Simultaneous analysis of endogenetic and ectogenic plant hormones by pressurized capillary electrochromatography

Pressurized CEC (pCEC) with UV detection was developed for the simultaneous analysis of endogenetic and ectogenic plant hormones. Effects of some crucial factors including mobile phase, buffer concentration, pH value and applied voltage on pCEC separation were investigated, respectively. Under the optimum conditions, namely a packed capillary column (3 microm Hypersil C(18), 45 cm total length with 100 microm id x 20 cm effective length) as the separation channel; ACN: 10 mmol/L phosphate (50:50, v/v, %) as the mobile phase, pH 4.0; pump flow rate 0.035 mL/min; separation voltage -10 kV; UV wavelength 222 nm, a complete separation of five hormones was accomplished. The pCEC assay presented good linearity (0.8-100 microg/mL), with LOD of 0.2 microg/mL and R in range of 0.998-0.999. Meanwhile, a lack-of-fit test was performed to evaluate these linear models. Results showed that no significant lack-of-fit was observed and these models were appropriate (alpha=0.05).