Studies On Bioconcentration And Elimination Of Sulfamethazine In Sturgeon (A.schrenkii)

In the study, N4 -acetyl-sulfamethazine(N4 -ACE-SM2) was synthesized, the determination method of sulfamethazine(SM2) and N4-ACE-SM2 in sturgeon muscle and water were developed, bioconcentration and depuration of SM2 in the sturgeon were completed at last.The results were asfollows:A sensitive high-performance liquid chromatographic method was developed for the quantitative determination of SM2 and N4-ACE-SM2 in sturgeon muscle tissue. SM2 and N4-ACE-SM2 were extracted with acetonitrile, and defatted with n-hexane, followed by an Alumina column clean-up procedure. The HPLC separation was carried out on an intertsil ODS column(250X4.6mm id 5um) using acetic acid-acetomtrile-water(0.05:24:76 v-v) as mobile phase with ultraviolet detection at 265nm. The recoveries of analysts at fortified level of 0.02ug.g^-1, 0.l0μg.g^-1 and 2.00μg.g^-1 from the muscle assay range from 80.4%⁸5.3% for SM2 and 88.4-96.0% for N4-ACE-SM2. The precision of the method was determined for both SM2(CV2.6%⁶.7%) and N4-ACE-SM2(CV 2.1%⁷.1%), the detection limits was 0.01 ug.g-1 for each drug. Detection limits of the assay were calculated to be three times the baseline noise from drug-free sampleA simple and rapid high-performance liquid chromatographic method for the simultaneous determination of the two drugs as above in river water was developed. The solution was adjusted to pH value of 6.5,followed by extracted with ethyl acetate, evaporated to dryness and dissolved the residue with mobile phase. The solution was subsequently subjected to separate HPLC assay for each drug. The recoveries of analytes from the water assay at the fortified level of 0.02μg.mr , 0.l0μg.ml" and 2.00μg.ml-1 for both drugs range from 93.4%⁹5.7% for SM2 and 94.4-97.0% for N4-ACE-SM2. The precision of the assay method was determined for SM2(CV%2.6-6.2) and N4-ACE-SM2(CV%2.4-5.1), the detection limit was O.Olug.ml-1 for both drugs. Detection limits of the assay were calculated to be three times the baseline noise from drug free sampleA steady-state bioconcentration and depuration of sulfamethazine (SM2) in the sturgeon (A. schrenkii) was conducted in a flow-through aqueous conditions. Three treated groups of fish were exposed to aqueous concentration of 10.00μg.ml-1, l.00μg.mr and 0.l0μg.ml -1of SM2 respectively during 8-day uptake period and then exposed to blank water during the sequent 5-day depuration period. The SM2 and its main metabolite N4-ACE-SM2 in both fish muscle and water were simultaneously determined by HPLC.The data were assayed with SAS 6.21 software for windows. The bioconcentration phase fits the Y=(K1/K2).Cw.(l-e-k2t) and the depuration phase illiterately fits the Y=Cm.e-k2t. Parameters of the absorbent velocity constant(K1day-1), elimination velocity constant(K2,day-1 ), bioconcentration in fish muscle(BCFm) and elimination half time(T1/2,day) of the high concentration group were 0.84, 0.70, 1.19 and 0.98 respectively, and parameters of medium concentration group were 0.51, 0.85, 0.61 and 0.81, as well as 0.48, 0.88, 0.55 and 0.79 for the low concentration group. Three treated groups attained steady-state concentration by about 3-4 days. BCFmof lower concentration was, by comparison, higher than that of higher concentration group. The calculated biodegradation index of groups of 10.0#g.mr' and l.0#g.mr^-1 were 3.16% and 3.72%, with no detection biodegradation in the low concentration group. The elimination half-time(T_1/2) of the three treatment groups were between 0.79 to 0.98 days.In conclusion parameters above shows that sturgeon absorbs a little SM2 and eliminates fast, it also indicates that SM2 will neither bioconcentrate in individual aquatic organisms nor biomagnify i n the food chain.