Study On Residual Detection Method Of Phenylethanolamine A In Animal Foods

Residues and abuse of forbidden drugs are main problem in the quality and safety of animal products at home and abroad.?-agonists as one of the banned drugs in China has been listed in routine monitoring.Phenylethanolamine A is a new type of ?-agonists,the Ministry of Agriculture has forbidden the use of phenylethanolamine A in animal feed and water by the 1519 Announcement.The drug residue can be transferred to human by food chains,which would lead to a great threaten to human,such as nausea,dizziness,limb weakness,hand tremor and other symptoms of poisoning.Long-term consumption may lead to mutations in the body's chromosomes,induced malignant tumors,etc.Nowadays,the testing standards and specifications have been issued to detect the use of phenylethanolamine A in animal feeds.But there is no standard for the determination of phenylethanolamine A in animal foods.In this paper,the selection and optimization of two different pretreatment methods for phenylethanolamine A in animal foods were studied,including pork,pork-liver,pork-kidney,mutton and beef.The detection method of phenylethanolamine A of high performance liquid chromatography-tandem mass spectrometry was established by using phenylethanolamine A-D3 as the internal standard in animal foods.(1)In the solid phase extraction pretreatment method,the homogenized samples were ultrasonic extracted by 10%formic acid methanol twice for 20 min,then purified and accumulated by PCX solid phase extraction column.5%ammonia methanol eluent was collected at 40? nitrogen drying.The residue was rinsed with 1 mL of methanol and separated by ACQUITY UPLC BEH C18(50x2.1 mm,1.7 ?m).The reconstitution fluid was gradient eluted with 0.1%formic acid water-methanol as the mobile phase at the flow rate of 0.3 mL/min,which was qualitatively and quantitatively analyzed under multiple reaction monitoring.The results showed that there was a good linear relationship between the peak area ratio of phenylethanolamine A to phenylethanolamine A-D3 and its concentration(correlation coefficient R2>0.999)at the linear range of 0.1-40.0 ?g/kg.The recovery rates of five kinds of blank matrices were more than 90%,the limit of detection was 0.005 ?g/kg and the limit of quantification was 0.01 ?g/kg.(2)In the QuEChERS pretreatment method,the homogenized samples were added 10 mL of acetonitrile and 2 g of NaCl,and taken the acetonitrile layer to another centrifuge tube after vortexing and centrifuging.Then 10 mL of n-hexane was added in it.After vortexing and centrifuging,n-hexane was discarded.Then 1 mL of acetonitrile layer of it was taken in 5 mL centrifuge tube which was added PSA and anhydrous sodium sulfate for purification,in addition to water.The supernatant after centrifugation was filtered through a 0.2 ?m filter and ready on the machine.The results showed that there was a good linear relationship between the peak area ratio of phenylethanolamine A to phenylethanolamine A-D3 and its concentration(correlation coefficient R2>0.999)at the linear range of 0.1?40.0 ?g/kg.The recoveries were 85%?120%,and the limit of detection was 0.05?g/kg and the limit of quantification was 0.1 ?g/kg.(3)The substrate effect of high and low concentration of phenylethanolamine A treated by two different pretreatment methods was evaluated.Two pre-treatment methods that did not add phenylethanolamine A-D3 as the internal standard are affected by the matrix effect seriously.While the two pre-treatment methods with the addition of internal standard were less affected by the matrix effect,and the SPE method was superior to the QuEChERS method.At the same time,the SPE method has higher sensitivity than the QuEChERS method,while the QuEChERS method is simpler,faster and time-saving than the SPE method.In summary,the establishment of detection method of phenylethanolamine A in animal food residues provides a guarantee for food safety,and has important practical significance.