Determination of ochratoxin in vinegar by multifunctional purification column and liquid chromatography

Application of ochratoxin in vinegar

Sample extraction：

Weigh 5g vinegar sample into 50mL centrifuge tube, add 0.5g sodium chloride, add 20mL acetonitrile and mix well

Ultrasonic extraction 30min, centrifuge (8000r/min centrifuge 20min), take the supernatant as the sample extraction solution

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 purified extract, blow nitrogen until dry, redissolve with 0.4mL of initial mobile phase, filter through microporous membrane, and analyze on the machine

HPLCDetection condition：

Mobile phase: acetonitrile - water - glacial acetic acid (96+102+2)

column: C18 column (column length 250mm, column inner diameter 4.6mm, packing particle size 5μm)

Flow rate: 1.0mL/min

column temperature: 35℃

Sample size: 50μL

Detection wavelength: excitation wavelength 333nm, emission wavelength 460nm

Experimental result：

Ochratoxin liquid chromatography

(Ochratoxin concentration was 20.0ng/mL)

Comparison of vinegar sample and vinegar labeling sample

(Ochratoxin concentration is 16.0ng/g)

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

(Ochratoxin concentration is 16.0ng/g)