渔业水域氯氰菊酯的检测方法及其消解动态

Determination and residual elimination of cypermethrin in fishery waters

根据氯氰菊酯(Cypermethrin)对斑马鱼、剑尾鱼、鲫鱼、罗非鱼、鳜鱼5种鱼的安全浓度范围(0 001～1 06μg/L),建立相应的毛细管气相色谱检测方法,用于水体中氯氰菊酯消解动态试验检测,该方法的最小检测水平为1×10-3μg/L,氯氰菊酯质量浓度在0 1～10μg/L时线性相关系数为0 9993,平均回收率87 9%,变异系数14 7%。对25℃恒温条件下的残留消减实验结果进行回归分析,结果表明,水体中氯氰菊酯的残留消解动态可用三次曲线模型Y=6 1053-0 1566X+0 0035X2-(4 8068E-05)X3表达。35℃、15℃恒温条件下,同样是三次曲线模型的相关指数R2最大。上述3种不同温度下建立的消解动态方程导出的氯氰菊酯残留半衰期分别为20d、29d和31d,表明氯氰菊酯水中残留半衰期随温度升高而下降。

Pyrethroid is widely used in aquiculture,and there is considerable inertial usage,however,there lacks research of influence on water environment and elimination trend in the water environment.In this paper,an optimized gas chromatographic with electron-capture detection method is described for the determination of cypermethrin in fishery water.The cypermethrin was extracted with ligroin.The relationships between peak area and pressure and temperature on GC were optimized by the even design examination U_5(54) and computer.The results were expressed by non-linear model Y=-3.30×108+2.59×106X_1-5.00×103 X2_1+5.66×105X_2+1.64×104 X2_2.Derivation partial derivative of temperature(X_1)and pressure(X_2)are 259℃ and 119.3kPa.The temperatures of injector and detector were maintained at 260 and 280℃,respectively.The method corresponded to the safe concentration range of Cypermethrin to Siniperca chuastsi,Danio rerio,Carassius auratus,Tilapia and Xiphophorus helleri,which was between 0.001μg·L-1 and 1.06μg·L-1.The detection limit was 1×10-3μg· L-1.In the concentration range of 0.1-10μg·L-1,the correlation coefficient was 0.9993,and the average recovery was 87.9%,and the relative standard deviation was 14.7%.The method was applied to the concentration determination of cypermethrin residue elimination trends experiment in water.The test was carried through in 10L glass containers,adopting the water sample and determined concentration of cypermethrin on days 1(after give cypermethrin 1h),2,5,8,12,16,22,34,47 during the experiment,and three control groups were set according to water temperature.At 25℃,the result of regression showed that the model of cypermethrin residues eliminating trends was Y=6.1053-0.1566X+0.0035X2-(4.8068E-05)X3.When the water temperatures were 35℃ and 15℃,the results of regression of cypermethrin residue eliminating trend experiment showed that their curve models were cubic,too.The R2 square of cubic models was the largest among fit curve models.According to the calculated results of cubic models of cypermethrin eliminating trend,the half lives of cypermethrin were not the same at different temperatures.They were,respectively,20d,29d and 31d at 15℃,25℃ and 35℃ in water.The half lives of cypermethrin descended along with the temperature increasing.