Valid

GB 5009.252-2016National food safety standard - Determination of Levulinic Acid in Foods (English PDF)

食品安全国家标准食品中乙酰丙酸的测定

Preview PDF

This is a limited preview

Buy now to download the full PDF (12 pages)

Need quotation for your management?

Get a formal quotation for GB 5009.252-2016 in 30 minutes.

Issued by

National Health and Family Planning Commission of the PRC

Level / Type

National · Mandatory

Issue date

August 31, 2016

Implementation date

March 1, 2017

Scope

GB 5009.252-2016 is the English-translated version of 食品安全国家标准食品中乙酰丙酸的测定.

GB 5009.252-2016 is the Chinese standard "National food safety standard - Determination of Levulinic Acid in Foods". Its scope clause reads: This Standard specifies the method to use gas chromatography for the test of levulinic acid in foods.

This Standard applies to the test of levulinic acid in soy sauce, beverage (including carbonate beverage, coffee beverage, juice, milk beverage, vegetable protein beverage), sauce, honey, milk powder, biscuit, pastry, candy, jelly and flour product.

Method I -- Internal Standard Method. Its clauses include application scope; principle; reagents and materials; min; add 50 ml of ether; shake the mixture for 3 min ~ 5 min; let stand for about 10; 25 µm) or chromatographic column of similar model.; principle; reagents and materials; description of the analysis result.

It was issued by the National Health and Family Planning Commission of the PRC on 2016-08-31 and took effect on 2017-03-01.

Found what you need?

Document preview — GB 5009.252-2016

National Standard of the People's Republic of China

Issued by: National Health and Family Planning Commission of the PRC

Foreword...3
1 Application Scope...4
2 Principle...4
3 Reagents and Materials...4
4 Instruments and Apparatuses...5
5 Analysis steps...5
6 Description of the analysis result...7
7 Precision...7
8 Others...7
9 Principle...8
10 Reagents and Materials...8
11 Instruments and Apparatuses...9
12 Analysis steps...9
13 Description of the analysis result...10
14 Accuracy...11
15 Others...11
Appendix A Chromatogram of levulinic acid...12

Foreword

This Standard replaces SB/T 10417-2007, Method for Determination of beta-

acetylpropionic Acid in Soy Sauce.

Compared with SB/T 10417-2007, the major changes of this Standard are as follows:

-- Change the standard name into "National Food Safety Standard - Determination

of Levulinic Acid in Foods";

-- Extend the scope to soy sauce, beverage (including carbonate beverage, coffee

beverage, juice, milk beverage, vegetable protein beverage), sauce, honey, milk

powder, biscuit, pastry, candy, jelly and flour product;

-- Add reagents' grade and molecular formula;

-- Add preparation method of liquid sample and solid sample;

-- Add quantitation-limit of the determination method of levulinic acid in foods;

-- Modify the chromatogram.

National Food Safety Standard -

Determination of Levulinic Acid in Foods

1 Application Scope

This Standard specifies the method to use gas chromatography for the test of levulinic

acid in foods.

This Standard applies to the test of levulinic acid in soy sauce, beverage (including

carbonate beverage, coffee beverage, juice, milk beverage, vegetable protein

beverage), sauce, honey, milk powder, biscuit, pastry, candy, jelly and flour product.

Method I -- Internal Standard Method

2 Principle

After the sample is acidized, use ether to extract levulinic acid; use heptanoic acid as

the internal standard substance; use gas chromatography equipped with hydrogen

flame ionization detector to test; use internal standard method to quantify.

3 Reagents and Materials

Unless otherwise specified, all the reagents in this method are analytical reagents, the

water is grade-2 water specified by GB/T 6682.

3.1 Reagents

3.1.1 Anhydrous sodium sulfate (Na2SO4): burn for 4 h at 650°C; store in the dryer as

a standby.

3.1.2 Anhydrous ether (C4H10O).

3.1.3 Hydrochloric acid (HCl).

3.1.4 Sodium chloride (NaCl)

3.1.5 Ethyl acetate (C4H8O2): chromatographically pure.

3.2 Preparation of reagents

sodium chloride to wash for twice; discard the lower layer; for ether layer, use 30 g of

anhydrous sodium sulfate to dehydrate; concentrate to near-dryness at about 45°C;

use ethyl acetate to fix-volume to 10 mL; shake to mix well; use gas chromatograph

to test the sample.

5.1.2 Solid sample

Accurately weigh 5 g (accurate to 0.001 g) of fully pulverized sample into a 100 mL

test tube with plug; add 10 mL of saturated sodium chloride solution, 1.0 mL of

heptanoic acid standard stock solution, 3.0 mL of hydrochloric acid; shake-mix well for

1 min; add 50 mL of ether; shake the mixture for 3 min ~ 5 min; let stand for about 10

min ~ 15 min; after layering, extract the upper-layer ether extract into a 250 mL

separatory funnel; then, repeat the extraction twice, each time use 50 mL of ether;

combine the ether extract; use 10 mL of saturated sodium chloride solution to wash

twice; discard the lower layer; use 30 g of anhydrous sodium sulfate to dehydrate;

concentrate to about dryness at about 45°C; for ether layer, use ethyl acetate to fix-

volume to 10 mL; shake-mix well; use gas chromatograph to test the sample.

