Determination of methanol residues in crude glycerol for animal feed by gas chromatography

Autor(es)

Nazato, Carina ; Romero, Alessandra de Cassia ; Abdalla, Adibe Luiz

• Tipo de documento: Artigo Científico
• Fonte: CIENTIA AGRICOL; v. 76, n. 6, p. 5-pg., 2019-11-01.

Resumo

Crude glycerol is a major by-product of biodiesel production and is an economical additive feed for ruminants. However, residual methanol in crude glycerol can be harmful to animal health. Several methods exist for quantifying methanol residues in biodiesel, yet few have been described that identify the methanol level in crude glycerol. We propose a method for determining the methanol level in crude glycerol destined for animal feed. Crude glycerol was extracted from the headspace and quantified by gas chromatography using a flame ionization detector (GC-FID). The method was linear up to 0.5 % of methanol. The limits of detection (LOD) and quantification (LOQ) were 0.015 and 0.031 %, respectively. No significant matrix effects were observed. Precision was 2 % at the 0.05 and 0.5 % levels. The average percentage of recovery was 90 %. Three analyzed samples of crude glycerol had methanol residues of 0.027-7.802 %. Furthermore, this methanol quantification method may be externally or internally calibrated using a GC manual injector. A reduction of at least 20 % in running time was obtained with good resolution between the peaks. Thus, this method can be applied to determine the methanol level in crude glycerol according to the upper limits for animal feed (5,000 ppm) and for human consumption (150 ppm). Finally, this method is useful for the quality control of crude glycerol intended for use in animal feed, enabling the alternative use of this by-product to add value to the biodiesel production chain. (AU)

• Processo FAPESP: 13/10630-1 - Análise de gossipol em coprodutos da indústria algodoeira e em produtos de origem animal destinados à alimentação humana
• Beneficiário: Alessandra de Cássia Romero
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 13/10359-6 - Validação de metodologia para a quantificação de metanol em glicerina bruta utilizada na alimentação animal
• Beneficiário: Carina Nazato
• Modalidade de apoio: Bolsas no Brasil - Mestrado