Simultaneous Determination of Cu, Zn and Fe in Honey by Use of Partial Least Square Regression PLS-2 Method

J. M. CAMIÑA; M.S. BOERIS; L.D. MARTINEZ; J. M. LUCO; E.J. MARCHEVSKY

CHEMIA ANALITYCZNA

POLISH CHEMICAL SOCIETY

Lugar: VARSOVIA; Año: 2004 vol. 49 p. 717 - 721

0009-2223

In this work, a simple and new spectrophotometric method for the simultaneous determination of Cu, Fe and Zn elements in honey by use of PLS-2 multivariate calibration method is proposed. An internal standard of Pr was incorporated to evaluate both adjustment of samples on PLS model and recuperation grade. The result obtained from honey samples was validated by ICP-AES method. 5-Br-PADAP [2-(5-Br-2-pyridylazo)]-5-diethylaminophenol was used as cromogenic agent which form coloured complexes with the elements studied at pH 9.2. The influence of chemical variables affecting the reaction as pH, tensoactive use, ionic strengh and interference was evaluated. Honey mineralization was carried out by acid attack with HNO3-HClO4 mixture in optimal definite proportions. 68 solutions for calibration set were prepared. Both, standard of calibration set and sample solutions, were measured between 400-650 nm wavelength range. The concentration ranges used in calibration set were the following: Cu(II) and Fe(III) 0.04-0.40 mg/L, Zn (II) 0.04-0.44 mg/L and Pr(III) 0.16-1.60 mg/L. In order to demostrate the capability of the proposed method, a set of three commercial honey samples was studied using ICP-AES. The relative error in the determination was less than 16 % in between both PLS and ICP-AES method in all cases. The recovery percentage was about 97 % in the mineralization step.