Abstract
A new method for the separation of a mixture of different herbicides (propham, chlorpropham, asulam, metamitron, linuron, and maleic hydrazide) using MEKC is proposed. A baseโline separation for the mixture of herbicides is achieved in less than six minutes. The detection limits obtained for all the herbicides were lower than 1.0โ
ฮผM using UV detection. This separation method was used for the determination of maleic hydrazide in potato samples. If a dual (UVโelectrochemical) detection system is employed, chlorpropham can be also detected. The results obtained showed that electrochemical detection was ten folds more sensitive than UV detection for maleic hydrazide. The detection limit of the proposed method for maleic hydrazide employing electrochemical detection was 1.3โ
ฮผg g^โ1^, this value is lower than 50โ
ฮผg g^โ1^, which is the maximum residue level permitted for this plant growth regulator in potato samples. The results obtained in the work clearly demonstrate the advantage of using electrochemical detection coupled to capillary electrophoresis, using this detection the concentration limits are not compromised by miniaturization and the components required are simple and inexpensive.