<abstract xmlns="http://www.w3.org/1999/xhtml"><p>Qat leaves are chewed on a daily basis by approximately 10 million inhabitants of different countries. This study investigated the persistence of three insecticides most used in qat production, imidacloprid, acetamiprid and methomyl. These chemicals were applied separately on plots of ten qat trees each at the recommended application rates. Samples of qat leaves were collected separately at time 0 (1 h post-treatment) and 1, 3, 7, 12, 19, 26 and 37 days after application. The residues of the investigated pesticides were extracted and then quantified by liquid chromatography (LC-MS/MS). The half-lives of imidacloprid, acetamiprid and methomyl were 12.2, 11.7, and 5.1 days, respectively. Overall, our findings showed that imidacloprid and acetamiprid were more persistent than methomyl in qat leaves. Taking into account the maximum residue limits (MRL) in lettuce, due to lack of MRL in qat leaves, the residue concentrations were below MRL for imidacloprid 7 days after application, and 1 day after application for acetamiprid and methomyl.</p></abstract>

Qat leaves are chewed on a daily basis by approximately 10 million inhabitants of different countries. This study investigated the persistence of three insecticides most used in qat production, imidacloprid, acetamiprid and methomyl. These chemicals were applied separately on plots of ten qat trees each at the recommended application rates. Samples of qat leaves were collected separately at time 0 (1 h post-treatment) and 1, 3, 7, 12, 19, 26 and 37 days after application. The residues of the investigated pesticides were extracted and then quantified by liquid chromatography (LC-MS/MS). The half-lives of imidacloprid, acetamiprid and methomyl were 12.2, 11.7, and 5.1 days, respectively. Overall, our findings showed that imidacloprid and acetamiprid were more persistent than methomyl in qat leaves. Taking into account the maximum residue limits (MRL) in lettuce, due to lack of MRL in qat leaves, the residue concentrations were below MRL for imidacloprid 7 days after application, and 1 day after application for acetamiprid and methomyl.

Persistence of imidacloprid, acetamiprid and methomyl in qat leaves

Center for Environmental Research and Studies, Jazan University, Jazan, Saudi Arabia

Department of Biology, Faculty of Science, Jazan University, Jazan, Saudi Arabia

Department of Environment, Faculty of Marine Science and Environment, Hodeidah University, Yemen

Hellenic Plant Protection Journal

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

{"article-title":"Persistence of imidacloprid, acetamiprid and methomyl in qat leaves"}

Qat leaves are chewed on a daily basis by approximately 10 million inhabitants of different countries. This study investigated the persistence of three...

Persistence of imidacloprid, acetamiprid and methomyl in qat leaves

Published Online: Jul 07, 2016

Page range: 51 - 59

Received: Nov 12, 2015

Accepted: Jan 07, 2016

DOI: https://doi.org/10.1515/hppj-2016-0006

Keywords
chat, degradation, half-life, insecticide, khat, qat

© 2016 A.J. Al-Rajab et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Persistence of imidacloprid, acetamiprid and methomyl in qat leaves

Published Online: Jul 07, 2016

Page range: 51 - 59

Received: Nov 12, 2015

Accepted: Jan 07, 2016

DOI: https://doi.org/10.1515/hppj-2016-0006

Keywordschat, degradation, half-life, insecticide, khat, qat

© 2016 A.J. Al-Rajab et al., published by De Gruyter Open

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License.

Keywords
chat, degradation, half-life, insecticide, khat, qat