title: The combination of infrared and microwave radiation to quantify trace elements in organic samples by ICP OES.
abstract: Sample-decomposition methods using microwave radiation in closed systems have been commonly used in the analysis of inorganic constituents; however, these methods are limited to small amounts of organic samples. This work proposes the combined use of infrared radiation and microwave radiation (IR-MW) to increase the amount of organic samples digested. The determination of Al, Ca, Cu, Fe, K, Mg, Mn, Na, P and Zn in human-feed samples was accomplished by ICP OES. The results were in agreement with those obtained from conventional decomposition by microwave radiation (closed system). The results obtained using the proposed IR-MW system for standard reference material (whole milk powder, NIST 8435) were also compared. Agreements of 85-100% were obtained for Al, Ca, Cu, Fe, K, Mg, Na, P and Zn in the standard reference material. The IR-MW system is simple to implement and cheap because it uses commercially available infrared lamps and allows the use of infrared radiation in the microwave-digestion vessel. Additionally, it is possible to reach better precision in the analysis of the human-feed samples using the IR-MW system. The proposed method also allows total digestion of large sample amounts or samples rich in organic compounds can also be performed in the IR-MW system using small volumes of nitric acid.
authors.affiliation: Laboratório de Estudos em Química Aplicada (LEQA), Departamento de Química Analítica e Físico-Química, Universidade Federal do Ceará, Campus do Pici, Fortaleza-Ce, Brazil.
authors.forename: A N S
authors.initials: AN
authors.lastname: Dantas
authors.forename: W O
authors.initials: WO
authors.lastname: Matos
authors.forename: S T
authors.initials: ST
authors.lastname: Gouveia
authors.forename: G S
authors.initials: GS
authors.lastname: Lopes
mesh_terms: D000818:Animals; D004867:Equipment Design; D005504:Food Analysis / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D007259:Infrared Rays; D008872:Microwaves; D008892:Milk / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013054:Spectrophotometry, Atomic / Q000379:methods*; D014131:Trace Elements / Q000032:analysis*
chemical_list: D014131:Trace Elements