title: Evaluation of lubricating oil preparation procedures for the determination of Al, Ba, Mo, Si and V by high-resolution continuum source FAAS.
abstract: Microwave-assisted acid decomposition and oil-in-water emulsification were evaluated as sample pretreatment procedures to determine Al, Ba, Mo, Si and V in lubricating oils by high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS). Average recoveries of Al, Ba and V in oil digests (107, 103 and 101%) were close to those obtained for emulsions prepared in kerosene medium (94, 113 and 95%). Average recoveries for Mo were close to 105 and 46% for emulsions and digests, respectively. Improved average recoveries (101%) were obtained for Mo in digests using the analyte addition technique. Silicon was successfully quantified only in digested samples. Limits of quantification for Al, Ba, Mo and V were 1.4, 31.5, 1.5 and 11.4-fold lower than those obtained by line-source FAAS. Enhanced sensitivity, multi-elemental capability, and high sample throughput are among the main advantages of HR-CS FAAS in comparison with the line-source FAAS technique.
authors.affiliation: São Paulo State University-UNESP, Department of Analytical Chemistry, Araraquara-SP, Brazil.
authors.forename: Volnei Resta
authors.initials: VR
authors.lastname: Amorim Filho
authors.forename: José Anchieta
authors.initials: JA
authors.lastname: Gomes Neto
mesh_terms: D000535:Aluminum; D001464:Barium; D004655:Emulsions; D054327:Lubricants; D008670:Metals / Q000032:analysis*; D008872:Microwaves; D008982:Molybdenum; D009821:Oils; D012825:Silicon; D013054:Spectrophotometry, Atomic / Q000379:methods*; D014639:Vanadium
chemical_list: D004655:Emulsions; D054327:Lubricants; D008670:Metals; D009821:Oils; D014639:Vanadium; D001464:Barium; D008982:Molybdenum; D000535:Aluminum; D012825:Silicon