Aflatoxin B1 detection protocol in edible oil

After the aflatoxin M1 of Mengniu dairy products exceeded the standard, some products produced by three companies in Guangdong Province were found to have exceeded the carcinogen aflatoxin. Recently, the Shenzhen market supervision department also detected 7 batches of food aflatoxin in the local area, and found that the food service industry still has the problem of using oil.

Aflatoxin has become a widespread problem that plagues the food industry. Food is a matter of food, food safety is related to thousands of households, and it is related to the survival of food companies. The content of aflatoxin B1 in edible oil exceeds the standard, which is derived from the mildew of peanut raw materials, which may be the process of planting, transporting and storing peanuts. Due to the hot and humid weather, it causes growth and reproduction of Aspergillus flavus and Aspergillus parasiticus. Aflatoxin is a carcinogen that is 10 times more toxic than potassium cyanide and 68 times more arsenic. The toxicity of aflatoxin can be destroyed when the processing temperature exceeds 280 °C. The general cooking method can't be removed. Only the aflatoxin pollution at the source is the best solution.

The limit of aflatoxin B1 is clearly defined in the previous relevant food hygiene standards, including: corn, peanut kernels, peanut oil should not exceed 20ug/kg; rice and other edible oils should not exceed 10ug/kg; other food, Beans and fermented foods shall not exceed 5 ug/kg; aflatoxin B1 shall not be detected in infant milk substitute foods. As a domestic professional supplier of mycotoxin detection technology and product services, in 2010, Tellabs Technology invested in the establishment of a "test application laboratory", focusing on food safety incidents, especially on the safety of mycotoxins, in order to quickly propose solutions. .

Tellabs Technology proposes the following solutions to the recent problem of excessive aflatoxin in edible vegetable oils.

Immunoaffinity column + KRC photochemical post-column derivatization

1 Introduction

The Pribofast Aflatoxin Total Immunoaffinity Column selectively adsorbs toxins from the sample solution for very targeted purification of the toxin sample, which can then be used to efficiently determine aflatoxin B1 using the HPLC/FLD+KRC post-column derivatization system. , B2, G1, G2 concentration, improve the accuracy and sensitivity of detection.

2. Immunoaffinity column / KRC derivative method features:

PriboFast Aflatoxin total (B+G) immunoaffinity column { spik recovery >90%}

· Strong specificity makes sample purification excellent;

· Use the immunoaffinity column operator to make the sample clean quickly and improve the detection efficiency
l · HPLC+FLD+KRC post-column derivatization, effectively improve detection sensitivity and achieve a lower detection limit (aflatoxin B1 0.05ppb).
l · Derivatization is convenient, and photochemical derivatization does not require the use of derivatization reagents (usually derivatization is required after electrochemical column derivatization, the analysis cost is high, the operation is troublesome, and the instrument failure rate is high).

· High recovery rate, reaching over 90%.

3. Introduction of the immunoaffinity column method:

1) Sample processing ( plant oil )

· Accurately weigh 25.0 g of sample in a 250 mL stoppered conical flask

· Add 5g of sodium chloride and add methanol / water, and extract with high speed and homogenizer for 2min;

· Quantitative filter paper filtration, and accurately transfer 15 M l of filtrate and add 30 mL of water to dilute and mix;

• Filter 1-2 times with glass fiber filter paper until the filtrate is clear and ready for use.

2) Install the warmed immunoaffinity column on the pump flow frame for column purification: after the ribbofast aflatoxin B1 immunoaffinity column (IAC-011-3) activation, elution, elution three steps, elution The solution can be directly used for HPLC detection;

3) Determination: Direct injection of HPLC, direct recording of aflatoxin B1 concentration by fluorescence detector with aflatoxin-specific chromatography column and KRC photochemical column derivatization;

Pribofast KRC post-column derivatizer and HPLC parameters (in accordance with GB23212-2008)

Pribofast KRC-25 Post-column Photochemical Derivatives Wavelength: 254 nm
HPLC-Column column: Aflatoxin-specific column 150 x 4.6 mm; C-18
Mobile phase: Methanol / water (45/ 55 v/v)
Flow rate: 1.0 mL/min Column temperature: 30 °C
Injection volume: 20μL
Fluorescence detector: λ-excitation wavelength: 365 nm λ-emission wavelength: 440 nm

Liquid chromatograph detection configuration

High performance liquid chromatography with fluorescence detector

Pribofast KRC-25 post-column photochemical derivatization unit with 1ml reaction cell, nano tube 254nm

Aflatoxin-specific column C18 150 x 4.6 mm