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GB 5009.286-2022
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
National Food Safety Standard -
Determination of Natamycin in Foods
ISSUED ON. JUNE 30, 2022
IMPLEMENTED ON. DECEMBER 30, 2022
Issued by. National Health Commission of the People’s Republic of China;
State Administration for Market Regulation.
Table of Contents
Foreword... 3
1 Scope... 4
2 Principle... 4
3 Reagents and Materials... 4
4 Instruments and Equipment... 5
5 Analytical Procedures... 5
6 Expression of Analytical Results... 7
7 Precision... 8
8 Others... 8
Appendix A Liquid Chromatogram of Natamycin Reference Substance... 9
National Food Safety Standard -
Determination of Natamycin in Foods
1 Scope
This Standard specifies the method of liquid chromatography for the determination of
natamycin in foods.
This Standard is applicable to the determination of natamycin in cheese, processed cheese and
similar products, marinated meat products, meats (smoked, broiled and grilled), fried meats,
western-style ham, meat sausages, fermented meat products, mayonnaise, salad dressings,
cakes, fruit and vegetable juice (pulp), fruit juice drinks and fermented wines.
2 Principle
The sample is extracted or diluted with methanol. For the sample containing grease or solid
sample, add water to freeze it or centrifuge it to remove the fat or solid particle component in
the sample. After filtration, determine the extracting solution through reversed-phase liquid
chromatography and ultraviolet detector. Use the external standard method to quantify it.
3 Reagents and Materials
Unless it is otherwise specified, the reagents used in this Method are analytically pure; the water
is Grade-1 water specified in GB/T 6682.
3.1 Reagents
3.1.1 Methanol (CH4O). chromatographically pure.
3.1.2 Glacial acetic acid (C2H4O2).
3.2 Reference Substance
Natamycin (C33H47NO13, CAS. 7681-93-8). purity 98%, or reference substances certified by
the state and awarded with a reference substance certificate.
3.3 Preparation of Standard Solutions
3.3.1 Natamycin standard stock solution (250 mg/L). accurately weigh-take 25 mg of
natamycin reference substance (accurate to 0.1 mg); add an appropriate amount of methanol
and 1 mL of glacial acetic acid to perform ultrasonic dissolution; use methanol to reach a
Weigh-take 5.0 g of sample (accurate to 0.01 g); place it in a 50 mL centrifuge tube; add 15.0
mL of methanol to perform ultrasonic extraction for 20 min. Then, add 5.0 mL of water to mix
it up. At 4,000 r/min, centrifuge it for 10 min. In a refrigerator at 20 C, freeze it for 1 h. The
supernatant is filtered through 0.22 m organic syringe-type filter. Collect about 2 mL of the
filtrate and determine it on the instrument.
5.2.2 Pastry samples
Weigh-take 5.0 g of sample (accurate to 0.01 g); place it in a 50 mL centrifuge tube; add 15.0
mL of methanol to perform ultrasonic extraction for 20 min. Then, add 5.0 mL of water to mix
it up. At 4,000 r/min, centrifuge it for 10 min. The supernatant is filtered through 0.22 m
organic syringe-type filter. Collect about 2 mL of the filtrate and determine it on the instrument.
5.2.3 Fruit and vegetable juice (pulp), fruit juice drinks
Weigh-take 5.0 g of sample (accurate to 0.01 g); place it in a 50 mL centrifuge tube; add 15.0
mL of methanol to perform ultrasonic extraction for 20 min. At 4,000 r/min, centrifuge it for 10
min. The supernatant is quantitatively transferred to a 25 mL volumetric flask. Use water to
reach a constant volume and mix it up. Use 0.22 m organic syringe-type filter to filter it.
Collect about 2 mL of the filtrate and determine it on the instrument.
5.2.4 Fermented wines
Weigh-take an appropriate amount of the wine sample. Use 0.22 m syringe-type filter to filter
it. Collect about 2 mL of the filtrate and determine it on the instrument.
5.3 Instrument Reference Conditions
5.3.1 Chromatographic column. C18 chromatographic column (4.6 mm 250 mm, 5 m), or
equivalent.
5.3.2 Mobile phase. A. methanol, B. acetic acid + water = 5 + 95 (volume ratio).
5.3.3 Flow rate. 1.0 mL/min.
5.3.4 Detection wavelength. 305 nm.
5.3.5 Column temperature. 30 C.
5.3.6 Injection volume. 10 L.
5.3.7 The gradient elution procedure is shown in Table 1.
......
(Above excerpt was released on 2022-08-21, modified on 2022-08-21, translated/reviewed by: Wayne Zheng et al.)
Source: https://www.chinesestandard.net/PDF.aspx/GB5009.286-2022