Sudan red belongs to azo series chemical synthetic dyes, not food additives, mainly including four types of â… , â…¡, â…¢ and â…£. For the detection of Sudan red in food, China has issued GB / T 19681-2005 National Standard for High-Performance Liquid Chromatography for the Detection Method of Sudan Red Dye in Food. After the sample was purified by solvent extraction and solid phase extraction, it was analyzed by reversed-phase high-performance liquid chromatography-ultraviolet visible light detector and quantified by external standard method.
Method advantages
After the chili powder sample was extracted with n-hexane, it was then purified using a solid phase extraction column for ProElut SDH Sudan red detection, and detected by high performance liquid chromatography. This method refers to the national standard method for sample extraction. The purification process uses a commercial solid phase extraction column for Sudan red detection. There is no need to follow the national standard method for chromatographic column packing and neutral alumina activity adjustment to avoid neutral oxidation The activity of aluminum is easily affected by the environment and causes the drawback of unstable recovery rate of Sudan Red. The reproducibility and recovery results of the solid phase extraction column for ProElut SDH Sudan Red detection are more stable and reliable. The detection limit of the method is 5 μg / kg, which is better than the minimum detection limit of 10 μg / kg required by the national standard GB / T 19681-2005.
The following is a detailed solution, please refer to it!
1. Scope of application
This scheme is suitable for the detection of Sudan Red I, Sudan Red II, Sudan Red III and Sudan Red IV in chili powder. The detection limit of the method is 5 μg / kg.
2. Extraction
(1) Take 1.0 g of sample and mix with 10 mL of n-hexane, shake for 5 min, ultrasonically extract for 5 min, centrifuge at 8000 rpm for 2 min, collect the supernatant
(2) Repeat the extraction of the lower residue with 10 mL of n-hexane according to step (1), and combine the two supernatants;
(3) The supernatant was distilled under reduced pressure to near dryness in a 40 ℃ water bath, and then 5 mL of n-hexane was added to mix, to be purified.
3. Purification-ProElut SDH 6 mL (Cat. # 65909)
a Activation: 5 mL n-hexane activation;
b loading: add the liquid to be purified, discard the effluent;
c. Rinse: add 5mL n-hexane, 5mL 1% ethyl acetate n-hexane, and discard the effluent
d Elution: add 10 mL of 30% ethyl acetate n-hexane, collect the effluent;
e Re-dissolved: The eluent was distilled to near dryness at 40 ℃ under reduced pressure, and made up to 1 mL with 40% methyl tert-butyl ether n-hexane solution for HPLC analysis.
4. Chromatographic conditions
Column: Diamonsil C18 (2), 250 mm × 4.6 mm, 5 μm (Cat # 99603)
Flow rate: 1.0 mL / min
Injection volume: 20 μL
Column temperature: 40 ℃
Detector: PDA 518 nm
Mobile phase: A: 0.2% phosphoric acid aqueous solution B: acetonitrile
Related product information for the determination of Sudan red dye in chili powder:
Fantastic Pens, Soccer Ball Pen
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