Establishment Of Toltrazuril Detection In Feeds By High Performance Liquid Chromatography

Toltrazuril is a symmetrical triazinone compound. It is highly effective against some protozoal species including coccidian. The anti-coccidial index (ACI) of toltrazuril was apparent, even more than 180.,Nowadays, problems of drug residues in animal products,drug resistance of pathogenic microorganisms, the potential hazards of consumer health and the environment are becoming more and more serious because of the.over use of feed additives, which have been used as veteratary medicine. Non-standard application of veterinary medicine, increase veterinary medicine dose freely, still use feed which containing drugs during the withdrawal period and the use of unapproved drug additives are the main source of veterinary drug residues. Therefore, strictly limit the use of veterinary drugs variety and enhance the detection of additives in feed is the main management tool. Up to now, China has not yet established and published the agricultural industry standards about toltrazuril in feed. So it is necessary to establish and regulate the testing methods, which also can enhance the supervision of toltrazuril in feeds.The Solid phase extraction-high performance liquid chromatography (SPE-HPLC) method was confirmed to detect toltrazuril by means of optimizing the conditions of the extraction, purifying extracts and seperating toltrazuril. After extracted in 20 mL acetonitrile by ultrasound for 10 min and then cleaned up with silica SPE column, toltrazuril was separated on C18 column with UV detector at 240 nm, with a column temperature of 30℃, using acetonitrile and 0.2% acetic acid (70:30, V/V) as mobile phase at a flow rate of 1.0 mL/min. The results indicate that the average recoveries of toltrazuril ranged from 86.91%±3.95%～105.10%±3.26%, with RSD of 1.04%～7.47 %. The linear relationships of toltrazuril were fine between 0.1μg/mL～25μg/mL. The HPLC limit of detection, based on a S/N of 3,was estimated to be 0.150μg/mL for toltrazuril. The limit of quantitation, based on a S/N of 10, was estimated to be 0.250 mg/kg for toltrazuril. This developed method was tested to be a high sensitivity, good accuracy and precision. The established SPE-HPLC method is applicable to detect the formula feeds, the concentrated feeds and the premixes contained lower upto higher content of toltrazuril.