I. Ruhling et al., HPLC online reductive scanning voltammetric detection of diquat, paraquat and difenzoquat with mercury electrodes, FRESEN J AN, 364(6), 1999, pp. 565-569
To establish an electrochemical HPLC detection system which is suitable for
the voltammetric characterisation of unknown contaminants and food compone
nts at working potentials lower than -1 V, a modified flow-through cell for
the use of a hanging mercury drop electrode (HMDE) is described. The intro
duction of silanised glass capillaries and a new flow-channel design provid
e a high HMDE lifetime, which is recommended in HPLC detection. As test sys
tem the herbicides diquat, paraquat and difenzoquat and ethylviologen as in
ternal standard were measured using differential pulse voltammetry (DPV) de
tection to improve selectivity. Spiked water samples were analysed with vol
tammetric and UV-detection and results agreed well.