Optimized procedure for the determination of antimony in lipid-rich environmental matrices by flow injection hydride generation atomic absorption spectrometry

An analytical procedure for the reliable determination of Sb in digests of lipid-rich environmental matrices in the low ng l(-1)-range based on now in jection hydride generation atomic absorption spectrometry (FI-HG-AAS)has be en developed. Prior to HG-AAS, aliquots (250 to 320 mg) of dry samples were mineralized with 3 mi nitric acid and 0.5 mi of each sulfuric and perchlor ic acids in open digestion vessels made of glassy carbon in a heating block . Procedure detection and quantification limits of a previously developed p rocedure for the determination of Sb in plant materials by FI-HG-AAS were d ecreased with respect to the lower Sb concentrations in animal tissues, the sensitivity of the instrumental response was increased, and the compositio n of the acid digestion mixture was re-optimized for lipid-rich samples. Th e accuracy and precision of the developed procedure was evaluated by the an alysis of the two reference materials Bovine Liver 1577a and Pig Kidney CRM 186. These reference materials have been additionally spiked with appropri ate amounts of Sb to obtain recovery data. The solution detection limit (3 sigma) in digested samples was 0.021 sigma g l(-1), the detection limit for the whole procedure based on the dry powders was 7 pg g(-1), the method qu antification limit for a reliable determination of Sb was 23 pg g(-1). The reproducibility of repetitive measurements was 6.0% at 0.1 mu g Sb l(-1) an d 2.2% at 0.5 mu g Sb l(-1). Calibration curves were linear from 0.05 to 3 mu g Sb l(-1). To demonstrate the suitability of the developed method, conc entrations of Sb have been determined in pigeon eggs (similar to 2 ng Sb g( -1)), as well as in bream livers (similar to 4 ng g(-1)) and in deer livers (similar to 5 to 8 ng g(-1)) from animals living in remote and urban-indus trialized areas of Germany, respectively.