Multivariate optimisation of an ultrasound assisted-matrix solid-phase dispersion method combined with LC-fluorescence detection for simultaneous extraction and determination of aflatoxins in pistachio nut samples.
This paper describes the application of ultrasound-assisted matrix solid-phase dispersion as an extraction and clean-up procedure for aflatoxins (B1, B2, G1 and G2) and subsequent determination by LC-fluorescence detection. A Box-Behnken design was used to determine the parameters influencing the extraction procedure through response surface methodology and experimental design. The influence of different variables including type of dispersing phase, sample-to-dispersing phase ratio, type and quantity of clean-up phase, ultrasonication time, ultrasonication temperature, nature and volume of the elution solvent were investigated in the optimisation study. C18, graphitic carbon black and acetonitrile were selected as dispersing phase, clean-up phase and elution solvent, respectively. The optimised values were sample-to-dispersing phase ratio of 1:1, 50 mg of graphitic carbon black, 11 min ultrasonication time, 30°C ultrasonication temperature and 3 ml acetonitrile. Under the optimal conditions the limits of detection (LODs) were ranged from 0.04-0.11 µg kg(-1) and the relative standard deviations (RSDs) of the extraction method were less than 8.6%. The recoveries of the matrix solid-phase dispersion process ranged from 74% to 78% with relative standard deviation lower than 9% in all cases. Finally, the matrix solid-phase dispersion was successfully applied to extraction of trace amounts of aflatoxins in pistachio samples.
a Department of Chemistry, Central Tehran Branch , Islamic Azad University , Tehran , Iran.
Mahboobeh
M
Manoochehri
Ali Akbar
AA
Asgharinezhad
Mahdi
M
Safaei
D000348:Aflatoxins / Q000032:analysis*; D000704:Analysis of Variance; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005470:Fluorometry; D005504:Food Analysis / Q000379:methods*; D005506:Food Contamination / Q000032:analysis; D017633:Magnesium Silicates; D009754:Nuts / Q000737:chemistry*; D027927:Pistacia / Q000737:chemistry*; D015203:Reproducibility of Results; D052616:Solid Phase Extraction / Q000379:methods*; D014465:Ultrasonics
D000348:Aflatoxins; D017633:Magnesium Silicates; C005013:Florisil