DETERMINATION OF LSORBOSE PREPARED BY BIOCONVERSIONAND RESIDUAL DSORBITOL IN IT BY DERIVATIVE

A derivative GC method with ntetracosane as the internal standard was developed for the determination of Lsorbose prepared by bioconversion and residual Dsorbitol in it. The method includes two procedures. The first procedure involves acetylation of bioconversion samples with a solution of acetic anhydride: pyridine(1∶1) at 90℃ for 20 min. The resulting products were assayed by GC to determine residual Dsorbitol. The second procedure involves reduction of the bioconversion samples with NaBH4 in aqueous solution at 40℃ for 1 hour followed by reaction with the mixture of acetic anhydride: pyridine(1∶1) at 90℃ for 20 min. The resulting products were assayed by GC to determine Lsorbose. Chromatography was performed on a 5% OV17 stainless steel column(2 m×3 mm ID) with nitrogen as carrier gas. The detector was FID. The standard curves of Dsorbitol and Lsorbose were linear in the ranges of 001999～2999 μg and 4000～24000 μg respectively. The method has been applied to assay Lsorbose and residual Dsorbitol in bioconversion products and to monitor bioconversion termination point of Lsorbose.