Fabio Antonio Cajamarca Suquila

Londrina State University | UEL · Department of Chemistry

The performance of three conventional treatments, including microwave-assisted acid digestion (MWAD), ultrasoundassisted extraction (UAE) and dry method (DAM) for determination of Cu2+ and Zn2+ in flaxseed meal, was evaluated. Quantification was performed by flame atomic absorption spectrometry (FAAS) and differential pulse anode stripping voltamme...

For years, researchers have focused on the determination of metal ions at trace levels in environmental and food samples using analytical methods that employ techniques with low cost acquisition and maintenance and without microwave-assisted acid digestion procedures or aggressive reagents. Therefore, the present study deals with the synthesis and...

Ion-imprinted polymers (IIPs) have been widely used in different fields of Analytical Sciences due to their intrinsic selective properties. However, the success of chemical imprinting in terms of selectivity, as well as the stability, specific surface area, and absence of swelling effect depends on fully understanding the preparation process. There...

The present study describes the development of a solid phase preconcentration method for cobalt determination at trace levels using cross-linked poly(vinylpyridine-co-protoporphyrin) as a highly efficient adsorbent and a hyphenated flow injection-FAAS system. The influence of molar amount of protoporphyrin and 4-vinylpyridine in the copolymer was s...

The development of a novel molecularly imprinted solid-phase extraction (MISPE) method for simultaneous preconcentration of imazapyr (IMP), imazapic (IMZ) and imazethapyr (IMT) with determination by HPLC-PAD (High performance liquid chromatography – photodiode-array detector) is proposed. The polymer synthesis was performed using imazethapyr as tem...

The present paper describes a new restricted access material-ion imprinted polymer for on-line preconcentration of Cd²⁺ from natural water samples, and simultaneous clean-up of humic acid. Cadmium-imprinted poly(allylthiourea) was synthesized and modified with 2-hydroxyethyl methacrylate (IIP-HEMA) to obtain the restricted access ability. The on-li...

ABSTRACT This work aims to evaluate the agronomic performance of crambe and juncea canola, sowed in the summer and winter season intervals with and without fungicide application. The cultivars used were FMS Brilhante and Terola 25A85 for crambe and juncea canola, respectively. The experimental design was randomized blocks in split plots, in which t...

Biodiesel is a renewable fuel derived from oilseeds or animal fats. Biofuel has low oxidative stability due to the high content of esters of unsaturated fatty acids, which are easily oxidized when exposed to air, light, heat and metals. Antioxidants are added to biodiesel to retard the oxidative process, which can capture free radicals making them...

A flow-injection preconcentration system using detection by the thermospray flame furnace atomic absorption spectrometry (FIA-TS-FF-AAS) is proposed. Cd2+ are adsorbed on avocado seed activated carbon (ASAC) packed into a cylindrical mini-column and eluted using HCl solutions for the detection system. A 2 5-1 fractional factorial and Doehlert matri...

A new on-line solid phase preconcentration method using an ion-imprinted polymer with restrict access material based on copper-imprinted poly(allylthiourea)modified with 2-hydroxyethyl methacrylate and bovine serum (IIP-HEMA-BSA)to preconcentrate Cu ²⁺ ions and exclude protein from milk samples via FIA-FAAS was developed. The samples were on-line p...

In the present paper, a new analytical preconcentration/speciation method for antimony species determination in bottled mineral water samples using the SiO 2 /Al 2 O 3 /SnO 2 adsorbent was developed. The method is based on selective adsorption of Sb(III) ions by SiO 2 /Al 2 O 3 /SnO 2 under a wide pH range (2.5–7.5). Total antimony was determined w...

Double imprinting process is fundamental to improvements in the adsorptive capacity of the molecularly imprinted polymers (MIP), but the effect of the surfactant type on adsorptive properties of the double-imprinted polymers are poorly understood. Thus, MIP to potassium diclofenac (PD) were developed and evaluated for their adsorbent properties. Po...

The aim of this study was to assess the 1000-seed weight (M1000) and oil content of seeds of canola (Brassica napus L.), safflower (Carthamus tinctorius), crambe (Crambe abyssinica Hochst), flax (Linum usitatissimum) and radish (Raphanus sativus L.), grown in fall/winter at four locations in the State of Parana (Brazil) with varying edaphoclimatic...

A new analytical method exploiting supramolecular solvent-based microextraction (SUPRAS) combined with ultrasound-assisted extraction to preconcentrate cadmium from medicinal plant, with further determination by thermospray flame furnace atomic absorption spectrometry (TS-FF-AAS), is proposed. The proposed method is based on the cadmium ultrasound-...

A new restricted access cadmium ion-imprinted poly(allythiourea) was synthesized and evaluated as sorbent for Cd²⁺ preconcentration with simultaneous exclusion of humic acid (HA). Restricted access medium-ion imprinted polymer was assessed by using the co-monomer 2-hydroxyethyl methacrylate (HEMA) as well as by surface coating with bovine serum alb...

The removal of Cr3+ from water solutions by biosorbents from the rind, endosperm, and endosperm + episperm of the Jatropha curcas was evaluated. Adsorption tests were performed in batch systems for evaluating the influence of the solution’s pH, adsorbent mass, contact time, initial Cr3+ concentrations, and solution temperature during the adsorption...

This paper describes the development of an electrochemical sensor highly selective to Pb2 + ions based on drop-coated glassy carbon electrode (GCE) with a suspension of ion imprinted polymer (IIP) loaded with 1-(2-pyridylazo)-2-naphthol (PAN) (IIP-PAN) and multi-walled carbon nanotubes (MWCNT). The polymer has been characterized by SEM and TGA. The...

In the present study, the synthesis and characterization of bifunctional organic–inorganic hybrid adsorbent for As(V) extraction in aqueous medium is described. The hybrid adsorbent was synthesized by coupling free radical addition with sol–gel processing, using 1-vinylimidazole (1-VI) as monomer, (3-aminopropyl)trimethoxysilane (APTMS) as amino f...

This work describes the synthesis and characterization of a new adsorbent nanocomposite based on multi-walled carbon nanotubes (MWCNTs) and polyvinylpyridine and its use in the development of a highly sensitive micro-flow injection preconcentration method coupled to TS-FF-AAS for the determination of very low levels of Cd. The characterization of t...

A new online solid phase preconcentration method using the new SiO2/Al2O3/SnO2 ternary oxide (designated as SiAlSn) as chelating agent free-solid phase extractor (CAF-SPE) coupled to flame atomic absorption spectrometry (FAAS) for Pb²⁺ determination at trace levels in different kind of samples is proposed. The solid adsorbent has been characterized...

In this study, a new method for the preconcentration of cadmium ions using modified aquatic macrophytes – Salvinia molesta as biosorbent in an on-line preconcentration system coupled to flame atomic absorption spectrometry (FAAS) was developed. The method is based on preconcentration of 20.0 mL sample at pH 3.75 through 35.0 mg of biosorbent at 10....