Studies On The Analytical Methods Of Tetracycline Antibiotics In Feed

Antibiotic residues in food is one of hot topics in the research of food safety system in China recently. The complicated matrix of the sample, the low concentration of the determinants and the variety of the samples are main characteristics of food analysis. So the samples can not be detected directly, they must be pretreated properly. To develop a sample preparation is the significant precondition of the rapid, accurate, sensitive analysis, and it is a hot topic in food safety analysis.The abuse of an additive of antibiotics such as tetracycline, in feed is the main cause of the antibiotic residues in food. In this paper, it detailedly studied tetracycline which extracted by subcritical water and established two methods of high performance liquid chromatography and chemiluminescence .The main results of this thesis are as follows:(1) High performance liquid chromatography for the determination of tetracycline residues in feed was established. Tetracycline was detected at 355 nm by ultraviolet detector. CH3CN-0.01 mol/L NaH2PO4 (pH=2.5, 25:75 volume ratios) was used as mobile phase at a flow rate of l.00 mL/min, and the sample inject was 20 mL each time.(2) The extraction of tetracycline residues from feed by subcritical water was studied. The experiment factors such as temperature, extraction time, acid and the composition of extraction solvent, were investigated. The optimal condition was obtained to be: 6.00 ml pH=2 deionzed water, under 100℃for about 5 min. Under the optimal condition, the concentration of tetracycline residues was obtained by standard addition method, and the recovery was investigated and the value is between 80%~92%. Compared with the National Standard Method of People's Republic of China (GB/T 14931.1-94), the subcritical water extraction method exhibits following advantages: short extraction time and high efficiency, good precision, easy operation and environment-friendly and so on.(3) Chemiluminescence was developed for the determination of tetracycline. The experiment parameters of the chemiluminescence of tris (2, 2′-bipyridine) ruthenium (II) by tetracycline were also optimized as follows: the concentrations of Ru(bipy)32+,Ce(SO4)2 and H2SO4 were 8.8 mg/L, 4 m mol/L and 60 m mol/L, respectively. Finally, the method was successfully used to measure tetracycline in practical pharmaceutical formulation.