Pipette-tip solid-phase extraction using polypyrrole as efficient adsorbent for extraction of avermectins and milbemycins in milk

Abstract

In this work, we developed a HPLC method for the multidetermination of avermectins (AVM) (abamectin-ABA 1b and ABA 1a, eprinomectin-EPR, and ivermectin-IVM) and milbemycins (moxidectin-MOX) in milk samples using polypyrrole (PPy) as adsorbent material in pipette-tip solid-phase extraction (PT-PPy-SPE). PPy was characterized by scanning electron microscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, and X-ray diffraction and the data agreed with the literature. The sample preparation included the clean-up of the milk by protein precipitation (PP) with acetonitrile and extraction of the analytes by PT-PPy-SPE. The chromatographic method was developed in reverse phase and isocratic mode with flow rate at 1.2 mL min and ultraviolet detection at 250 nm. The mobile phase composition was acetonitrile:methanol:water (55:25:20, v/v/v). The studied parameters and the optimized conditions for the sample preparation were washing solvent (300 μL water), volume and type of eluent (500 μL methanol), volume and pH of sample (1 mL and pH 10), amount of adsorbent material (50 mg PPy), and without addition of salt (NaCl). The method was linear over the concentration range from 20 to 3000 ng mL with coefficients of correlation (r) ≥ 0.99 for all analytes and recoveries around 100%. The method developed and validated was used for the analyses of real milk samples from cow treated with Ivomec (IVM 3.5%), in which were found 21.51 ± 2.94 ng mL of IVM. Finally, the results proved that PT-PPy-SPE coupled to HPLC-UV was economical, simple, and easy-to-perform technique. Graphical abstract Pipette-tip solid phase extraction using polypirrole as adsorbent material for determination of avermectins and milbemycins in milk.

Restricted access polypyrrole employed in pipette-tip solid-phase extraction for determination of nimodipine and nicardipine in breast milk

“…Besides, HMs showed an absorption band at around 1700 cm −1 referring to the bond CO and CAS showed a band at around 1683 cm −1 due to CN stretching, which confirms the presence of crosslinking between casein and glutaraldehyde and band attributed to the carboxylate group (O–C–O) at 1415 cm −1 . 20–22,27,28…”

“…Besides, HMs showed an absorption band at around 1700 cm −1 referring to the bond C]O and CAS showed a band at around 1683 cm −1 due to C]N stretching, which conrms the presence of crosslinking between casein and glutaraldehyde and band attributed to the carboxylate group (O-C-O) at 1415 cm −1 . [20][21][22]27,28 The TGA data evidenced that all materials were thermally stable at room temperature and curves showed two different thermal events for each material (Fig. 2b), but all presented a difference between them.…”

Development and validation of analytical methods by HPLC for quality control of avermectins and milbemycins in bulk samples

“…In conclusion, the compounds of series A are methoxylated at the 5-position, unlike the B-series with a hydroxyl group not derived from the same 5-position. AVMs are characterized by the presence of a substituent of a glucose molecule at position 13 and a sec-butyl substituent at carbon 25 (Milhome et al, 2009;Danaher et al, 2006;Hernández-Borges et al, 2007;Florez et al, 2018). Because of the lipophilic properties of the AVMs and the long-term permanence of their residues in the animals' bodies, especially in milk, they promote the risk of intoxication for consumers.…”

Intervención didáctica para la extracción y cuantificación de esteroides en orina

“…Palavras-chave: didática das ciências experimentais, prática laboratorial, preparação de amostras, SPE, HPLC Los procedimientos analíticos requieren técnicas de preparación de muestras como un paso esencial para obtener resultados confiables, lo cual garantiza la reproducibilidad y disminuye la profusión de errores, en pro de una confiabilidad estadística de los datos obtenidos (Alcántara-Durán et al, 2018;Angulo et al, 2018). En esta perspectiva, la microextracción en fase sólida emerge como una alternativa viable, en virtud de la rapidez del análisis, de la reducción de la muestra y de volúmenes de disolventes, de la simplicidad de su empleo, así como de sus posibilidades para su automatización (Liu et al, 2017).…”

“…La extracción en fase solida adaptada en puntera PT-SPE -pipette-tip solid phase extraction-es uno de los métodos más prometedores para la preparación de muestras miniaturizadas de extracción en fase sólida (Angulo et al, 2018;Jiang et al, 2018;Liu et al, 2017;Yang et al, 2017). Se diferencia de la SPE -solid phase extraction-convencional por precisar de una cantidad mínima de material adsorbente y no necesitar ningún dispositivo de extracción adicional, excepto una jeringa comercial.…”