基于酶生物传感器法检测果蔬中毒死蜱残留的提取工艺研究

使用自主研制的酶生物传感器型农残检测仪进行农药残留检测,通过筛选可测果蔬种类、调整优化样品处理大小、样品加标后静置时间、样品与提取液比例和振荡提取速度,提高检测用酶对农药的抑制敏感性,从而达到降低农药检出限、提高回收率的目的。主要设置的参数如下:样品处理方式分为打碎、切碎(切成1 cm×1 cm和1. 5 cm×3 cm大小);加标后静置时间为5 min、15min、30 min、60 min和90 min;料液比为1∶1、1∶2. 5、1∶5、1∶7. 5和1∶10;振荡提取速度为0 r/min、110 r/min、190 r/min和225 r/min;主要测定的农药为毒死蜱。结果发现,不同果蔬品种对固定化酶的抑制率影响小,样品大小为1 cm×1 cm、加标后静置时间为5 min、料液比为1∶1、加入提取剂后的振荡速度为190 r/min为最佳前处理方式组合。酶生物传感器农残检测仪能够满足快速检测果蔬中有机磷农药残留的需要。

Extraction process of detecting chlorpyrifos residues in fruits and vegetables based on enzyme biosensor

The pesticide residue detection was carried out by using a self-developed enzyme biosensor type detector. The inhibition sensitivity of enzyme to pesticide was improved by screening measurable fruit and vegetable species, adjusting and optimizing sample treatment size, static time after sample addition, ratio of sample to extract solution and oscillating extraction speed, so as to achieve the purpose of reducing the detection limit of pesticides and improving the recovery rate. The main parameters set were as follows: the sample treatment was divided into breaking and shredding (cut into 1 cm × 1 cm and 1.5 cm × 3 cm);the static time after adding standard was 5 min, 15 min, 30 min, 60 min and 90 min;the ratio of material to liquid was 1 ∶1, 1 ∶2.5, 1 ∶5, 1 ∶7.5;the oscillating extraction speed was 0 r/min, 110 r/min, 190 r/min and 225 r /min;and the main pesticide was chlorpyrifos. The results showed that different fruit and vegetable varieties had little effect on the inhibition rate of immobilized enzyme. The optimum combination of pretreatment methods were as follows: the sample size was 1 cm × 1 cm;the static time was 5 min after adding the standard;the ratio of material to liquid was 1 ∶1;the oscillating speed was 190 r/min. The self- developed enzyme biosensor for detecting agricultural residues could meet the needs of rapid detecting organophosphorus pesticide residues in fruits and vegetables.