GB 5009.84-2016National food safety standard - Determination of vitamin B1 in foods (English PDF)

3.1 Reagents

3.1.1 n-butanol (CH3CH2CH2CH2OH).

3.1.10 Amylase. it shall not contain vitamin B1, enzyme activity >= 3700 U/g.

3.2 Reagent preparation

3.2.1 Potassium ferricyanide solution (20 g/L). WEIGH 2 g of potassium

ferricyanide, USE water to dissolve it, MAKE its volume reach to 100 mL,

SHAKE it uniformly. PREPARE it before use.

3.2.2 Sodium hydroxide solution (100 g/L). WEIGH 25g of sodium hydroxide,

3.2.6 Sodium acetate solution (0.05 mol/L). WEIGH 6.80 g of sodium acetate,

ADD 900 mL of water to dissolve it, USE glacial acetic acid to adjust the pH

between 4.0 to 5.0, ADD water to make the volume reach to 1000 mL. USE

0.45 µm microporous membrane to filter it before use.

3.2.7 Sodium acetate solution (2.0 mol/L). WEIGH 27.2 g of sodium acetate,

USE water to dissolve it, MAKE its volume reach to 100 mL, SHAKE it uniformly.

3.3 Standard substances

Vitamin B1 standard substance. thiamine hydrochloride (C12H17ClN4OS - HCl)),

CAS. 67-03-8, purity >= 99.0%.

3.4 Standard solution preparation

4.1 High performance liquid chromatograph with fluorescence detector.

4.3 Centrifuge. speed >= 4000 r/min.

4.6 Electric oven or autoclave.

5.1 Specimen preparation

5.1.1 Liquid or solid powder samples. Immediately after the sample is well-

mixed, MAKE determination in time or PRESERVE it in refrigerator.

5.1.2 Fresh fruits, vegetables and meat.

5.1.3 Other solid samples with lower moisture content. for example, the grain

having a moisture content at about 15%, TAKE about 100 g of sample, USE

crusher to crush the sample to obtain the power of constant uniformity, MAKE

determination in time or PRESERVE it in refrigerator.

5.2 Preparation of specimen solution

5.2.1 Test solution extraction

WEIGH 3 g ~ 5 g (accurate to 0.01 g) of solid sample or 10 g ~ 20 g of liquid

sample, PLACE it into a 100 mL conical flask (with a soft stopper), ADD 60 mL

of 0.1 mol/L hydrochloric acid solution, SHAKE it uniformly, PLUG the soft

stopper, PLACE it in the autoclave at 121 °C for 30 min. After finishing

hydrolysis and cooling it to below 40 °C, TAKE it out, SHAKE it gently for several

times; U

5.3 Instrument reference conditions

5.3.1 Column. C18 reversed-phase column (particle size 5 µm, 250 mm x 4.6

mm) or equivalent.

5.3.2 Mobile phase. 0.05 mol/L sodium acetate solution - methanol (65 + 35).

5.4 Standard curve production

INJECT the standard series working solution derivative into the high

performance liquid chromatograph to determine the corresponding peak area

of vitamin B1, USE the standard working solution concentration (µg/mL) as the

abscissa, the peak area as the vertical axis, to draw the standard curve.

5.5 Determination of the specimen solution

In accordance with the chromatographic conditions of clause 5.3, INJECT the

specimen derivative solution into a high performance liquid chromatograph to

obtain the peak area of vitamin B1, CALCULATE the concentration of vitamin

B1 in the solution to be determined in accordance with the standard curve.

10.1 Reagents

10.1.1 Butanol (CH3CH2CH2CH2OH).

10.1.8 Artificial zeolite.

10.1.9 Silver nitrate (AgNO3).

10.1.10 Bromocresol green (C21H14Br4O5S).

10.2 Reagent preparation

10.2.1 0.1 mol/L hydrochloric acid solution. PIPETTE 8.5 mL of hydrochloric

acid, USE water to dilute it, MAKE its volume reach to 1000 mL, SHAKE it

uniformly.

10.2.2 0.01 mol/L hydrochloric acid solution. MEASURE 50 mL of 0.1 mol/L

hydrochloric acid solution, USE water to dilute it, MAKE its volume reach to 500

mL, SHAKE it uniformly.

10.2.8 Potassium ferricyanide solution (10 g/L). WEIGH 1 g of potassium

ferricyanide, USE water to dissolve it, MAKE its volume reach to 100 mL,

SHAKE it uniformly, PRESERVE it in a brown bottle.

10.2.9 Alkaline potassium ferricyanide solution. PIPETTE 4 mL of 10 g/L

potassium ferricyanide solution (10.2.8), USE the 150 g/L sodium hydroxide

solution to dilute it to 60 mL, SHAKE it uniformly. PREPARE it before use, USE

it in dark.

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