GB 5009.189-2016 English PDF (GB5009.189-2016)

This Standard specifies the method for determination of bongkrekic acid in foods such as tremella and its products, fermentative corn flour and its products. This Standard applies to determination of bongkrekic acid in foods such as tremella and its products, fermentative corn flour and its products.

GB 5009.189-2016
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
National Food Safety Standard -
Determination of Bongkrekic Acid in Foods
ISSUED ON: DECEMBER 23, 2016
IMPLEMENTED ON: JUNE 23, 2017
Issued by: National Health and Family Planning Commission of the PRC;
State Food and Drug Administration.
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Principle ... 4
3 Reagents and materials ... 4
4 Instruments and apparatuses ... 5
5 Analysis steps ... 6
6 Description of the analysis result ... 8
7 Precision ... 8
8 Others ... 8
Appendix A Liquid chromatogram of bongkrekic acid standard ... 9
National Food Safety Standard -
Determination of Bongkrekic Acid in Foods
1 Scope
This Standard specifies the method for determination of bongkrekic acid in foods such as tremella and its products, fermentative corn flour and its products. This Standard applies to determination of bongkrekic acid in foods such as tremella and its products, fermentative corn flour and its products.
2 Principle
The sample, which is extracted, purified, concentrated and filtered, is analyzed by the high performance liquid chromatography and quantified by the external standard method.
3 Reagents and materials
Unless otherwise specified, all the reagents in this method are analytical reagents, the water is grade-1 water that is specified by GB/T 6682.
3.1 Reagents
3.1.1 Methanol (CH3OH): chromatographic pure.
3.1.2 Glacial acetic acid (CH3COOH).
3.1.3 Ammonia solution (NH3·H2O).
3.1.4 Formic acid (CH2O2).
3.1.5 Hydrochloric acid (HCl).
3.1.6 Phosphoric acid (H3PO4).
3.1.7 Sodium bicarbonate (NaHCO3).
3.1.8 Petroleum ether: boiling range of 30°C ~ 60°C.
3.1.9 Absolute diethyl ether (C4H10O).
φ0.425 mm sieve, into a conical flask with a plug; add 20 mL of methanol; soak it at room temperature for 1 h; then, add 80 mL of trichloromethane and 0.2 mL of phosphoric acid solution (45.4%). Weigh 10 g (accurate to 0.01 g) of the fresh (wet) sample, which is cut and homogenized, into 16 mL of methanol; soak it at room temperature for 1 h; then, add 64 mL of trichloromethane and 0.16 mL of phosphoric acid solution (45.4%). Shake it for 30 min; filter. For the dry sample, take 50 mL of the filtrate; for the fresh (wet) sample, take 40 mL of the filtrate.
5.1.2.2 Extraction
Respectively transfer the above filtrate into a 150 mL separatory funnel; add sodium bicarbonate solution (40 g/L) of equal volume with the filtrate; shake for 2 min; let stand for layering; take the lower layer into another separatory funnel; then, use 10 mL of sodium bicarbonate solution (40 g/L) to repeat the extraction twice; shake gently; combine the three extracted sodium bicarbonate solutions; add 25 mL of
trichloromethane; shake for 2 min; let stand for layering; then discard the trichloromethane; slowly add hydrochloric acid solution (6 mol/L) to the separatory funnel to adjust the pH of the solution to 2~3; add 50 mL of petroleum ether (for fresh and wet sample, 40mL); shake for 3 min; let stand for layering; remove the petroleum ether layer to a rotary evaporator; then, respectively use 30 mL and 20 mL of petroleum ether to extract once (for fresh and wet samples, 20 mL); combine the petroleum ether layer into the same bottle; rotate-evaporate it to dryness in a water bath at 40°C ± 0.5°C; use a small amount of methanol to respectively transfer the extract in the rotatory evaporator to a 5.0 mL glass centrifuge tube or a concentrate bottle; use nitrogen to blow and concentrate it to dryness at 40°C ± 0.5°C; then, add 0.5 mL of methanol; rotate to dissolve; mix; filter it through a microporous organic filter for HPLC analysis.
5.2 Chromatograph reference conditions
Chromatograph reference conditions are listed as below:
a) Chromatographic column: C18 chromatographic column (with a column length of 250 mm, an inner diameter of 4.6mm, a particle size of 5 μm), or chromatographic columns of equivalent performance;
b) Mobile phase: methanol + water = 75 + 25; use glacial acetic acid to adjust the water to pH 2.5;
c) Flow velocity: 1.0 mL/min;
d) Column temperature: 30°C;
e) Detection wavelength: 267 nm;
f) Injection volume: 20 μL;