[Determination of mannitol in health food by capillary gas chromatography].

To develop a capillary gas chromatographic method for the determination of mannitol in health food. Mannitol was extracted from the sample with water by ultrasonic wave. The aliquot of sample solution was acetylated to form mannitol hexacetate with lower boiling point. Then the derivative was separated with the use of SPB-608 capillary chromatographic column and determined by flame ionization detector (FID) at the column temperature of 180 degrees C, the detector temperature of 210 degrees C and the nitrogen flow rate of 30 mL/min. The linear range of this method was 0.05-10.00 mg/mL and the limit of detection of was 0.01 mg/mL. The within-day and between-days precisions were 4.4% and 7.3%-7.6%, respectively. The average recoveries were 84.6%-107.6%. Mannitol could be separated from glucose, inositol and sorbitol under the optimum chromatographic condition. The results demonstrate that the method has the advantages of simplicity, accuracy and sensitivity. It is suitable for the determination of mannitol in health food.