title: Development of a flow system for the determination of cadmium in fuel alcohol using vermicompost as biosorbent and flame atomic absorption spectrometry.
abstract: In this study a method for the determination of cadmium in fuel alcohol using solid-phase extraction with a flow injection analysis system and detection by flame atomic absorption spectrometry was developed. The sorbent material used was a vermicompost commonly used as a garden fertilizer. The chemical and flow variables of the on-line preconcentration system were optimized by means of a full factorial design. The selected factors were: sorbent mass, sample pH, buffer concentration and sample flow rate. The optimum extraction conditions were obtained using sample pH in the range of 7.3-8.3 buffered with tris(hydroxymethyl)aminomethane at 50 mmol L(-1), a sample flow rate of 4.5 mL min(-1) and 160 mg of sorbent mass. With the optimized conditions, the preconcentration factor, limit of detection and sample throughput were estimated as 32 (for preconcentration of 10 mL sample), 1.7 microg L(-1) and 20 samples per hour, respectively. The analytical curve was linear from 5 up to at least 50 microg L(-1), with a correlation coefficient of 0.998 and a relative standard deviation of 2.4% (35 microg L(-1), n=7). The developed method was successfully applied to spiked fuel alcohol, and accuracy was assessed through recovery tests, with recovery ranging from 94% to 100%.
authors.affiliation: Departamento de Química, Universidade Federal de Santa Catarina, Florianópolis 88040900, SC, Brazil.
authors.forename: Joyce Nunes
authors.initials: JN
authors.lastname: Bianchin
authors.forename: Edmar
authors.initials: E
authors.lastname: Martendal
authors.forename: Renata
authors.initials: R
authors.lastname: Mior
authors.forename: Vanessa Nunes
authors.initials: VN
authors.lastname: Alves
authors.forename: Cleide Sandra Tavares
authors.initials: CS
authors.lastname: Araújo
authors.forename: Nívia Maria Melo
authors.initials: NM
authors.lastname: Coelho
authors.forename: Eduardo
authors.initials: E
authors.lastname: Carasek
mesh_terms: D000327:Adsorption; D000438:Alcohols / Q000592:standards*; D002104:Cadmium / Q000032:analysis*; D004736:Energy-Generating Resources / Q000592:standards*; D017022:Flow Injection Analysis; D015386:Hazardous Substances / Q000032:analysis; D052616:Solid Phase Extraction; D013054:Spectrophotometry, Atomic
chemical_list: D000438:Alcohols; D015386:Hazardous Substances; D002104:Cadmium