Determination of sulfur in biological samples using high-resolution molecular absorption spectrometry in a graphite furnace with direct solid sampling

作者：Ferreira Hadla S; Lepri Fabio G; Welz Bernhard^*; Carasek Eduardo; Huang Mao Dong

来源：Journal of Analytical Atomic Spectrometry, 2010, 25(7): 1039-1045.

DOI：10.1039/b925739j

The determination of sulfur in biological materials using high-resolution continuum source molecular absorption spectrometry and electrothermal vaporization of the carbon monosulfide ( CS) molecule has been investigated in detail using direct solid sampling. Best results have been obtained coating the platform with tungsten as a permanent modifier, adding 40 mu g Pd in solution as a chemical modifier, and the only sulfur compound that showed sufficient sensitivity and thermal stability to be used for calibration purposes under the conditions established for biological materials was thiourea. A pyrolysis temperature of at least 900 degrees C could be used and the optimum vaporization temperature was 2500 degrees C. Under optimized conditions a limit of detection of 0.015 mu g S absolute or 0.03 mg g(-1) S in the solid sample, based on a sample mass of 0.5 mg could be obtained; the characteristic mass was m(0) = 18 ng. Five certified biological reference materials have been analyzed using direct solid sampling and calibration against aqueous standards; the results were in agreement with the certified values on a 95% confidence interval.

• 出版日期2010