MULTIVARIATE-ANALYSIS; TRACE-METALS; CLASSIFICATION; POLLUTION; CHEMOMETRICS; COMBINATION; DIGESTION; SAMPLES

Laser-induced breakdown spectroscopy (LIBS) is an emerging, multi-elemental and green technique, particularly suitable for the direct analysis of solid samples. In this study, thirty-two superficial sediments collected from Cienfuegos Bay in 2011-2013 were analyzed by LIBS without requiring sample digestion. Al, Ca, Fe, K, Mg, Mn, Na and Ti emission lines were detected in all samples. The full LIBS spectra of the samples were subjected to principal component analysis (PCA) and hierarchical cluster analysis (HCA). Most samples showed a similar emission signal pattern, whereas two samples collected in 2012 and another two in 2013 showed anomalously higher emission signals for Na, Mg and Ca, Mg, respectively. In three of the sediments, the impact of external factors on the ecosystem is the presumable cause of the observed anomalies. The combination of LIBS with multivariate data analysis demonstrated a high capacity for the fast detection of anomalous metal compositions in marine sediments.