title: A multicommutated flow system for determination of bismuth in milk shakes by hydride generation atomic fluorescence spectrometry incorporating on-line neutralization of waste effluent.
abstract: A highly sensitive method was developed for determination of bismuth in milk shakes by multicommutation hydride generation atomic fluorescence spectrometry (HG-AFS) based on off-line sonication for 10 min with aqua regia 8% (v/v) and on-line waste treatment. The instrumentation and chemistry variables were studied in order to provide the best performance. The limit of detection in the original samples, established for a probability level of 99.6% (k = 3), was 1.67 ng/g Bi. The method provides a fast alternative in control analysis with a sampling throughput of 72 h as compared with 31 h obtained by the classical continuous measurement. Additionally, multicommutation reduces waste generation by a factor of 2.6. The consumption of sample, reductant, and blank, as compared with continuous mode HG-AFS, was reduced 9.6, 4.5, and 13.3 times, respectively. To confirm the accuracy of the method, recovery studies were performed, and excellent agreement between multicommutation and continuous measurement-based values was obtained. Application of the developed methodology for bismuth determination in milk shake samples from the Spanish market provided concentrations ranging from 4.2 to 15.0 ng/mL, and good comparability with data obtained by continuous measurements after microwave-assisted total digestion of samples for a 95% probability level and 12 degrees of freedom was found.
authors.affiliation: Universitat de València, Departamento de Química Analítica, Research Building, 50 Dr. Moliner St, 46100 Burjassot, València, Spain.
authors.forename: Josep F
authors.initials: JF
authors.lastname: Ventura-Gayete
authors.forename: Eva
authors.initials: E
authors.lastname: Rodenas-Torralba
authors.forename: Angel
authors.initials: A
authors.lastname: Morales-Rubio
authors.forename: Salvador
authors.initials: S
authors.lastname: Garrigues
authors.forename: Miguel
authors.initials: M
authors.lastname: de la Guardia
mesh_terms: D000818:Animals; D001729:Bismuth / Q000032:analysis*; D002417:Cattle; D008872:Microwaves; D008892:Milk / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013054:Spectrophotometry, Atomic
chemical_list: D001729:Bismuth