Showing papers by "Sandro Navickiene published in 2019"
TL;DR: In this article, the authors used liquid chromatography with ultraviolet diode array detection as the analysis technique for extraction of thiamethoxam, thiacloprid, thiophanate-methyl, teflubenzuron, and bifenthrin from the fruit of soursop (Annona muricata) using liquid-chromatography.
29 citations
TL;DR: Ulasonic solvent extraction was effective in the analysis of pesticides in roasted coffee and no residues of the pesticides were detected in the samples from a producer in Minas Gerais State, Brazil.
Abstract: Background: A simple and effective extraction method based on ultrasonic solvent extraction and liquid-liquid microextraction (as the cleaning step) was developed to determine seven pesticide residues in roasted coffee (Coffea arabica) using ultra-performance LC-tandem MS. Objective: Different parameters of the method were evaluated, including solvent type and amount and sonication time. The best results were obtained using 1.0 g roasted coffee and acetonitrile (5 mL) as the extraction solvent with sonication for 15 min. The method was validated using roasted coffee samples fortified with pesticides at different concentration levels (0.1, 0.2, 0.3, and 0.5 μg/kg). Average recoveries (three replicates) ranged from 74.3 to 99.9%, with RSDs between 0.7 and 10.2%. Results: The method showed good linearity for all the pesticides studied, with correlation coefficients >0.99. The detection limits ranged from 0.02 to 0.05 μg/kg, and the quantification limit for all the compounds was 0.10 μg/kg. The proposed method was applied for analysis of the compounds in commercial coffee samples from a producer in Minas Gerais State, Brazil. No residues of the pesticides were detected in the samples. Highlights: Ultrasonic solvent extraction was effective in the analysis of pesticides in roasted coffee.
7 citations
TL;DR: Magnesium silicate was effective as adsorbent for d-SPE step in the analysis of pesticides in beer and showed that magnesium silicate is an efficient alternative cleanup material to reduce analysis costs while maintaining the method reliability and accuracy.
Abstract: Background: Pesticides are applied for pest control during the production of cereal grains used in beer production. Given the risks for consumers, it is important to analyze the pesticide residues. Objective: Quick, easy, cheap, effective, rugged, and safe (QuEChERS)-based methods are very effective, and improvement in the cleanup step is an important approach. Methods: Primary secondary amine (PSA) and magnesium silicate were evaluated for dispersive-solid-phase extraction (d-SPE) cleanup step in extracts provided by the QuEChERS method in combination with GC-tandem MS for the determination of acetamiprid, terburfos, alachlor, ametryn, atrazine, azoxystrobin, carbofuran, carbosulfan, cypermethrin, deltamethrin, difenoconazole, esfenvalerate, flutriafol, thiamethoxam, and parathion-methyl in lager beer. Results: The amount of 50 mg of magnesium silicate was suitable for cleaning up beer extract as an alternative d-SPE material to PSA. The method was validated using beer fortified with pesticides at three concentration levels (0.002, 0.01, and 0.1 μg/mL). Average recoveries ranged from 70 to 123%, with RSDs between 0.3 and 10.5 %. Matrix effects were observed by comparing the slope of matrix-matched standard calibration with that of solvent. The method provided good linearity at the concentration levels of 0.001-2.5 μg/mL. Detection limits ranged from 0.0001 to 0.0007 μg/mL and quantification limits ranged from 0.001 to 0.006 μg/mL. The method was applied to nine beer brands. Conclusions: Results showed that magnesium silicate is an efficient alternative cleanup material to reduce analysis costs while maintaining the method reliability and accuracy. Highlights: Magnesium silicate was effective as adsorbent for d-SPE step in the analysis of pesticides in beer.
4 citations