D. Hennequin et al., Optimization and experimental designs methodology in atomic absorption spectrometry: Rapid determination of copper traces in butter, ANALUSIS, 26(8), 1998, pp. M25-M30
Traces of copper in emulsified fats are determined directly by atomic absor
ption spectroscopy with electrothermic atomization (AAS-EA) after dispersio
n of the sample in a BTA/water/THF (48/12/40) mixture and without previous
acidic digestion. The two significant factors of the thermic program: char-
ashing ramp (factor X-1 = 40 s) and atomization temperature (factor X-2 = 2
450 degrees C) were optimized by means of a centered composite plane. A fai
r agreement is obtained between calibration in a "reconstituted butter" mat
rix (anhydrous butter oil and water) and calibration in simple medium. The
detection limit is about 3 ppb and the sensibility expressed in characteris
tic mass is about 7 pg/0.0044 U.A. The thermic program is well-suitable for
the analysis of butter when increasing the char-ashing temperature to 900
degrees C. The calibration is carried out in a butter matrix with a detecti
on limit of 7 ppb and sensibility of 17 pg/0.0044 U.A.