior detection in a reversed-phase HPLC-FLD. Various parameters including washing solvent, elution solvent and volume affecting the extraction efficiency of the polymer have been evaluated to achieve the isolation of 1-OHP from urine samples and to reduce non-specific interactions. Cross-selectivity was studied in the presence of other structural analogues of the 1-OHP as hydroxyphenantrene isomers. The method was validated over a concentration range of 0.15-2.00 µg L(-1), R(2)>0.998. Recovery values were in the range of 78-90% and RSD <6.7%. The limits of detection and quantification were 0.05 µg L(-1) and 0.17 µg L(-1), respectively. In our knowledge, it is the first time that this methodology is applied for analysing urinary hydroxypyrene and it has been demonstrated that this specific MISPE-HPLC-FLD method offers a fast and simple alternative to determine 1-OHP in human urine samples.