Sample preparation methods for determination of Cd, Pb and Sn in meat samples by GFAAS: use of acid digestion associated with a cold finger apparatus versus solubilization methods
Abstract
The nitric-perchloric acid digestion, 22.070(b) and 22.073, for the determination of phosphorus in grains and stock feeds was compared with three other methods of sample preparation (destruction of organic material) : quinoline molybdate precipitation, perchloric-sulfuric-sodium molybdate digestion, and the plant method. The values obtained by the nitric-perchloric acid method were not in good agreement with those obtained by the other methods studied. Six samples of commercial feeds and one barley sample were analyzed. The barley sample gave very poor recoveries by method 22.073.
Abstract
Four sample preparation methods (dilute acid digestion, concentrated acid digestion, alkali fusion, and low temperature ashing) for the determination of fluoride in vegetation are compared. A fluoride ion selective electrode is used for the final quantitative measurements. Ionic strength and pH are maintained by a concentrated citrate buffer. The highest sensitivity and reproducibility are obtained by low temperature ashing of the dry sample. Several vegetables, grown in the neighborhood of a glaze factory, were simultaneously analyzed by 2 of the methods, the dilute acid digestion and the low temperature ashing procedures. The higher fluoride content found with the latter technique is attributed to the complete mineralization of the sample.
AbstractVarious sample preparation methods for Energy Dispersive X-ray Fluorescence (EDXRF) analysis of Portland cement were compared in order to evaluate improvement in analytical accuracy and precision. Sample preparation requirements for EDXRF are slightly different than for Wavelength Dispersive X-ray Fluorescence (WDXRF), and the methods commonly used in WDXRF are not optimized for EDXRF. Primarily, the work focuses on techniques for producing a fused sample with the lowest practical concentration of lithium borate flux. Determination of minimum detection limits were made from samples with varying proportions of flux in order to evaluate analytical optimization. Ease and reproducibility of preparation of the sample was also considered.
Evaluation of sample preparation methods based on alkaline and acid solubilization for the determination of Na and K in meat samples by atomic spectrometric techniques