GB/T 18872-2017 English PDF (GBT18872-2017)

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GB/T 18872-2017: Determination of vitamin K3 in feeds -- High performance liquid chromatography
GB/T 18872-2017
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 65.120
B 46
Replacing GB/T 18872-2002
Determination of vitamin K3 in feeds - High performance
liquid chromatography
ISSUED ON: NOVEMBER 01, 2017
IMPLEMENTED ON: MAY 01, 2018
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine;
Standardization Administration of the People's Republic of China.
Table of Contents
Foreword ... 3 
1 Scope ... 4 
2 Normative references ... 4 
3 Principle ... 4 
4 Reagents and materials ... 4 
5 Instruments and equipment ... 5 
6 Sampling and specimen preparation ... 6 
7 Analysis steps ... 6 
8 Result calculation ... 7 
9 Repeatability ... 8 
Annex A (informative) Example of labeled amount of feed sample, weighed sample
amount and dilution ratio of menadione extract ... 9 
Annex B (informative) Chromatogram of menadione standard solution ... 10 
Determination of vitamin K3 in feeds - High performance
liquid chromatography
1 Scope
This Standard specifies the high performance liquid chromatography for the
determination of vitamin K3 (menadione sodium bisulfite, nicotinamide bisulfite
menadione, dimethylpyrimidinol menadione sulfite, as menadione) in feeds.
This Standard applies to the determination of vitamin K3 in compound feeds,
concentrated feeds, additive premixed feeds and concentrate supplements. The limit of
quantification of the method is 0.4mg/kg.
2 Normative references
The following referenced documents are indispensable for the application of this
document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
GB/T 603, Chemical reagent - Preparations of reagent solutions for use in test
methods
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 Principle
The specimen is extracted with chloroform and sodium carbonate solution and
converted into free menadione. It is separated by reversed-phase C18 column, detected
by UV detector, and quantified by external standard method.
4 Reagents and materials
Unless otherwise stated, all reagents in this Standard are analytically pure. The test
water is in line with the requirements for grade three water in GB/T 6682.
Chromatographic water is in line with the requirements for grade one water in GB/T
6682. The solution is prepared according to GB/T 603.
6 Sampling and specimen preparation
Take representative feed samples according to GB/T 14699.1. Conduct down-sampling
by quartering.
Prepare specimens according to GB/T 20195. Grind. All pass through the 0.25mm hole
sieve. Mix well. Pack in an airtight container. Store at low temperature away from light.
7 Analysis steps
WARNING -- Because vitamin K3 is sensitive to air and ultraviolet light, and the
chloroform solution used as an extractant has certain toxicity, all operations
should be performed in a fume hood away from light.
7.1 Preparation of specimen solutions
Weigh 0.25g~0.5g of vitamin premix feed (accurate to 0.0001g) or 1g of compound
premix feed or 5g of concentrated feed (accurate to 0.001g), 5g~10g of compound feed
and concentrate supplement (accurate to 0.001g). Put into a 100mL conical flask with
stopper. Accurately add 50mL of chloroform (4.1) and place it on a rotary shaker (5.5)
for 2 min. Add 5mL of sodium carbonate solution (4.4) and rotate for 3 min. Add 5g of
diatomaceous earth and anhydrous sodium sulfate mixture (4.7). Shake on a rotating
shaker for 30 min. Then use medium-speed filter paper to filter (or transfer into a
centrifuge tube and centrifuge at 5000r/min for 10min).
Determine the aliquot amount according to the expected amount of the sample, the
weighing amount and the amount of the extract (see Table A.1). Accurately draw an
appropriate amount of chloroform extract (V2). Blow dry with nitrogen (or evaporate
to dryness at 40°C under reduced pressure). Use methanol (4.2) to dissolve. Set volume
(V3). Make the concentration of the specimen solution be 0.1μg~5μg of menadione per
ml. Filter through a 0.45μm organic filter membrane for analysis by high performance
liquid chromatography.
7.2 Determination
7.2.1 Reference chromatographic conditions
Chromatographic column: C18 type column; length is 150mm, inner diameter is 4.6mm,
particle size is 5μm, or analytical column with similar performance;
Mobile phase: methanol + water (75+25);
Flow rate: 1.0mL/min;
Column temperature: room temperature;