Sequential spectrofluorimetric determination of free and total glycerol in biodiesel in a multicommuted flow system

Autor(es)

Silva, Sidnei G. ^[1] ; Morales-Rubio, Angel ^[2] ; de La Guardia, Miguel ^[2] ; Rocha, Fabio R. P. ^[3]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Quim, BR-05513970 Sao Paulo - Brazil

^[2] Univ Valencia, Dept Analyt Chem, Burjassot Valencia 46100 - Spain

^[3] Univ Sao Paulo, Ctr Energia Nucl Agr, BR-13400970 Piracicaba, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ANALYTICAL AND BIOANALYTICAL CHEMISTRY; v. 401, n. 1, p. 365-371, JUL 2011.
• Citações Web of Science: 17

Resumo

A new procedure for spectrofluorimetric determination of free and total glycerol in biodiesel samples is presented. It is based on the oxidation of glycerol by periodate, forming formaldehyde, which reacts with acetylacetone, producing the luminescent 3,5-diacetyl-1,4-dihydrolutidine. A flow system with solenoid micro-pumps is proposed for solution handling. Free glycerol was extracted off-line from biodiesel samples with water, and total glycerol was converted to free glycerol by saponification with sodium ethylate under sonication. For free glycerol, a linear response was observed from 5 to 70 mg L(-1) with a detection limit of 0.5 mg L(-1), which corresponds to 2 mg kg(-1) in biodiesel. The coefficient of variation was 0.9% (20 mg L(-1), n = 10). For total glycerol, samples were diluted on-line, and the linear response range was 25 to 300 mg L(-1). The detection limit was 1.4 mg L(-1) (2.8 mg kg(-1) in biodiesel) with a coefficient of variation of 1.4% (200 mg L(-1), n = 10). The sampling rate was ca. 35 samples h(-1) and the procedure was applied to determination of free and total glycerol in biodiesel samples from soybean, cottonseed, and castor beans. (AU)

• Processo FAPESP: 08/01045-0 - Sistemas de análises em fluxo com multicomutação para a determinação de glicerol livre, manganês e carbono orgânico total em diferentes matrizes
• Beneficiário: Sidnei Gonçalves da Silva
• Modalidade de apoio: Bolsas no Brasil - Doutorado