The immunoaffinity column can selectively adsorb aflatoxin M1 from the sample solution, thereby purifying the sample. The purified sample solution can then be directly used for HPLC or LC-MS/MS analysis.
Immunoaffinity columns can be used in combination with HPLC or LC-MS/MS to achieve rapid testing, and to increase signal-to-noise ratio and improve the accuracy of the detection method.
1. Overview:
Aflatoxins are toxic metabolites of a class of fungi (such as Aspergillus flavus and Aspergillus parasiticus). They are highly carcinogenic and are found mainly in grains, peanuts, nuts, cottonseeds, animal feed, vegetable oils, as well as animal tissues and blood. Among them, Aflatoxin B1 (AFT B1) ranks first in terms of toxicity, carcinogenicity and frequency of contamination. Aflatoxin M1 is the hydroxylated metabolite of Aflatoxin B1 and a strong carcinogen. Cow’s milk and its products are prone to Aflatoxin M1 contamination.
2. Principle:
The basis of the measurement is the antigen-antibody reaction. Antibodies are connected to the column and the aflatoxin in the sample is extracted, filtered, and diluted, and then passed slowly through the aflatoxin immunoaffinity column. The toxins bind to the antibodies in the column and the immunoaffinity column is then washed to remove other unrelated substances that have not been bound. Aflatoxin is then eluted with methanol and injected into an analytical instrument for detection.
3. Components of the kit:
Each kit contains Aflatoxin immunoaffinity columns of various specifications and 1 instruction manual.
4.Necessary items not provided in the box:
- Equipment
- HPLC/LC-MS/MS
- Nitrogen gas evaporatorapparatus
- Nitrogen gas tank and pressureregulator
- Air-pressure controller bracket
- Air pump
- Balance with 0.001greadability
- High-speed freezing centrifuge (can be set to 10°C, 7, 500RPM)
- Centrifugetube:50-mL
- Constant temperature incubator or water bath (can be set to 35–37℃)
- High-speed homogenizer (maximum speed> 10,000 RPM) or shaker
- Grinder
- pH meter (or pH testpaper)
- Sieving screen:2mm
- Graduated cylinder: 100 mL/10mL
- Funnel: 50mL
- Syringe: 10 mL/20mL
- Homogenization flask (or 250-mL conical flask withpestle)
- Vias andtubes
- Rapid qualitative filterpaper
- Microfiber filter paper (e.g. Whatman934-AH)
- Column holder and syringe connector plug (for use with immunoaffinitycolumns)
5.2 Reagents
- Methanol (CH3OH): AnalyticalGrade
- Acetonitrile (CH3CN): ChromatographyGrade
- Sodium chloride (NaCl): AnalyticalGrade
- Hydrochloric acid (HCl): AnalyticalGrade
- Sodium hydroxide (NaOH): AnalyticalGrade
- Potassium chloride (KCl): AnalyticalGrade
- Potassium dihydrogen phosphate (KH2PO4): AnalyticalGrade
- Disodium hydrogen phosphate dodecahydrate (Na2HPO412H2O):Analytical Grade
- Distilled or deionizedwater
Note:
- Allow the immunoaffinity column to return to room temperature(22 to 25°C) before
- The immunoaffinity column should be stored at 2 to 8°C, do not freeze.
- Dot use any expired immunoaffinity
- The sample volume can be increased or decreased appropriately as required, and the volume of the extraction solution should be adjusted
- Column capacity: 100 ng, when the content of the toxin in the sample divided by the dilution factor is higher than the column capacity, it is necessary to reduce the volume of the sample solution appropriately, and
- The pH of the loading solution of the immunoaffinity column should be within the range of 6 to 8. If it deviates from this range, the pH should be adjusted with dilute hydrochloric acid or dilute sodium
- Maintaining consistency (such as polarity, pH, and concentration) between the test solvent loaded into any analytical instrument and the mobile phase can help eliminate any adverse solvent
- WARNING: Aflatoxin is toxic and carcinogenic; protective equipment such as gloves and masks should always be used during handling.
- Vessels and tools used to handle toxin solutions should be completely immersed in a sodium hypochlorite solution (5% v/v) overnight.
- Ensure the LC-MS/MS is clean and the tubing is primed appropriately for each
- Follow appropriate instrument precautions if using
- If milk powder samples are difficult to dissolve, incubate at 50°C for 30 minutes. If it is still not dissolved, increase the proportion of water appropriately.
- For samples that are particularly turbid after centrifugation, increase the rotation speed or increase the centrifugation time appropriately.