title: [Direct determination of lead and cadmium in soil by slurry-sampling graphite furnace atomic absorption spectrometry using matrix modification technique].
abstract: A method for the direct determination of lead and cadmium in soil by slurry-sampling graphite furnace-atomic absorption spectrometry using NH4 H2 PO4 as matrix modifier was developed. The effects of slurry stability, particle size of sample, matrix modifiers, ashing temperature, atomization temperature and common coexistent components on the signal intensities of lead and cadmium were investigated. The apparent activation energies of lead and cadmium were measured based on the linear relationship between the logarithm value of atomization peak time and atomization temperature. The mechanism of matrix modification was discussed. Under optimized conditions, the detection limit was 9.05 x 10(-10) g x mL(-1) for Pb and 1.76 x 10(-11) g x mL(-1) for Cd. The recoveries were in the range of 91%-97% for Pb and 93%-109% for Cd. The relative standard deviations were in the range of 4.2%-7.8%.
authors.affiliation: College of Chemistry and Environmental Science, Hebei University, Key Laboratory of Analytical Science and Technology of Hebei Province, Baoding 071002, China.
authors.forename: Han-Wen
authors.initials: HW
authors.lastname: Sun
authors.forename: Xiao-Hua
authors.initials: XH
authors.lastname: Wen
authors.forename: Shu-Xuan
authors.initials: SX
authors.lastname: Liang
mesh_terms: D002104:Cadmium / Q000032:analysis*; D007854:Lead / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis*; D013054:Spectrophotometry, Atomic / Q000295:instrumentation / Q000379:methods*
chemical_list: D012989:Soil Pollutants; D002104:Cadmium; D007854:Lead