Powered by Google-Search & Google-Books Chinese Standards Shop Database: 169760 (Sep 19, 2020)
HOME   Quotation   Tax   Examples Standard-List   Contact-Us   View-Cart
  

GBT14701-2019

Chinese Standard: 'GBT14701-2019'
Standard IDContents [version]USDSTEP2[PDF] delivered inStandard Title (Description)StatusRelated Standard
GB/T 14701-2019English130 Add to Cart 0--15 minutes. Auto immediate delivery. Determination of vitamin B2 in feeds Valid GB/T 14701-2019
GB/T 14701-2019Chinese16 Add to Cart <=1-day [PDF from Chinese Authority, or Standard Committee, or Publishing House]  

  Google-Books (Full-PDF will be auto-delivered in 0~10 mins):   GB/T 14701-2019  GB/T 13083-2018  GB/T 13884-2018  GB/T 14700-2018  GB/T 18633-2018
In 0~10 minutes time, full copy of this English-PDF will be auto-immediately delivered to your email. See samples for translation quality.  
GB/T 14701-2019
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 65.120
B 46
Replacing GB/T 14701-2002
Determination of vitamin B2 in feeds
饲料中维生素 B2的测定
ISSUED ON: JUNE 04, 2019
IMPLEMENTED ON: JANUARY 01, 2020
Issued by: State Administration for Market Regulation;
Standardization Administration of the People’s Republic of
China.
Table of Contents
Foreword ... 3 
1 Scope ... 4 
2 Normative references ... 4 
3 Method 1: Fluorescence spectrophotometry ... 4 
4 Method 2: High-performance liquid chromatography ... 8 
Appendix A (Informative) Vitamin B2 standard chromatogram ... 13 
Determination of Vitamin B2 in feeds
1 Scope
This Standard specifies the fluorescence spectrophotometry and high-
performance liquid chromatography for the determination of vitamin B2 (namely
riboflavin C17H20N10) in feeds.
Method 1 of this Standard is applicable to the determination of vitamin B2 in
animal and plant feed materials, compound feed and concentrated feed; the
quantitation-limit is 0.25 mg/kg.
Method 2 of this Standard is applicable to the determination of vitamin B2 in
vitamin premix feed, compound premix feed, and concentrated feed. When it is
detected by a fluorescence detector, the quantitation-limit is 5 mg/kg; when it is
detected by an ultraviolet detector, the quantitation-limit is 10 mg/kg.
For the determination of vitamin B2 in concentrated feed, method 1 is the
arbitration method; for the determination of vitamin B2 in vitamin premix feed
and additive premix feed, the high-performance liquid chromatography
fluorescence detector method of method 2 is the arbitration method.
2 Normative references
The following documents are indispensable for the application of this document.
For dated references, only the dated version applies to this document. For
undated references, the latest edition (including all amendments) applies to this
document.
GB/T 6682, Water for analytical laboratory use. Specification and test methods
GB/T 14699.1, Feeding stuffs. Sampling
GB/T 20195, Animal feeding stuffs. Preparation of test samples
3 Method 1: Fluorescence spectrophotometry
3.1 Principle
Vitamin B2 (riboflavin) produces green fluorescence under excitation of 440 nm
ultraviolet light; its fluorescence intensity is proportional to the riboflavin content
in a certain concentration range. Use sodium dithionite to reduce riboflavin to a
non-fluorescent substance; use the ratio OF the difference between the
3.2.11 Fluorescein standard solution
3.2.11.1 Fluorescein stock solution: weigh 0.050 g of fluorescein; use water to
dilute to 1 000 mL; place it in a brown bottle in the refrigerator at 2°C ~ 8°C to
store. The solution contains 50 μg/mL of fluorescein.
3.2.11.2 Fluorescein standard working solution: take 1 mL of fluorescein stock
solution (3.2.11.1); use water to dilute to 1 000 mL; place in a brown bottle in a
refrigerator at 2°C ~ 8°C to store. The solution contains 0.05 μg/mL of
fluorescein.
3.2.12 Bromocresol green pH indicator
Take 0.1 g of bromocresol green; add 2.8 mL of sodium hydroxide solution
(3.2.1) to dissolve; then, add water to dilute to 200 mL. The color-changing
range is pH 3.6~5.2.
3.3 Instruments and apparatuses
3.3.1 Analytical balance: sensitivity of 0.000 1 g.
3.3.2 Electric constant-temperature water bath.
3.3.3 Glass scale test tube with stopper: 15 mL.
3.3.4, Fluorescence spectrophotometer.
3.4 Sample preparation
According to the provisions of GB/T 14699.1, select at least 500 g of
representative sample; use quartering to reduce it to 100 g; prepare samples
according to GB/T 20195; grind; pass 0.425 mm hole sieve; mix well; place in
a sealed container; keep out of the sun and store at low temperature for use.
3.5 Test steps
The following operations shall be taken without strong light exposure.
3.5.1 Preparation of sample solution
Weigh 1 g ~ 2 g (accurate to 0.001 g) of feed materials, compound feed and
concentrated feed in a 100 mL brown conical flask. Add 65 mL of hydrochloric
acid solution (3.2.3); boil for 30 min in a boiling water bath. At the beginning of
the heating, shake the conical flask once every 5 min ~ 10 min, so as to prevent
the sample from agglomerating. After it is cooled to room temperature, use
sodium hydroxide solution (3.2.2) to adjust the pH to 6.0 ~ 6.5; immediately add
hydrochloric acid solution (3.2.4) to adjust the pH to 4.5 (bromocresol green
indicator becomes grass green). Transfer to a 100 mL brown volumet......
Related standard:   GB/T 14700-2018  GB/T 14702-2018
   
 
Privacy   ···   Product Quality   ···   About Us   ···   Refund Policy   ···   Fair Trading   ···   Quick Response
Field Test Asia Limited | Taxed in Singapore: 201302277C | Copyright 2012-2020