Contents lists available at ScienceDirect Microchemical Journal journal homepage: www.elsevier.com/locate/microc Cellulose-coated CoFe 2 O 4 nanoparticles as an adsorbent for extraction and preconcentration of bioactive compounds in vinegars ☆ Lucas Almir Cavalcante Minho a , Geovani Cardoso Brandão a , Débora de Andrade Santana a , Oseas Silva Santos b , Heloysa Martins Carvalho Andrade b , Walter Nei Lopes dos Santos a,b, ⁎ a Universidade do Estado da Bahia, Departamento de Ciências Exatas e da Terra, Cabula, 41195-001 Salvador, BA, Brazil b Universidade Federal da Bahia, Instituto de Química, Campus de Ondina, 40170-290 Salvador, BA, Brazil ARTICLEINFO Keywords: Spinel nanoparticles Biopolymer coat Phenolic acids Solid-phase extraction Multivariate optimization HPLC-DAD ABSTRACT In this work, an extraction and preconcentration fow system using mini-column packed with cellulose-coated CoFe 2 O 4 was developed for the determination of bioactive compounds in vinegar samples by high-performance liquid chromatography with diode array detector (HPLC-DAD). The CoFe 2 O 4 nanoparticles were synthetized by a sonochemical method and coated with cellulose biopolymer. Both synthetized nanoparticles and nano- composites were characterized employing the techniques of X-ray Difraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetry (TG) and Derivative Thermogravimetry (DTG). The fow system was optimized employing two-level full factorial design and Doehlert matrix, in which the established optimum conditions were: adsorbent mass of 254mg, eluent concentration of 92% (v/v methanol/water) and sampling fow rate of2.0mLmin −1 . In these conditions, the fow system allows the determination of 12 bioactive com- pounds with limits of detection and quantifcation that varied in the range of 0.0009–0.091mgL −1 and of 0.0028–0.276mgL −1 ,respectively.Enrichmentfactors(EF)wereintherangeof2.31–63.72.Theproposed fow system was applied for the analysis of 24 vinegar samples of brands locally available in Salvador City, Bahia, Brazil. 1. Introduction Bioactive compounds such as favonoids and phenolic acids are organic substances that are naturally present in several vegetable origin foods and beverages. It is know that the regular consume of foods and beverages, which contain bioactive compounds, may lead to preventing certain chronic diseases such cancers, cardiovascular and neurodegen- erative diseases, due to the antioxidant activity that these compounds have [1–6]. This way, the determination of bioactive compounds in foods is a relevant task in order to provide data on the nutritional composition of foods, contributing for a healthy dietary. However, these compounds may be present in trace concentration levels that make difcult its quantifcation, besides possible matrix interferences thatcanoccurduringtoanalysisduetothecomplexityoffoodsamples. Therefore, sample pretreatment steps are usually required before to instrumental analysis [7]. In general, vinegars are food products obtained from the alcoholic fermentation followed by acetous fermentation of any suitable raw material that contain carbohydrates, as fruit juices, wine, cider, malt, grains, sugarcane, among others. They are products widely consumed byseveralculturesaroundtheworldandhavevariousfoodapplications as seasoning or preservative agent in the preparation of sauces, ketchups and mayonnaise and are also consumed as a drink in some countries. The regular consumption of this food can provide several benefts to human health due to their functional properties such as antioxidant, antidiabetic, antitumor, antiobesity efects and prevention of cardiovascular diseases. These properties are due to presence of bioactive compounds in their composition as phenolic compounds, favonoids, anthocyanin and organic acids [8,9]. According to the literature, bioactive compounds in foods are fre- quently determined by following analytical techniques: UV/Vis mole- cular absorption spectrophotometry [2], high-performance liquid chromatography with diode array detector (HPLC-DAD) [3,4], high- performance liquid chromatography coupled to mass spectrometry (HPLC-MS)[10]andgaschromatographycoupledtomassspectrometry (GC–MS) [11]. The most these analytical techniques essentially require https://doi.org/10.1016/j.microc.2019.03.005 Received 2 November 2018; Received in revised form 28 February 2019; Accepted 1 March 2019 ☆ Selected paper from the 19th Brazilian Meeting on Analytical Chemistry and 7th Iberoamerican Congress on Analytical Chemistry, September 16–19, 2018, Caldas Novas, Goias, Brazil. ⁎ Corresponding author at: Universidade do Estado da Bahia, Departamento de Ciências Exatas e da Terra, Cabula, 41195-001 Salvador, BA, Brazil. E-mail address: wlopes@uneb.br (W.N.L. dos Santos). Microchemical Journal 147 (2019) 102–111 Available online 02 March 2019 0026-265X/ © 2019 Published by Elsevier B.V. T