title: Determination of some trace elements in food and soil samples by atomic absorption spectrometry after coprecipitation with holmium hydroxide.
abstract: The determination of trace elements in food and soil samples by atomic absorption spectrometry was investigated. A coprecipitation procedure with holmium hydroxide was used for separation-preconcentration of trace elements. Trace amounts of copper(II), manganese(II), cobalt(II), nickel(ll), chromium(lll), iron(Ill), cadmium(ll), and lead(ll) ions were coprecipitated with holmium hydroxide in 2.0 M NaOH medium. The optimum conditions for the coprecipitation process were investigated for several commonly tested experimental parameters, such as amount of coprecipitant, effect of standing time, centrifugation rate and time, and sample volume. The precision, based on replicate analysis, was lower than 10% for the analytes. In order to verify the accuracy of the method, the certified reference materials BCR 141 R calcareous loam soil and CRM 025-050 soil were analyzed. The procedure was successfully applied for separation and preconcentration of the investigated ions in various food and soil samples. An amount of the solid samples was decomposed with 15 mL concentrated hydrochloric acid-concentrated nitric acid (3 + 1). The preconcentration procedure was then applied to the final solutions. The concentration of trace elements in samples was determined by atomic absorption spectrometry.
authors: Erciyes University, Faculty of Education, Department of Elementary Education, 38039 Kayseri, Turkey. saracs@erciyes.edu.tr
authors: Sibel
authors: S
authors: Saracoglu
authors: Mustafa
authors: M
authors: Soylak
authors: Dilek
authors: D
authors: Cabuk
authors: Zeynep
authors: Z
authors: Topalak
authors: Yasemin
authors: Y
authors: Karagozlu
mesh_terms: D011232:Chemical Precipitation; D005504:Food Analysis / Q000379:methods*; D006695:Holmium / Q000737:chemistry*; D012987:Soil / Q000032:analysis*; D013054:Spectrophotometry, Atomic / Q000379:methods*; D014131:Trace Elements / Q000032:analysis*
chemical_list: D012987:Soil; D014131:Trace Elements; D006695:Holmium