The Determination Method Of Thiamphenicol And Florfenicol Residues And Their Elimination In Chicken Tissues

Chloramphenicol(CAP)was banned to use on food animal by all countries of the world,Thiamphenicol(TAP)and Florfenicol(FF)were applied extensively on livestock husbandry which belong to Chloramphenicols(CAPs).TAP and FF have important effect to control and treat disease of livestock and poultry.A lot of poison and side effect were found along with extensive application and with profound research of TAP and FF. Therefore,it was necessary to control the residues of TAP and FF in animal food in order to ensure health and safety of consumer.It was established that High performance liquid chromatography(HPLC)method for determining TAP and FF residues in chicken tissues.The different time(1st,3rd,5th,7th,9th,11th,13th,15th)after serial daily oral administration(dosage:200mg/Kg.b.w.d)for three days,the depletion in muscle,liver and kidney of TAP and FF were studied.1 HPLC method for determining TAP and FF residues was establishedTissue sample of muscle,liver and kidney were made for even plasm,the sample was extracted with ethyl acetate,defatted with n-hexane,re-extracted with ethyl acetate,and cleaned up by C₁₈Cartridge for Solid-Phase Extraction(SPE),the C₁₈Cartridge was eluted with methanol,then determined by HPLC.Chromatographic condition:the wavelength of ultraviolet detector(UVD)was 224nm,the column temperature was 30℃,flowing phase was 0.025mol·L^-1phosphoric acid/triethylamine(pH3.0)-acetonitrile(v/v,80:20),flowing rate was 1.0ml/min,injection volumn was 20μL,chromatogram cartridge was Waters Symmtry C₁₈(250mm×4.6mm i.d.,5.0μm).The retention time of TAP and FF when determined simultaneously was about 7.30min and 17.60min respectively.The limit of detection(LOD)of TAP in muscle,liver and kidney is 5ng·g^-1,10ng·g^-1and 10ng·g^-1 respectively.The LOD of FF in muscle,liver and kidney is 10ng·g^-1,10ng·g^-1and 10ng·g^-1 respectively.The calibration curves for the peak area is good linear relation in the range of 10～1000ng·g^-1,and the linear equations are:TAP:C=0.0200S-0.0076, (R=0.9997);FF:C=0.0226S-0.0275,(R=0.9991).The average recoveries and the average relative standard deviation(RSD)of TAP in deferent tissues are:in muscle 73.93%,9.50%,in liver 69.57%,9.97%,in kidney 72.64%,10.08%.The average recoveries and the average relative standard deviation(RSD)of FF in deferent tissues are:in muscle 73.58%,11.08%,in liver 70.26%,10.19%,in kidney 68.97%,8.20%.The coefficient of variation(C.V)within day and between day of TAP in deferent tissues are:in muscle 3.89%,6.27%,in liver 5.36%,9.14%,in kidney 5.96%,9.08%.The coefficient of variation(C.V)within day and between day of FF in deferent tissues are:in muscle 4.13%,7.78%,in liver 4.72%,11.13%,in kidney 5.01%,11.99%.The results showed this method was sensitive and reliable to determine TAP and FF residues in tissues(muscle,liver,kidney)of chickens.2 The TAP and FF residues elimination in broiler chickenThe different time(1st,3rd,5th,7th,9th,11th,13th,15th)after serial daily oral administration(dosage 200mg/Kg·d)for three days,the residue quantity in muscle,liver and kidney of TAP and FF were determined.The results showed:The TAP residue quantity in all tissues was higher than maximum residue limits(MRLs)on the 7th day after withdrawal.The TAP residue quantity in muscle was lower than MRLs on the 9th day after withdrawal.The TAP residue quantity in all tissues was lower than MRLs on the 11th day after withdrawal.The FF residue quantity in all tissues was lower than MRLs on the 5th day after withdrawal.Therefore,the withdrawal time(WDT)of primary form drug of was recommended as about eleven days,the WDT of primary form drug FF was about five days.But because TAP and FF have other metabolites residues,the actual WDT of TAP and FF would be longer than the WDT original form of TAP and FF.