Evaluation of a Multidimensional Solid-Phase Extraction Platform for Highly Selective On-Line Cleanup and High-Throughput LC−MS Analysis of Triazines in River Water Samples Using Molecularly Imprinted Polymers

Abstract

A novel highly selective sample cleanup procedure based on the use of molecularly imprinted polymers (MIPs) as solid-phase extraction materials has been evaluated with respect to its applicability and routine use in environmental analysis. The method comprises the combination of a restricted access material (RAM) and a MIP allowing a selective sample preparation to be achieved in the online mode. This combination is called the size-selective sample separation and solvent switch (six-SPE). The RAM column combines size exclusion and adsorption chromatography, reducing the concentration of matrix molecules by a cutoff of 15 kDa. The MIP column selectively retains the triazine analytes whereas the residual matrix is not retained and separated completely. Thus, the automated RAM-MIP is capable of excluding all matrix and nontarget compounds. The cleaned and enriched extract is subsequently eluted to an HPLC column and analyzed by LC-MS. A complete on-line analysis cycle including multidimensional solid-phase extraction, separation, and detection takes less than 15 min. Terbuthylazine, atrazine, propazine, simazine, ametryn, prometryn, irgarol, and also the metabolites deethylatrazine and deisopropylatrazine can be determined without any matrix interferences, e.g., by humic acids. The whole setup is fully automated and may be continuously operated. Nonspecific interactions with the polymer are below 1% in all cases. The accuracy of the LC-MIP-LC-MS system was controlled using a certified reference material (Aquacheck). The applicability of the method to the cleanup of real samples was demonstrated by injection of contaminated river water samples. The stability of different polymers was tested by consecutive injections, and it was shown that the performance of the materials did not vary even after more than 300 enrichment and desorption cycles.

Molecular imprinting science and technology: a survey of the literature for the years up to and including 2003

“…Nine chlorotriazine pesticides were trapped from river water samples on a C18-RAM (restricted access material) column and eluted with acetonitrile to a selective terbuthylazine-MIP column for final clean-up prior to LC-APCI-MS determination. 1176 Tramadol was similarly extracted from human plasma on a C18-RAM-tramadol-MIP system. 1177,1178 Using a C18-simazine-MIP coupled column system, several triazine herbicides could be extracted from water samples, apple extract and urine.…”

Probing trace levels of prometryn solutions: from test samples in the lab toward real samples with tap water

“…In fact, the use of SERS for prometryn in the literature has never gone below 10 -4 mol/L [24]. Prometryn detection with chromatography techniques has reached limits from 10 -6 to 10 -10 mol/L [31,32] while the differential pulse polarographic method led to detection of atrazine, prometryn, and simazine herbicides down to 8 9 10 -8 mol/L [7]. Oliveira-Brett et al [33] reported an electrochemical biosensor to investigate the interactions Fig.…”

“…The performance of SERS-based detection is competitive with a few works in the literature for detection of pesticides in real samples, most of them based on extraction and size exclusion methods in chromatography techniques [8,[34][35][36]. Koeber et al were able to detect triazine herbicides in river samples with a detection limit of 3.3 9 10 -10 mol/L for simazine by combining column size exclusion and adsorption chromatography [31]. Djozan et al reported detection of s-triazine herbicides in tap water with detection limit of 8.29 9 10 -8 mol/L using gas chromatography [37].…”

Emprego de polímeros de impressão molecular em preparo de amostras para análise de compostos orgânicos: aplicações e tendências

“…No entanto, alguns interferentes geralmente presentes nas amostras, como lipídeos e proteínas, podem diminuir dras-ticamente a seletividade destes polímeros [128] . Por outro lado, os materiais de acesso restrito (RAMs) apresentam uma excelente capacidade de eliminar a interferência de macromolécu-las apesar de serem pouco seletivos [129] . Neste contexto, foi proposta a associação de ambas as tecnologias, a fim de se obter um polímero seletivo para purificação de amostras complexas e, ao mesmo tempo, incapaz de se ligar a macromoléculas.…”