title: Estimation of efficiency of processing soil samples for pesticide residues analysis.
abstract: The efficiency of four sample processing methods was tested with eight different types of soils representing the major proportion of cultivated soils. The principle of sampling constant was applied for characterizing the efficiency of the procedures and testing the well-mixed status of the prepared soil. The test material was 14C-labeled atrazine that enabled keeping the random error of analyses <or= about 1%. Adding water to the soil proved to be the most efficient and generally applicable procedure resulting in about 6% relative sample processing uncertainty for 20 g test portions. The expected error is inversely proportional to the mass of test portion. Smashing and manual mixing of soil resulted in about four times higher uncertainty than mixing with water. Grinding of soil is applicable for dry soils only, but the test procedure applied was not suitable for estimating a typical uncertainty of processing dry soil samples. Adding dry ice did not improve the efficiency of sample processing.
authors.affiliation: Pesticide Residue Analytical Laboratory, Plant Protection and Soil Conservation Service of BAZ County, Miskolc, Hungary. suszterga@caracom.hu
authors.forename: Gabriella
authors.initials: G
authors.lastname: Suszter
authors.forename: Arpád
authors.initials: A
authors.lastname: Ambrus
authors.forename: Marianna Schweikert
authors.initials: MS
authors.lastname: Turcu
authors.forename: Philipp Martin
authors.initials: PM
authors.lastname: Klaus
mesh_terms: D001280:Atrazine / Q000032:analysis*; D002250:Carbon Radioisotopes; D019411:Clinical Laboratory Techniques / Q000592:standards*; D008433:Mathematics; D010573:Pesticide Residues / Q000032:analysis*; D012494:Sampling Studies; D012680:Sensitivity and Specificity; D012989:Soil Pollutants / Q000032:analysis*
chemical_list: D002250:Carbon Radioisotopes; D010573:Pesticide Residues; D012989:Soil Pollutants; D001280:Atrazine