Quantitative trace analysis of fullerenes in river sediment from Spain and soils from Saudi Arabia

A quantitative method based on ultrasound-assisted toluene extraction followed by liquid chromatography-electrospray ionization-tandem mass spectrometry for the analysis of C60 and C70 fullerenes, N-methylfulleropyrrolidine, [6, 6]-phenyl C61 butyric acid methyl ester and [6, 6]-thienyl C61 butyric acid methyl ester has been developed. The method was validated using fortified blank river sediments according to the criteria of Commission Decision 2002/657/EC. The method limits of detection ranged from 14 to 290 pg/g, making it suitable for its application in environmental analysis. The method has been applied to investigate fullerene content in 58 soil samples collected from different urban and industrial areas in Saudi Arabia and in river sediment from six different sites in the Llobregat River Basin. In addition, in the case of the Llobregat River, superficial water samples from the same sites of the sediments were collected and analysed using a previous method. In soils from Saudi Arabia, C60-fullerene was the only compound that was detected and quantified in 19% of samples. In the sediments of the Llobregat River, C60-fullerene was also the only one detected (33% of the samples), while in river water, C70-fullerene was the most frequent compound, and it was quantified in 67% of the samples. However, C60-fullerene was present in two of the six samples, but at higher concentrations than C70-fullerene, ranging from 0.9 to 7.8 ng/L.