A poluição das águas por contaminantes emergentes afeta desfavoravelmente a saúde ambiental. O objetivo do presente estudo é estabelecer metodologia analítica para a avaliação da presença e da distribuição de acetaminofeno, ácido salicílico, diclofenaco e bisfenol-A em quatro rios que desembocam no complexo lagunar de Jacarepaguá. Foi desenvolvido um sistema de extração SPE automatizado para o processamento de amostras de grandes volumes. O estudo apresenta algumas oportunidades de melhoria do sistema SPE convencional, os diferenciais de qualidade referentes ao sistema desenvolvido, o fluxograma básico do projeto, o detalhamento dos componentes integrantes do sistema e as considerações para a operação. As extrações foram realizadas com cartuchos SPE Strata X. A metodologia analítica foi validada utilizando-se soluções simuladas de 1 L a partir dos compostos padrões em diferentes concentrações. Os extratos com os analitos foram injetados em cromatografia líquida de alta eficiência (CLAE) com detector ultravioleta (UV) considerando um método único para os quatro compostos devido à grande ocorrência em água residuais e superficiais. A validação da metodologia ocorreu com avaliação estatística dos resultados considerando linearidade, faixa de trabalho, limite de detecção instrumental, limite de quantificação instrumental, repetibilidade e recuperação. A recuperação media do acetaminofeno, ácido salicílico, bisfenol-A e diclofenaco nas amostras simuladas foi 10%, 71%, 80% e 73%, respectivamente. O sistema SPE desenvolvido foi utilizado para a extração dos analitos de amostras de águas superficiais de 5 pontos de amostragem distribuídos entre os rios Camorim, Arroio Pavuna, Grande e Arroio Fundo. O extrato obtido foi injetado em equipamento para a quantificação utilizando a técnica de cromatografia líquida de alta eficiência (CLAE) acoplada a espectrômetro de massas por tempo de vôo (MS-TOF). As concentrações dos compostos-alvo nos rios observados foram expressivas. O bisfenol-A foi o composto com maior ocorrência nos pontos de amostragem abordados

The pyrethroids bifenthrin, permethrin, cypermethrin and deltamethrin were extracted by solid phase extraction (SPE) and solid phase microextraction (SPME). The analysis were performed on a gas chromatograph with electron capture detection (GC-ECD). Octadecil Silano-C18, Florisil and Silica stationary phases were studied for SPE. Better results were obtained for Florisil which gave recoveries from 80% to 108%. Pyrethroids extraction by SPME showed a linear response and a detection limit of 10 pg ml-1. Although the data showed that the two extraction methods were able to isolate the pesticide residues from water samples, the best results were obtained by using SPME which is more sensitive, faster, cheeper, being a more useful technique for the analysis of pyrethroids in drinking water.

The detection of vitamin D in complex samples is challenging because of the instability of vitamin D in sample preparation. To resolve this problem, packed-fiber solid-phase extraction (PFSPE) has been successfully developed for the pre-treatment of samples containing vitamin D2 (D2) and vitamin D3 (D3) in dairy products. Based on PFSPE, vitamin D could avoid oxidation because of the shorter extraction time. The adsorbent materials, polystyrene/polypyrrole (PS/PPy) nanofibers, were prepared by electrospinning of PS and in situ polymerization of PPy on the surface of PS nanofibers. The linearity was within the range of 1-2000 ng mL−1 in dairy solution, and the recoveries were 91.9-109.1% with a relative standard deviation (RSD) < 13.6%. Therefore, the prepared method could be used for the detection of D2 and D3 in dairy products.

The leaf MeOH extract of Psychotria leiocarpa (Rubiaceae) showed in vitro non-cytotoxic and anti-dengue virus serotype 2 (DENV2) activity in human hepatocarcinoma cell lineage (HepG2). A one-step and cost-effective reversed-phase solid-phase extraction method based on high-performance liquid chromatography (HPLC) parameters allowed the isolation, directly from this bioactive extract, of the monoterpene indole alkaloids: N-glucopyranosyl vincosamide (1), vincosamide (2) and strictosidinic acid (3). The chemical structures were characterized based on 1D and 2D nuclear magnetic resonance (NMR), UV and high-resolution mass spectra (HRMS). The methodology has also allowed yielding a polyphenolic-rich fraction that was analyzed by high-performance liquid chromatography coupled to diode array detection and electrospray ionization tandem mass spectrometry (HPLC-DAD-ESI-MS/MS) revealing two flavonol triglycosides (4, 5) and three caffeoylquinic acid isomers (6-8). Compound 3 is reported for the first time in P. leiocarpa and all the phenolic compounds (4-8) are described for the first time in the genus Psychotria. Compounds 1-3 showed to be non-cytotoxic and anti-dengue active towards DENV2, highlighting vincosamide (2).

