Determination of aflatoxins in yogurt by multifunctional purification column and liquid chromatography

Application of aflatoxins in yogurt

Sample extraction：

Measure 4g yogurt sample into 50mL centrifuge tube, add 10mL extract (pure acetonitrile) and mix well

Vortex for 6min, put into centrifuge (8000r/min centrifuge for 10min), and take supernatant as sample extraction liquid

Sample purification：

Step 1: Add 5mL of sample extract to the test tube

Step 2: Insert the rubber tip of the purification column into the test tube from the top of the test tube, and press the purification column down to the bottom of the test tube

Step 3: Pour the purified sample extract from the upper part of the column into the sample bottle or EP tube

Step 4: Take 2mL of the purified extract, blow nitrogen until dry, redissolve with 1mL or 0.5mL of the initial mobile phase, filter through the microporous membrane, and analyze on the machine

HPLCDetection condition：

Y Mobile phase: phase A, water; B phase, acetonitrile-methanol (50:50, v:v)

Equal gradient elution condition: A, 68%; B, 32%

Y column: C18 column (column length 150mm, column inner diameter 4.6mm, packing particle size 5μm)

Flow rate: 1.0mL/min

Y column temperature: 40℃

Y Sample size: 50μL

Fluorescence detection: excitation wavelength: 360nm; Emission wavelength: 440nm

Experimental result：

Aflatoxin-labeled liquid chromatography

(AFM1 is 5ng/mL)

Comparison of negative yogurt sample and negative labeled sample

(AFM1 spiked concentration is 10ng/g)

The minimum detection limit, recovery rate and repeatability of yogurt samples

(AFM1 spiked concentration is 10ng/g)