氯氰菊酯在甘藍上的残留动态研究

气相色譜法氚-鈧源电子捕获检测器研究了氯氰菊酯在甘藍上的残留动态。甘藍生长中期喷施50ppm及90ppm氯氰菊酯,药剂在甘藍上消解緩慢,半衰期分別为6.0天、7.8天及8.3天,施药后一个月甘藍上仍残留約0.1～0.3ppm。氯氰菊酯的穿透性能很弱,只残留于施到药液的甘藍叶片表面,常用施药浓度25ppm下施药1～4次,施药后7天甘藍食用的结球部分均未检出,当施药浓度达50ppm时结球部分也仅有痕量残留,在非食用的外叶上残留量为0.2014～0.4929ppm。

THE RESIDUE BEHAVIOR OF CYPERMETHRIN ON CABBAGE

The residue behavior of cypermethrin on cabbage was investigatedwith gas chromatogaphy by using an electron capture detector. Duringthe growing season of the cabbage, when the plants were sprayedwith 50ppm and 90ppm of cypermethrin, the degradation rate ofpesticide was observed to be very slow, especially in the late stageof spraying. The half-life of cypermethrin on the leaf surface was6.0, 7.8 and 8.3 days, respectively. Residues found in cabbage 30 daysafter the treatment were about 0.1-0.3ppm. The experiment showedthat the cypermethrin residue was only on the surface of the plantbecause of it's comparatively low penetating ability. No pesticideresidues were detected on the edibal part of cabbage with 1-4applications of the recommended concentration (25ppm) and theresidues of cypermethrin were found to be trace only with 50ppmtreatment and the residues on the unedibal part of cabbage were foundto be 0.201 4-O.4929ppm.