Capillary liquid chromatography of chlorophenoxy acid herbicides and their esters in apple juice samples after preconcentration on a cation exchanger based on polydivinylbenzene-N-vinylpyrrolidone.
A capillary liquid chromatography (cLC) method with gradient elution has been used to determine chlorophenoxy acid herbicides: 2,4-dichlorophenoxyacetic acid, 4-chloro-2-methylphenoxyacetic acid, 2-(2,4-dichlorophenoxy)propanoic acid, 2-(4-chloro-2-methylphenoxy)propanoic acid, 4-(2,4-dichlorophenoxy)butanoic acid, 4-(4-chloro-2-methylphenoxy)butanoic acid, 2-(2,4,5-trichlorophenoxy)propanoic acid, 2,4-dichlorophenoxyacetic-1-methyl ester and 2,4-dichlorophenoxyacetic-1-butyl ester in spiked apple juice samples with amounts between 0.025 and 0.150 mg kg(-1) of each herbicide. Clean-up and preconcentration of acid and esters were carried out in an Oasis MCX polymer. Detection limits obtained by cLC, between 0.005 and 0.018 mg kg(-1), allowed the determination of chlorophenoxy acids and their esters in apple juice samples around the levels permitted by the European Regulations, with recoveries in the range 84-99% and RSDs between 1 and 4%.
Departamento Química Analítica, Facultad de Ciencias Químicas, Universidad Complutense de Madrid, Ciudad Universitaria s/n, E-28040 Madrid, Spain.
N
N
Rosales-Conrado
M E
ME
León-González
L V
LV
Pérez-Arribas
L M
LM
Polo-Díez
D001628:Beverages / Q000032:analysis*; D002411:Cation Exchange Resins; D006540:Herbicides / Q000032:analysis*; D027845:Malus; D011760:Pyrrolidinones / Q000737:chemistry*; D013343:Styrenes / Q000737:chemistry*
D002411:Cation Exchange Resins; D006540:Herbicides; D011760:Pyrrolidinones; D013343:Styrenes; C042670:N-vinyl-2-pyrrolidinone; C056745:poly(divinylbenzene)