FAAS determination of metal nutrients in fish feed after ultrasound extraction

Instituto de Biociências, Departamento de Física e Biofísica – UNESP, Caixa Postal 510, 18618-000 Botucatu, SP, Brazil
Food Chemistry (Impact Factor: 3.39). 03/2009; 113(2):679-683. DOI: 10.1016/j.foodchem.2008.07.070


This paper proposes a method to determine calcium, magnesium, manganese and zinc in fish feed samples using ultrasound in the analyte extraction process, and subsequent quantification by flame atomic absorption spectrometry (FAAS). Using 0.10 mol/L of HCl as extraction solution, the optimal conditions of extraction were established as follows: 100 mg of sample mass; sample granulometry of less than 60 μm; sonication time of three cycles of 10 s and sonication power of 102 W. The method was applied in studies of the digestibility of these nutrients in samples of fish feed used in the diet of Nile tilapia juveniles. The results achieved were congruent with those obtained from the mineralization of fish feed samples in the metal nutrient extraction process.

Download full-text


Available from: Mayra A. D. Saleh
  • Source
    • "The muscle tissue samples of each fish species studied were mineralized using a procedure previously described in the literature (Neves et al., 2009; Silva, Padilha, Pezzato, Barros, & Padilha, 2006; Silva et al., 2007) with several modifications, as described below: approximately 250 mg (weighed in triplicate using an analytical scale, accurate to hundredths of a milligram) of the fish muscle tissue was transferred to a 25 mL digestion flask. Concentrated sulfuric acid (3 mL) and 30% (w/w) hydrogen peroxide (1 mL) were transferred to each digestion flask. "
    [Show abstract] [Hide abstract]
    ABSTRACT: In the present study, a simple, rapid and sensitive method was developed for the determination of mercury concentrations in the muscle tissue of fish from the Brazilian Amazon using graphite furnace atomic absorption spectrometry (GFAAS) following acid mineralization of the samples in an ultrasonic cold water bath. Using copper nitrate as a chemical modifier in solution and sodium tungstate as permanent modifier, we were able to attain thermal stabilization of the mercury up to the atomisation temperature of 1600°C in the GFAAS assay. The calculated limits of detection (LOD) and quantification (LOQ) were 0.014 and 0.047mgkg(-1), respectively.
    Full-text · Article · Dec 2013 · Food Chemistry
  • Source
    • ", less than 75 μm [25], or less than 60 μm [26]. For UPSS, a particle size less than 100 μm has been recommended [27] "
    [Show abstract] [Hide abstract]
    ABSTRACT: In this work, two ultrasound-based procedures are developed for sample preparation prior to determination of P, K, Ca, Cr, Mn, Fe, Ni, Cu, Zn, As, Se and Sr in biological tissues by total reflection X-ray fluorescence spec-trometry. Ultrasound-assisted extraction by means of a cup-horn sonoreactor and ultrasonic-probe slurry sampling were compared with a well-established procedure such as magnetic agitation slurry sampling. For that purpose, seven certified reference materials and different real samples of animal tissue were used. Similar accuracy and precision is obtained with the three sample preparation approaches tried. Limits of detection were dependent on both the sample matrix and the sample pre-treatment used, best values being achieved with ultrasound-assisted extraction. Advantages of ultrasound-assisted extraction include reduced sample handling, decreased contamination risks (neither addition of surfactants nor use of foreign objects inside the extraction vial), simpler background (no solid particles onto the sample carrier) and im-proved recovery for some elements such as P. A mixture of 10% v/v HNO 3 + 20–40% v/v HCl was suitable for extraction from biological tissues.
    Full-text · Article · Jan 2012 · Spectrochimica Acta Part B Atomic Spectroscopy
  • Source
    • "ples of laboratory - reared tilapia fingerlings were transferred to 50 ml polypropylene flasks and stored at À20 C . All were prepared for the copper extraction step by dehydration in a lyophiliser for 48 h followed by grinding in a porcelain mortar and pestle in the presence of liquid nitrogen until reduced to a particle size of less than 60 mm ( Neves et al . 2008 , 2009 ) . Laboratory equipment The samples were dehydrated in a Christ Alpha 2 – 4 LD Plus ( Nova Analitica , Sao Paulo , SP , Brazil ) freeze - drying system over a period of 48 h in three stages ."
    [Show abstract] [Hide abstract]
    ABSTRACT: The purpose of this work was to determine the concentration of copper in samples of farmed Nile tilapia (Oreochromis niloticus L.) fillets purchased in the city of Botucatu (São Paulo, Brazil) and in fillet and liver samples of Tilapia fed diets supplemented with different concentrations of Cu from the Laboratory of Aquatic Organism Nutrition/FMVZ-UNESP (Botucatu, Brazil). The fillet samples were prepared by lyophilisation and cryogenic grinding into particles smaller than 60 µm, and copper was extracted ultrasonically using 0.10 mol l(-1) HCl as extraction solution. Copper determination was performed by graphite furnace atomic absorption spectrometry (GFAAS) with optimised temperatures of drying, pyrolysis, atomisation and cleaning. Palladium nitrate was injected into the samples as a chemical modifier and tungsten as a permanent modifier. Copper concentrations of 0.70-1.60 mg kg(-1) were found, which are in line with Brazilian regulations. The accuracy and precision of the copper concentrations determined in this study were evaluated using certified standard Lake Michigan fish tissue (NIST SRM 1947).
    Full-text · Article · Dec 2011 · Food Additives and Contaminants: Part B Surveillance
Show more