High-throughput chemometrically assisted flow-injection method for the simultaneous determination of multi-antiretrovirals in water

Abstract

This work is focused on the simultaneous determination of different nucleosides (lamivudine, abacavir, zidovudine) and non-nucleoside (nevirapine, efavirenz) reverse transcriptase inhibitors (antiretrovirals) in river, tap and well water by pH-gradient flow-injection analysis with diode-array detection (FIA-DAD) and further multivariate curve resolution-alternating least square (MCR-ALS) processing. Previous to the development of the analytical method with quantitative purpose, the acid-base characterization was conducted for all the analytes by determination of the experimental pKa. The pKa values, obtained by UV spectrometric titration coupled to MCR-ALS data modeling, were in agreement with those found in the literature, and, interestingly, a non-reported pKa of 12.27 was identified for nevirapine. Eventually, the analytical method was developed and its performance on the quantitation of the antiretrovirals was evaluated through its application to validation and environmental samples. The recovery studies showed values between 85 and 115% with relative errors of prediction below 10%. The figures of merit were satisfactory for all the studied drugs, with limits of detection between 25 and 40 μg L−1. Therefore, the proposed method, which is based on the generation of high-throughput data, is a simple and suitable alternative to determine the concentration of antiretroviral drugs in complex matrices, without pre-concentration or extraction steps. Additionally, MCR-ALS demonstrated to be a useful tool for solving mixtures of analytes with high spectral overlapping, in the presence of unknown interferences.