title: Fast ultrasound-assisted extraction of copper, iron, manganese and zinc from human hair samples prior to flow injection flame atomic absorption spectrometric detection.
abstract: A dynamic ultrasound-assisted extraction procedure utilizing diluted nitric acid was developed for the determination of copper, iron, manganese and zinc in human hair taken from workers in permanent contact with a polluted environment. The extraction unit of the dynamic ultrasound-assisted extraction system contains a minicolumn into which a specified amount of hair (5-50 mg) is placed. Once inserted into the continuous manifold, trace metals were extracted at 3 mL min(-1) with 3 mol L(-1) nitric acid under the action of ultrasound for 2 min for zinc and 3 min for copper, iron and manganese determination, and using an ultrasonic water-bath temperature of 70 degrees C for zinc and 80 degrees C for copper, iron and manganese determination. The system permits the direct analysis of hair and yields concentrations with relative standard deviations of <3% (n = 11). The applicability of the procedure was verified by analysing human hair samples from workers exposed to welding fumes, and its accuracy was assessed through comparison with a conventional sample dissolution procedure and the use of a certified reference material (BCR 397, human hair).
authors.affiliation: Department of Analytical Chemistry, Nutrition and Bromatology, Faculty of Chemistry, University of Santiago de Compostela, 15782, Santiago de Compostela, Spain. qncayebi@usc.es
authors.forename: M C
authors.initials: MC
authors.lastname: Yebra-Biurrun
authors.forename: R M
authors.initials: RM
authors.lastname: Cespón-Romero
mesh_terms: D003300:Copper / Q000032:analysis; D017022:Flow Injection Analysis; D006197:Hair / Q000737:chemistry*; D006801:Humans; D007501:Iron / Q000032:analysis; D008345:Manganese / Q000032:analysis; D019216:Metals, Heavy / Q000032:analysis*; D016273:Occupational Exposure / Q000032:analysis*; D012015:Reference Standards; D013010:Sonication; D013054:Spectrophotometry, Atomic / Q000379:methods*; D014896:Welding; D015032:Zinc / Q000032:analysis
chemical_list: D019216:Metals, Heavy; D008345:Manganese; D003300:Copper; D007501:Iron; D015032:Zinc