Back Cover: Two chromatographic methods for the quantitative determination of some pesticides applied for cucumber pests in Egypt

Abstract

Sep. Sci. plus 2018, 1, 334–342 DOI: 10.1002/sscp.201800012 The cover picture shows two novel sensitive and accurate thin layer chromatography and HPLC methods that were used for monitoring the residues of four pesticides; mandipropamid, metalaxyl, thiophenate methyl and carbendazim, which are widely used to eliminate cucumber pests in Egypt; the first method is a HPTLC method, using silica gel plates as a stationary phase and hexane, methanol, acetone, and glacial acetic acid as a developing system; the second method is HPLC using isocratic elution and a mobile phase consisting of acetonitrile and potassium dihydrogen phosphate buffer with ultra violet detection. The proposed HPTLC and RP-HPLC methods are precise, accurate and validated analytical procedures. The advantage of the developed HPTLC method is that many samples can be run simultaneously using a small quantity of developing system, it shows a high selectivity in short analysis time. The suggested chromatographic methods can easily be used for quality analysis of cucumber to make sure the pesticides dose is within acceptable limit. Application of these methods to commercial formulations showed that excipients do not interfere with the determination of the studied pesticides and hence it can be used for their determination either in bulk powder or in commercial formulations.