Chemometric applications to study the occurrence, ecological risk and bioaccumulation of emerging contaminants in Argentina

LESLY PARADINA FERNÁNDEZ; CARLA M. TEGLIA; PABLO GIORDANO; ROMINA BRASCA; MARÍA JULIA CULZONI; HÉCTOR GOICOECHEA

Estambul

Congreso; XX euro ANALYSIS; 2019

Nowadays, the concern about the occurrence of traces of emerging contaminants in the environment has increased [1]. These contaminants have impacts on the human health and the aquatic ecosystems, affecting both target and non-target organisms. Even though the presence of these compounds in water and soil samples has been revealed in several analytical studies worldwide, few reports described the occurrence and bioaccumulation of emerging pollutants in Argentina. During the chromatographic analysis of complex samples, several unknown substances that coelute are usually present. In these cases, selectivity may be mathematically restored by applying multivariate data analysis. In particular, the multivariate curve resolution-alternating least squares (MCR-ALS) algorithm is useful to model multiway analytical data of complex systems that, in addition, do not fulfill a trilinear model [2]. In the present work, the occurrence and associated ecological risk of fluoroquinolones were investigated in rivers and farm wastewaters of San Luis, Santa Fe, Córdoba, Entre Ríos and Buenos Aires provinces of Argentina by high-performance liquid chromatography (HPLC) coupled to fast-scanning fluorescence detection (FSFD), and data modeling by MCR-ALS, and ultra-high performance liquid chromatography (UHPLC) coupled to triple quadrupole mass spectrometry detection. The maximum concentrations of ciprofloxacin, enrofloxacin, ofloxacin, enoxacin and difloxacin in wastewater were 7.7, 11.9, 1.78, 22.1 and 14.2 μg L?1, respectively. In the case of river samples, only enrofloxacin was found at a concentration of 0.97 μg L?1. The individual risk to aquatic organisms associated with the water pollution due to fluoroquinolones was higher than 1 for some species. The proportion of samples classified as high risk was 87.5% for ofloxacin, 63.5% for enrofloxacin, 57.1% for ciprofloxacin and 25% for enoxacin. Secondly, the bioaccumulation and ecotoxicological effects of four antiretrovirals (lamivudine, stavudine, zidovudine and nevirapine) in tadpoles after 48h of exposure in aqueous solutions were studied. The analytical procedure involved a simple extraction method followed by UHPLC coupled to diode array detection (DAD) and MCR-ALS analysis for data processing. Under the studied conditions, the investigated analytes, in special nevirapine, showed possible bioaccumulation in tadpoles. In addition, the enzymatic biomarkers measured to evaluate the ecotoxicological effects displayed acethylcholinesterase activity similar to the control group, while the glutathione S-transferase activity was increased. In conclusion, the use of chemometric algorithms allows the prevalence evaluation of fluoroquinolones in water and the determination of antiretrovirals in tadpoles, providing information about concentration levels that could be potentially risky for the aquatic ecosystem, and harmful to biodiversity.