Formation of methyl iodide from methoxyl-free compounds by hydriodic acid treatment

D/H ratios of methoxyl groups of the sedimentary organic matter of Lake Holzmaar (Eifel, Germany): A potential palaeoclimate/-hydrology proxy

“…This might show that during sample preparation other organic compounds, with less negative dD values than methoxyl groups, reacted with HI to form CH 3 I. Such interferences have previously been reported for methoxyl-free carbohydrates (Goto et al, 2005(Goto et al, , 2006. Indeed, Greule and Keppler (2011) pointed out that a contribution of CH 3 I from methoxyl-free carbohydrates should be considered when the lignin and pectin content of any sample was less than 3% of its total organic matter.…”

Structural Modification of Lignin in Peat during Peat Formation at Tropical Swamp

“…Acidic groups (phenolic hydroxyl and carboxyl groups) were quantified by the determination of methoxyl group contents after methylation with diazomethane followed by saponification with 0.5 M NaOH overnight at 40ºC 20 . Methoxyl group content was determined by a procedure developed by Goto et al 13 . Sample (20 mg) was soaked in 5 ml of concentrated HI (57%).…”

“…It was limited that chemical feature of lignin was investigated by spectrometric procedures such as cross polarization and magic angle spinning (CP/MAS) solid-state 13 C-NMR 11,16,39 and Fourier transform infrared (FTIR) 5,39 , analytical pyrolysis 37 and some chemical analyses as oxidative degradation using cupric oxide (CuO) of original peat samples.…”

“…In this study, peat samples collected from tropical peat swamps at Narathiwat Province, southern Thailand, were characterised by analytical methods used in plant cell wall science instead of procedures used in soil organic chemistry. An alkaline nitrobenzene oxidation 22 , an analytical ozonation 1 , methoxyl group 13 and acidic groups determination (carboxyl and phenolic hydroxyl groups) by diazomethane methylation 20 were applied to investigate aromatic composition, intermonomer linkages, the modification of aromatic moiety and the introduction of acidic groups of lignin in peat samples, respectively. In addition, lignin was isolated from peat sample according to Björk-man's procedure 3 to discuss in detail structural feature of lignin in peat and to understand process of modification of lignin during peat formation by spectroscopic procedures, such as 1 H-NMR, FTIR and UV spectroscopy.…”

A fast track for the accurate determination of methoxyl and ethoxyl groups in lignin

“…16,18,32,33 This approach allowed researchers to achieve values similar to the titrimetric method at a comparably low relative standard deviation (RSD, 2.5%). It was adapted for the analysis of ethoxyl groups in lignin by application of propyl iodide as the internal standard.…”