Abstract:

Sulfites in tremella were extracted with NaOH solution or by distillation with water, respectively, and determined using titration or spectrophotometry methods. Both extraction methods and determination methods were compared. The RSD (relative standard deviation) of distillation and extraction with NaOH solution were 1.364%－4.719% and 1.037%－4.480% respecitvely, and both were applicable for the extraction of sulfite. The recovery of titration was 79.41%－82.11%, and RSD was 0.231%－0.620% with the detection limit at 0.010 g/kg and 0.015 g/kg. Compared with titration, colorimetry method was not fit for accurate determination, with the recovery 79.08%－80.80%, RSD 0.609%－0.746% and detection limit at 1.2× 10-3 g/kg and 1.5×10-3 g/kg, and suitable for batch samples as it was less time-consuming.

Key words: tremella, sulfite, colorimetry, titration