This work focuses on the validation and application of solid phase extraction followed by high-performance liquid chromatography (SPE-HPLC) analysis of important endocrine disruptors compounds (EDC) from different classes in highly complex wastewater matrix. The endocrine disruptors investigated included three different categories: pharmaceuticals (sulfamethoxazole (SMZ), trimethoprim (TMP) and diclofenac (DCF)), hormones (estrone (E1), 17α-ethinylestradiol (EE2) and 17β-estradiol (E2)) and plastic materials (bisphenol A (BPA)). The method involves pre-concentration by SPE using Strata-X extraction cartridges followed by HPLC coupled with diode array detector (DAD). As the assumption of homoscedasticity was met for analytical data, ordinary linear regression procedure was applied to the data. The method was considered validated for 7 EDC after consistent evaluation of the key analytical parameters. Recoveries were ranged from 52.3 to 179.6%. Limits of quantification were in the range 6.0-0.4 µg L−1. The described method was applied to evaluate the occurrence and removal efficiency of EDC in two biological sewage treatment plants (STPs). The influent mean concentrations of E1, E2 and EE2 hormones were 79.54; 175.09 and 102.19 µg L−1, respectively, while for SMZ, TMP, DCF and BPA were 215.17; 187.01; 218.97 and 87.12 µg L−1 for STP A, respectively. The efficiencies for the removal of EDCs ranged from 0 to 79.4%.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are a group of medications widely used by man to heal certain ailments. However, after consumption, they may be excreted in wastewaters with consequent environmental effects. NSAIDs are endocrine disruptors that can cause changes in animal physiology. The purpose of this study was to implement an analytical method that permits the determination of the presence of NSAIDs in water. Compound extraction was performed by solid-phase extraction (SPE) using an Oasis HLB cartridge. Analytes were analyzed by high-performance liquid chromatography with diode array detection (HPLC-DAD). The method was applied in water from the Maipo River and from a neighboring wastewater treatment plant in the Metropolitan Region of Pajaritos, Viña, Tuberia, Unión and Gansos sampling points in Chile. This method turned out to be adequate for the determination of NSAIDs in water samples with recovery percentages above 80%. Naproxen and ibuprofen were mostly detected in the Maipo River water samples, with concentrations ranging from 0.33 to 0.83 µg L-1.

This work reports the development of a methodology for the selective preconcentration of Cu(II) onto polyurethane foam (PUF) using the Eriochrome Black T (EBT) as ligand. The quantitative extraction of Cu(II) was achieved in a medium containing 60 mg L-1 of EBT and pH 1.5 (adjusted with HCl solution). The minimum time required to obtain total extraction of Cu(II) from solution was 30 min, when 200 mg of PUF were stirred with 100 mL of the samples. The recovery of Cu(II) from the solid-phase only could be performed by digesting the loaded PUF with concentrated HNO3 in a microwave oven (15 min, 600 W). The method was applied for the determination of trace concentrations of Cu(II) in waters by flame atomic absorption spectrometry. A recovery test was performed by spiking of the samples with 20 and 100 µg L-1 of Cu(II) and recovery percentages of 99.4-107% were obtained.

This study describes the development and optimization of a solid-phase extraction (SPE) method for analysis of ultraviolet (UV) filters, benzophenone-3 (BP-3), ethylhexyl methoxycinnamate (EHMC), ethylhexyl salicylate (ES) and octocrylene (OC), in environmental matrices. A 2(5-1) fractional factorial design (FFD) was used to evaluate the significant variables for the extraction method. The optimized experimental conditions determined from the statistical evaluation were: breakthrough volume of 500 mL, eluent of ethyl acetate, wash solvent of methanol (10% in water, v/v), eluent volume of 3 × 2 mL and pH 3. The evaluated analytical parameters were satisfactory for the analytes and showed linearity between 100 and 4000 ng L-1, recoveries for four fortification levels (Method Quantification Limit, 200, 1000 and 2000 ng L-1) were between 62 and 107% with relative standard deviations less than 14%. Limits of quantification were in the ng L-1 range and were between 10 and 100 ng L-1. The proposed method was used to analyze four UV filters in natural water samples.

A single run optimization chromatographic method for the determination of 15 emerging contaminants in surface water was optimized using solid-phase extraction (SPE) and high performance liquid chromatography (HPLC) with detection through ultraviolet-diode array (UV-DAD) or fluorescence (FLD). Selected compounds included acetaminophen, acetylsalicylic acid, diclofenac, ibuprofen, caffeine, 17β-estradiol, estrone, progesterone, 17α-ethynylestradiol, levonorgestrel, diethylphthalate, dibutylphthalate, 4-octylphenol, 4-nonylphenol and bisphenol A. Quality parameters of the proposed method showed a linearity r² > 0.996, coefficient of variation lower than 5%, recoveries between 80 to 120% for a spike of 10 µg L-1 for each of the 15 compounds. The lowest limit of detection (LOD) was 38 ng L-1 for caffeine, whereas the highest value was 170 ng L-1 for ibuprofen. The method was applied to the spatial and seasonal monitoring of these compounds in the Atibaia River, which is the main drinking water source for Campinas City (São Paulo State, Brazil). Among the 15 selected emerging contaminants, 10 were detected at least once. The lowest concentration determined was 0.096 µg L-1 for diclofenac, whereas caffeine showed concentrations as high as 127 µg L-1.

A simple confirmatory method for HPLC-UV determination of ketoconazole and clotrimazole residues in cow's milk after solid phase extraction (SPE) is reported in this article. The samples were deprived of proteins and lipids by treating with acetonitrile and consequent extraction in n-hexane. Extracts were further cleaned-up and concentrated via solid phase extraction. The analytes were determined quantitatively using a validated high performance liquid chromatography method. The method was linear in the range of 0.1-1.0 µg mL-1 for both analytes. Limits of detection and quantification for both analytes were equal to 0.01 and 0.1 µg mL-1, respectively. Important parameters influencing the extraction efficiency were investigated and then optimized; the proposed method was applied to the analysis of milk samples. Satisfactory recoveries were obtained in the range of 95.9-101.78% using SPE.