title: A simple protocol to determine lignin S/G ratio in plants by UHPLC-MS.
abstract: A simple extraction protocol and an ultra-high performance liquid chromatography-mass spectrometry (UHPLC-MS) method for the determination of the syringyl/guaiacyl (S/G) ratio in lignin is reported herein. The method was entirely developed using stems of three Eucalyptus species, which were hydrolyzed with NaOH and partitioned with ethyl ether; vanillin (from the G monomer) and syringaldehyde (from S monomer) were quantified. The S/G ratios obtained were comparable to those usually reported for eucalyptus. The data for one of the eucalyptus species were compared with those obtained with a widely accepted method using thioacidolysis and gas chromatography-mass spectrometry (GC-MS). The method was also applied to sugarcane and showed to be reliable. The yield of the NaOH hydrolysis of the monolignols ranged from 89.94 to 95.69%, with more than 77.12% of recuperation in the liquid-liquid extraction. The whole analytical procedure was validated, achieving results with less than 4.38% of variation. The lowest LOD and LOQ were 0.01 and 0.05 μg/mL, respectively. In addition, the method combines reliability and a fast and direct quantification.
authors.affiliation: Department of Plant Biology, Institute of Biology, State University of Campinas, UNICAMP, 13083-970, Campinas, São Paulo, Brazil.
authors.forename: Joao Benhur
authors.initials: JB
authors.lastname: Mokochinski
authors.forename: Giovana Anceski
authors.initials: GA
authors.lastname: Bataglion
authors.forename: Eduardo
authors.initials: E
authors.lastname: Kiyota
authors.forename: Letícia Marrone
authors.initials: LM
authors.lastname: de Souza
authors.forename: Paulo
authors.initials: P
authors.lastname: Mazzafera
authors.forename: Alexandra Christine Helena Frankland
authors.initials: AC
authors.lastname: Sawaya
mesh_terms: D000465:Algorithms; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005052:Eucalyptus / Q000737:chemistry* / Q000145:classification; D008031:Lignin / Q000032:analysis* / Q000737:chemistry*; D013058:Mass Spectrometry / Q000379:methods*; D015203:Reproducibility of Results; D031786:Saccharum / Q000737:chemistry*; D012680:Sensitivity and Specificity; D013045:Species Specificity
chemical_list: C434470:guaiacyl monolignol; C434469:syringyl monolignol; D008031:Lignin