Determination of Polycyclic Aromatic Hydrocarbons (PAHs) in Leaf and Bark Samples of Sambucus nigra Using High-Performance Liquid Chromatography (HPLC)

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous organic compounds coming from natural or anthropogenic activities. Tree organs such as leaves and barks have been used to monitor urban air quality and have achieved remarkable ecological importance. However, the potential of many tree species as biomonitors is still unknown and efforts should be focused on conducting studies that analyze their capabilities with a viable analytical method. In this work, an analytical method for quantification of the 16 EPA priority PAHs from the leaves and bark of Sambucus nigra was validated. In general, the method showed good linearity, detection limits, precision, and recoveries, demonstrating that it is suitable for analyzing PAHs in both the leaves and bark of the Sambucus nigra species for which no analytical method for PAHs is yet available. The high prevalence of fluoranthene in the samples, which is a PAH related to coal combustion and biomass burning, and benzo[a]pyrene, which has a carcinogenic effect, was identified.

Keywords: HPLC; PAH; air pollution; biomonitoring; tree.

Figure 1

HPLC chromatogram of the certified standard at a concentration of 1000 μg L⁻¹ of 16 PAHs at λ = 230 nm, 220 nm, and 254 nm. Each PAH was calibrated in the UV wavelength (λ) where their signal was greatest.

Figure 2

HPLC chromatogram of the spiked bark sample at 1.5 μg g⁻¹ at λ = 230 nm, 220 nm, and 254 nm.

Figure 3

HPLC chromatogram of the non-spiked bark sample at λ = 230 nm, 220 nm, and 254 nm.

Figure 4

Experimental results for the non-spiked samples: (a) distribution of PAHs according to the molecular weight classification and (b) the individual PAH concentration.