GB/T 8143-2008Test methods of lac products (English PDF)

3.1 Method One

3.1.1 Principle

Determination of volatile matter (water) is treating the sample under specified conditions, calculated according to the sample weightlessness volatile matter content (moisture) of.

3.1.2 Instruments

3.1.2.1 weighing bottle

diameter 5cm, height 3cm.

3.1.2.2 dryer

diameter 15cm.

3.1.2.3

electric oven blast.

3.1.3 measurement program

In advance at 60 °C ± 1 °C weighed by sieve pore diameter of about 0.4mm (equivalent to 40 mesh) sample of about 2g, accurate to 0.1mg, placed

Constant weight weighing bottle, placed in 60 °C ± 1 °C oven dried 2h, remove and let cool to room temperature silica gel desiccator and weighed.

3.1.4 Calculation Results

Moisture mass fraction X1 and its value is expressed in%, according to equation (1).

X1 =

M1 2 m1 1-

M1 × 100 (1)

Where.

M1 --- weighing bottle and the sample values before drying mass in grams (g);

Numerical mass m1 2 --- weighing bottle and sample after drying, in grams (g);

--- Value m1 mass of the sample in grams (g).

The absolute difference between two independent test results obtained under repeatability conditions is not more than 0.2%. The arithmetic mean of the determination result.

3.2 Method Two

3.2.1 Principle

3.1.1.