主题：【求助】（已应助）请帮忙查四篇英文文献，谢谢

1、【标题】Multi-walled carbon nanotubes as efficient solid-phase extraction materials of organophosphorus pesticides from apple, grape, orange and pineapple fruit juices

【期刊名】Journal of Chromatography A, Volume 1211, Issues 1-2, 21 November 2008, Pages 33-42
【作者】Lidia M. Ravelo-Pérez, Javier Hernández-Borges and Miguel Ángel Rodríguez-Delgado 
2、【标题】Ultrasonic-assisted matrix solid-phase dispersion as an improved methodology for the determination of pesticides in fruits

【期刊名】Journal of Chromatography A, Volume 1212, Issues 1-2, 28 November 2008, Pages 145-149
【作者】J.J. Ramos, R. Rial-Otero, L. Ramos and J.L. Capelo
3、【标题】Extraction and determination of organophosphorus pesticides in water samples by a new liquid phase microextraction–gas chromatography–flame photometric detection

【期刊名】Analytica Chimica Acta, Volume 606, Issue 2, 14 January 2008, Pages 202-208
【作者】Mohammad Reza Khalili-Zanjani, Yadollah Yamini, Najmeh Yazdanfar and Shahab Shariati 
4、【标题】Development of a dispersive liquid–liquid microextraction method for organophosphorus flame retardants and plastizicers determination in water samples

【期刊名】Journal of Chromatography A, Volume 1166, Issues 1-2, 28 September 2007, Pages 9-15
【作者】M. García-López, I. Rodríguez and R. Cela