0000000000134129
AUTHOR
Ana Paula S. Paim
Determination of total mercury in nuts at ultratrace level
Abstract Total mercury, at μg kg−1 level, was determined in different types of nuts (cashew nut, Brazil nuts, almond, pistachio, peanut, walnut) using a direct mercury analyser after previous sample defatting and by cold vapour atomic fluorescence spectrometry. There is not enough sensitivity in the second approach to determine Hg in previously digested samples due to the strong matrix effect. Mercury levels in 25 edible nut samples from Brazil and Spain were found in the range from 0.6 to 2.7 μg kg−1 by using the pyrolysis of sample after the extraction of the nut fat. The accuracy of the proposed method was confirmed by analysing certified reference materials of Coal Fly Ash-NIST SRM 1633…
Ultrasonic nebulization inductively coupled plasma optical emission spectrometry method for wine analysis
Abstract A methodology was developed to determine mineral elements in wines using Inductively Coupled Plasma Optical Emission Spectrometry combined with ultrasonic nebulization. The concentration of 36 elements (Al, B, Ba, Bi, Ca, Cd, Ce, Co, Cr, Dy, Er, Eu, Fe, Gd, K, La, Lu, Mg, Mn, Mo, Na, Nd, Ni, Pb, Pr, Sb, Sc, Sm, Sr, Tb, Ti, Tm, V, Y, Yb, and Zn) was determined in 59 wine samples and used to distinguish between Brazilian and Spanish wines. The best conditions for the plasma were selected using a two-level factorial design: radiofrequency power 1500 W; plasma gas flow rate 15 L min−1; auxiliary 0.70 L min−1; and nebulizer 0.40 L min−1. An exploratory multivariate analysis by Principal…
Determination of mercury in rice by cold vapor atomic fluorescence spectrometry after microwave-assisted digestion.
Abstract A cold vapor atomic fluorescence spectrometry method (CV-AFS) has been developed for the determination of Hg in rice samples at a few ng g−1 concentration level. The method is based on the previous digestion of samples in a microwave oven with HNO3 and H2O2 followed by dilution with water containing KBr/KBrO3 and hydroxylamine and reduction with SnCl2 in HCl using external calibration. The matrix interferences and the effect of nitrogen oxide vapors have been evaluated and the method validated using a certified reference material. The limit of detection of the method was 0.9 ng g−1 with a recovery percentage of 95 ± 4% at an added concentration of 5 ng g−1. The concentration level …