Selective and Sensitive Chemiluminescence Determination of Mcpb: Flow Injectin and Liquid

Two new chemiluminescence methods are described for the determination of herbicide MCPB. Firstly, a flow injection chemiluminescence (FI-CL) method is proposed. In this method, MCPB is photodegraded with a UV lamp and the photoproducts formed provide a great chemiluminescence signal when they react with ferricyanide in basic medium. Secondly, an HPLC chemiluminescence (HPLC-CL) method is proposed. In this method, before the photodegradation and CL reaction, the MCPB and other phenoxyacid herbicides are separated in a C18 column. The experimental conditions for the FI-CL and HPLC-CL methods are optimized. Both methods present good sensitivity, the detection limits being 0.12 μg L -1 and 0.1 μg L -1 (for FI-CL and HPLC-CL, respectively) when solid phase extraction is applied. Intraand interday relative standard deviations are below 9.9%. The methods have been satisfactorily applied to the analysis of natural water samples. FI-CL method can be employed for the determination of MCPB in simple water samples and for the screening of complex water samples in a fast, economic and simple way. The HPLC-CL method is more selective, and allows samples that have not been resolved with the FI-CL method to be solved.