Analytical Sciences

Abstract − Analytical Sciences, 32(7), 719 (2016).

Detection of Organophosphorus Pesticides with Colorimetry and Computer Image Analysis
Yanjie LI,*1,*2 Changjun HOU,*1 Jincan LEI,*3 Bo DENG,*4 Jing HUANG,*1 and Mei YANG*1
*1 Key Laboratory of Biorheology Science and Technology, Ministry of Education, College of Bioengineering, Chongqing University, Shazhengjie 174, Chongqing, 400044, P. R. China
*2 College of Life Science and Engineering, Chongqing Three Gorges University, Shalong Road 780, Wanzhou, 404100, P. R. China
*3 Postdoctoral Station of Science and Technology of Instrumentation, College of Optoelectronic Engineering, Chongqing University, Shazhengjie 174, Chongqing, 400044, P. R. China
*4 National Engineering Research Center of Solid-State Brewing, Luzhou Laojiao Group Co. Ltd., Nanguang Road, Luzhou, Sichuan, 646000, P. R. China
Organophosphorus pesticides (OPs) represent a very important class of pesticides that are widely used in agriculture because of their relatively high-performance and moderate environmental persistence, hence the sensitive and specific detection of OPs is highly significant. Based on the inhibitory effect of acetylcholinesterase (AChE) induced by inhibitors, including OPs and carbamates, a colorimetric analysis was used for detection of OPs with computer image analysis of color density in CMYK (cyan, magenta, yellow and black) color space and non-linear modeling. The results showed that there was a gradually weakened trend of yellow intensity with the increase of the concentration of dichlorvos. The quantitative analysis of dichlorvos was achieved by Artificial Neural Network (ANN) modeling, and the results showed that the established model had a good predictive ability between training sets and predictive sets. Real cabbage samples containing dichlorvos were detected by colorimetry and gas chromatography (GC), respectively. The results showed that there was no significant difference between colorimetry and GC (P > 0.05). The experiments of accuracy, precision and repeatability revealed good performance for detection of OPs. AChE can also be inhibited by carbamates, and therefore this method has potential applications in real samples for OPs and carbamates because of high selectivity and sensitivity.