GB/T 18932.22-2003Method for the determination of fructose, glucose, sucrose, maltose contents in honey -- Liquid chromatography refractive index detection method (English PDF)

5.2 Analytical balance. two balances of which one's sensitivity is 0.1 mg, and

the other's sensitivity is 0.01 g.

5.3 Injector. 10 mL.

5.4 Organic phase filtration membrane. 0.45 µm.

5.5 Sample flask. 1.5 mL.

5.6 Volumetric flasks. 10mL, 25 mL, 50 mL, 100 mL.

6.1 Sample preparation

For non-crystalized laboratory sample, stir it evenly. For crystalized sample, in

a closed circumstance, place the crystalized sample in the water bath at no

more than 60°C; warm it; oscillate it till it is totally melted; stir it and cool it to

room temperature. Take 0.5 kg as the sample. Place the prepared sample in

the sample flask, seal and mark it.

6.2 Sample storage

Store the sample at room temperature.

7.1 Extraction

Weigh 5 g of sample, accurate to 0.001 g. Place it into a 50 mL beaker; add 30

mL of water. Use a glass rod to stir and make the sample completely dissolved.

Transfer it to a 100 mL flask. Use 10 mL of water to wash the beaker for three

times. Then transfer it to the aforementioned 100 mL flask. Use acetonitrile to

make the constant volume; mix it evenly. Use 0.45 µm filter membrane to filter

the sample solution into the sample flask for liquid chromatography.

7.2 Determination

7.2.1 Liquid chromatography conditions

a) Chromatographic column. carbohydrate analysis column 10µm,

300mm×3.9 mm (i.d);

b) Mobile phase. acetonitrile + water (77+23);

c) Flow rate. 1.0 mL/min;

Where,

X - component content in the determined sample, in grams per 100 grams

(g/100 g);

c - solution concentration of determined components, obtained from the

standard work curve, in grams per 100 milliliters (g/100 mL);

V - constant volume of sample solution, in milliliters (mL);

m - mass of weighed sample, in grams (g).

Note. The blank value shall be deducted from the result.

9.1 Repeatability

Under conditions of repeatability, the absolute difference between two

independent test results obtained shall not exceed the repeatability limit (r). The

content range of fructose, glucose, sucrose and maltose in honey and

repeatability equation are shown in Table 2.

Table 2 The Content Range, Repeatability Equation and Reproducibility

Equation

Name Content Range (g/100g) Repeatability Limit (r) Reproducibility Limit (R)

Fructose 21.31~39.62 r=–0.0095 m + 0.5420 lgR=0.4529 lgm – 0.5978

Glucose 20.54~36.15 r=–0.0094 m + 0.4127 lgR=0.0905 lgm – 0.4236

Sucrose 0.22~5.95 r=–0.0115 m + 0.1579 lgR=0.0011 m + 0.2149

Maltose 0.98~6.99 r=–0.0047 m + 0.1623 lgR=0.1474 lgm – 0.8122

If the difference exceeds the repeatability limit (r), then the test result shall be

discarded, and recomplete the determinations of two independent tests.

9.2 Reproducibility

Under conditions of reproducibility, the absolute difference between two

independent test results obtained shall not exceed the reproducibility limit (R).

The content range of fructose, glucose, sucrose and maltose in honey and

reproducibility equation are shown in Table 2.

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