5.2 Gas chromatograph reference conditions

5.2.1 Chromatographic column: DB-WAX quartz capillary column (30 m × 0. 25 mm ×

0 25 µm) or chromatographic column of similar model.

5.2.2 Temperature of the sample injector: 270°C.

5.2.3 Temperature of the detector: 270°C.

5.2.4 Temperature-rise procedure: initial column-temperature is 120°C, maintain for 1

min; rise the temperature to 230°C at 8°C/min, maintain for 4 min.

5.2.5 Carrier gas: high-purity nitrogen; purity >= 99.999%; flow velocity: 1.0 mL/min.

5.2.6 Hydrogen flow velocity: 30 mL/min.

5.2.7 Air flow velocity: 300 mL/min.

5.2.8 Make-up gas flow velocity: 30 mL/min.

5.2.9 Injection method: split injection; split ratio: 25:1.

5.2.10 Injection volume: 1 µL.

5.3 Preparation of standard curve

Inject standard series working solutions into gas chromatograph separately; test the

corresponding peak areas of levulinic acid and internal standard substance; use

levulinic acid peak area / internal standard substance peak area as the vertical

ordinate, levulinic acid mass concentration as the abscissa, draw the standard curve.

Method II -- External Standard Method

9 Principle

After the sample is acidized, use ether to extract levulinic acid; use gas chromatograph,

equipped with hydrogen flame ionization detector, to conduct separation determination;

use external standard method to quantify.

10 Reagents and Materials

Unless otherwise specified, all the reagents in this method are analytical reagents; the

water used is grade-2 water specified by GB/T 6682.

10.1 Reagents

10.1.1 Anhydrous ether (C4H10O).

10.1.2 Anhydrous sodium sulfate (Na2SO4): burn for 4h at 650°C; store in the dryer as

standby.

10.1.3 Ethyl acetate (C4H8O2): chromatographically pure.

10.1.4 Hydrochloric acid (HCl).

10.1.5 Sodium chloride (NaCl).

10.2 Preparation of reagents

Hydrochloric acid solution (6 mol/L): measure 50 mL of hydrochloric acid; use water to

dilute to 100 mL.

10.3 Standard

Levulinic acid (C5H8O3): purity >= 99.5%.

10.4 Preparation of standard solution

10.4.1 Levulinic acid standard solution (5.00 mg/mL): accurately weigh 0.5 g of

levulinic acid (accurate to 0.000 1 g); use ethyl acetate to dissolve; fix-volume to a 100

mL volumetric flask; mix up well.

10.4.2 Levulinic acid standard series working solutions:

Respectively and accurately absorb 0.0 mL, 0.05 mL, 0.1 mL, 0.5 mL, 1.0 mL and 1.5

mL of standard stock solutions of levulinic acid (10.4.1) into 6 10 mL volumetric flasks;

× 0.25 µm) or chromatographic column of similar models.

12.2.2 Temperature of the sample injector: 260°C.

12.2.3 Temperature of the detector: 280°C.

12.2.4 Temperature-rise procedure: initial column temperature is 60°C, maintain for 1

min; rise the temperature to 220°C at 18°C /min; maintain for 1 min; rise the

temperature to 230°C at 10°C /min; maintain for 12 min.

12.2.4 Carrier gas: high purity nitrogen, purity >= 99.999%; flow velocity: 1.0 mL/min.

12.2.6 Hydrogen flow velocity: 30 mL/min.

12.2.7 Air flow velocity: 300 mL/min.

12.2.8 Make-up gas flow velocity: 30 mL/min.

12.2.9 Injection method: split injection; split ratio: 25:1.

12.2.10 Injection volume: 1 µL.

12.3 Preparation of standard curve

Inject standard series working solution into gas chromatograph separately; test the

corresponding peak areas; use the mass concentration of standard working solution

as the vertical ordinate, the corresponding peak area as the abscissa; draw the

standard curve.

See Figure A.2 for the gas chromatogram of levulinic acid standard solution.

12.4 Test of sample solution

Inject the sample solution into the gas chromatograph; obtain the corresponding peak

areas; get the mass concentration of levulinic acid in the to-be-test solution according

to the standard curve.

13 Description of the analysis result

Calculate content of levulinic acid according to Equation (2):

Where:

X -- the content of levulinic acid in the sample; the unit is mg/kg;

......

......
This preview omits tables, figures, formulas and parts of the technical clauses. The complete document — 12 pages — is available in the English PDF.

How to Download GB 5009.252-2016

1
Add to cart
Click "Download PDF" on this page and choose "Buy this standard". You can add more standards before checkout.
2
Checkout
Enter your email and billing details. Payment is processed securely by Stripe (cards or bank transfer). Prefer bank details? Request a quotation (min. order $300).
3
Instant delivery (0–9 sec)
Delivery is automatic: within seconds of payment you'll receive an email with a secure download link. The link stays valid for 72 hours.
4
Invoice included
A tax invoice is attached to the confirmation email. Need a custom invoice? Contact us.