11—Observations on the Determination of Xylan in Jute

In the work described, the volumetric method of Kullgren and Tydén for the estimation of furfural has been modified, without using a catalyst, in order to make it more suitable for chemically treated jute. The modified method consists of treating the solution, adjusted to 1 per cent acid concentration, with bromide-bromate at 21 °C for 6·5 minutes and estimating the unreacted bromine.A comparative study of the modified volumetric and the standard phloroglucide procedures shows that variations in the method of distillation or estimation exert no significant effect on the yield of furfural.It has been shown that the presence of formaldehyde does not interfere with the determination of furfural by the modified volumetric procedure. Further, no formaldehyde was found to be liberated from jute-lignin under the condition of furfural distillation.The apparent yield of furfural from jute represents not only true furfural from xylan and polyuronides but also hydroxrmethylfurfural from hexose residues. The hydroxymethylfurfural content is found to be 1·2 per cent, 0·64 per cent being evolved from α-cellulose and the rest from hemicellulosesA rapid method for the accurate determination of xylan in jute has been developed by carrying out the distillation at a stretch and collecting 130 ml. of the distillate for analysis.