title: Rapid determination of lead and cadmium in sewage sludge samples using electrothermal atomic absorption spectrometry with slurry sample introduction.
abstract: Lead and cadmium concentrations in sewage sludge samples are determined by suspending the ground samples in a solution containing 10% (v/v) concentrated hydrofluoric acid, 1% (v/v) concentrated nitric acid, 0.5% (m/v) dihydrogen ammonium phosphate and 0.1% (m/v) sodium hexametaphosphate. Aliquots of 20 microL of these suspensions (4 mg/mL) are diluted to 1000 microL with the same solution and then injected into the electrothermal atomizer. The drying stage is performed by programming a 400 degrees C temperature, a ramp time of 20 s and a hold time of 15 s on the power supply of the atomizer. No ashing step is used. Platform atomization is carried out at 1600 and 1800 degrees C for Pb and Cd, respectively. Calibration is performed using aqueous standards in the 5-75 and 0.2-5 microg/L Pb and Cd ranges, respectively. Results obtained for three certified reference materials and four samples demonstrate the reliability of the procedures described.
authors.affiliation: Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, Spain.
authors.forename: I
authors.initials: I
authors.lastname: López-García
authors.forename: P
authors.initials: P
authors.lastname: Viñas
authors.forename: J
authors.initials: J
authors.lastname: Arroyo-Cortéz
authors.forename: M
authors.initials: M
authors.lastname: Hernández-Córdoba
mesh_terms: D002104:Cadmium / Q000032:analysis*; D007854:Lead / Q000032:analysis*; D012680:Sensitivity and Specificity; D012722:Sewage / Q000737:chemistry*; D013054:Spectrophotometry, Atomic / Q000379:methods*
chemical_list: D012722:Sewage; D002104:Cadmium; D007854:Lead