Rapid Determination Of Nosiheptide Residue In Animal Muscle Tissues By High Performance Liquid Chromatography

Nosiheptide is a sulfur-containing polypeptide antibiotic produced by Streptomyces actuosus,which can effectively prevent and treat respiratory diseases and enteritis of animals.It has obvious effects on improving feed utilization and promoting growth of livestock and poultry.However,for pursuing the maximum of the economic interests,the phenomena of the abuse of nosiheptide as feed additives is often found,resulting in serious veterinary drug residues in animal-derived foods,even exceeding the maximum residue limit.In order to ensure the safety of animal food and human health,it is particularly important to strengthen the study on the analytical methods of nosiheptide residue.This research established a high-performance liquid chromatography（HPLC）method for rapid determination of the residue of nosiheptide in animal muscle tissues.A modified QuEChERS（Quick,Easy,Cheap,Effective,Rugged and Safe）method was adopted for the sample pretreatment.The pork,chicken and fish muscle samples were extracted with 1%acetic acid acetonitrile solution,followed by adding anhydrous magnesium sulfate and sodium chloride.After shaking and centrifugation,the supernatant was transferred to a new centrifuge tube and subjected to purify with alkaline alumina as the adsorbent,the supernatant was evaporated to near dryness,and the residue was re-dissolved with a 0.2%formic acid methanol solution.The solution was filtered through a 0.22μm filter and detected by HPLC with fluorescence detector（FLD）.Acetonitrile and 0.025%phosphoric acid solution were chosen as the mobile phase,nosiheptide was separated well by Agilent Poroshell 120 EC-C₈ column（250 mm×4.6mm i.d.,4μm）.The excitation and emission wavelengths were 357 nm and 515 nm,respectively,and the external standard method was used for quantification.The experimental results showed that the linearity of nosiheptide was good in the concentration ranges of 5～1000 ng/m L,with the correlation coefficient（r）was 0.9997.The limit of detection（LOD）and the limit of quantification（LOQ）of the developed method were 1.6μg/kg and 5μg/kg,respectively.At four spiked concentration levels of LOQ（5）,10,20 and 30μg/kg,the intra-day and inter-day recoveries of nosiheptide in pork,chicken and fish muscle samples were between 67.9%～91.6%and 72.3%～89.0%with the relative standard deviations ranged from 1.2%～9.8%and 4.1%～7.6%,respectively.In this study,a simple,convenient and reliable method based on QuEChERS approach was developed for the determination of nosiheptide residue in pork,chicken and fish samples using HPLC-FLD.The proposed method showed high sensitivity,accuracy and precision,which was successfully applied to the determination of nosiheptide residue in real animal muscle tissue samples.